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[[Image:Swarm-satellite.jpg|thumb|right|300px|The "Swarm" satellites have been flying around Earth since Fall of 2013. Credit: Christoph Seidler, ESA/DTU.{{tlx|fairuse}}]]
"Three [Swarm] satellites of the European Space Agency (ESA) have measured the magnetic field of Earth more precisely than ever before."<ref name=Seidler>{{ cite web
|author=Christoph Seidler
|author2=translated by Anne-Marie de Grazia
|title=Earth's weakening magnetic field
|publisher=Q-Mag.org
|location=
|date=19 June 2014
|url=http://www.q-mag.org/earths-weakening-magnetic-field.html
|accessdate=2014-10-21 }}</ref>

Alloys included here may be "a combination of two or more elements, at least one of which is a metal", an "admixture", anything "made by combining several things", a "substance made from any combination of ingredients" or "a substance made from the chemical combination of elements".
{{clear}}

==Explorations (Earth)==
{{main|Exploration geology}}
[[Image:Togo phosphates mining.jpg|thumb|300px|Phosphate mining in Togo is a last phase of exploration geology. Credit: Alexandra Pugachevsky.{{tlx|free media}}]]
"Exploration geology is the single most important and very first phase of mining. It begins by identifying what mineral/minerals is/are to be exploited, their geological setting, approximate size of orebody required and potential areas. Once these factors are considered, funds are required to finance the exploration project. Usually exploration companies list on stock exchanges to raise the required capital. Exploration begins by firstly gathering any possible data available on the resource, area, local geology usually from the geological survey, from satellite imagery as well as previous scientific work. The next phase usually involves geotechnical prospecting which makes use of either seismic, electrical, magnetic, radioactive or density techniques. Once a suitable area has been found, holes are drilled and the core retrieved is logged and correlated against other logs to form a model of the orebody. Once sufficient holes have been drilled and the ore tested for qualities, feasibility studies and due diligence work can commence."<ref name=MuhammadMoolla>{{ cite book
|author=Muhammad moolla
|title=Topic:Mining
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=15 May 2009
|url=http://en.wikiversity.org/wiki/Wikiversity:RFD#Dominant_group
|accessdate=2016-05-05 }}</ref>
{{clear}}

==Alloys==

Alloys are defined by a metallic bonding character.<ref name=Callister>Callister, W.D. "Materials Science and Engineering: An Introduction" 2007, 7th edition, John Wiley and Sons, Inc. New York, Section 4.3 and Chapter 9.</ref>

'''Def.''' a "metal that is a combination of two or more elements, at least one of which is a metal"<ref name=AlloyWikt>{{ cite book
|author=[[wikt:User:Bluelion~enwiktionary|Bluelion~enwiktionary]]
|title=alloy
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=7 May 2003
|url=https://en.wiktionary.org/wiki/aloy
|accessdate=30 June 2022 }}</ref> or an "admixture"<ref name=AlloyWikt1>{{ cite book
|author=[[wikt:User:Widsith|Widsith]]
|title=alloy
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=1 May 2012
|url=https://en.wiktionary.org/wiki/alloy
|accessdate=30 June 2022 }}</ref>, "instance of admixing [mingling], a mixing-in of something"<ref name=AdmixtureWikt>{{ cite book
|author=[[wikt:User:Jtle515|Jtle515]]
|title=admixture
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=3 March 2012
|url=https://en.wiktionary.org/wiki/admixture
|accessdate=30 June 2022 }}</ref> is called an '''alloy'''.

'''Def.''' anything "made by combining several things",<ref name=CompoundWikt1>{{ cite book
|author=[[wikt:User:Paul G|Paul G]]
|title=compound
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=8 November 2005
|url=https://en.wiktionary.org/wiki/compound
|accessdate=30 June 2022 }}</ref> a "substance formed by chemical union [bonding]<ref name=CompoundWikt3>{{ cite book
|author=[[wikt:User:Quercus solaris|Quercus solaris]]
|title=compound
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=12 February 2022
|url=https://en.wiktionary.org/wiki/compound
|accessdate=30 June 2022 }}</ref> of two or more ingredients [elements]<ref name=CompoundWikt3/> in definite proportions by weight",<ref name=CompoundWikt2>{{ cite book
|author=[[wikt:User:DCDuring|DCDuring]]
|title=compound
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=27 November 2010
|url=https://en.wiktionary.org/wiki/compound
|accessdate=30 June 2022 }}</ref> a "substance made from any combination of ingredients",<ref name=CompoundWikt3/> "a substance made from the chemical combination of elements"<ref name=CompoundWikt>{{ cite book
|author=[[wikt:User:DavidL2|DavidL2]]
|title=compound
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=12 October 2004
|url=https://en.wiktionary.org/wiki/compound
|accessdate=30 June 2022 }}</ref> is called a '''compound'''.

Sulfur combines readily with iron to form iron sulfide, which is very brittle, creating weak spots in the steel.<ref name=Verhoeven>{{cite book|author=Verhoeven, John D.|title=Steel Metallurgy for the Non-metallurgist
|date=2007|publisher=ASM International|{{isbn|978-1-61503-056-9}}|page=56|url=https://web.archive.org/web/20160505065853/https://books.google.com/books?id=brpx-LtdCLYC&pg=PA56 }}</ref>

The physical properties, such as density, reactivity, Young's modulus of an alloy may not differ greatly from those of its base element, but engineering properties such as tensile strength,<ref name=Mills>Mills, Adelbert Phillo (1922) ''Materials of Construction: Their Manufacture and Properties'', John Wiley & sons, inc, originally published by the University of Wisconsin, Madison</ref> ductility, and shear strength may be substantially different from those of the constituent materials.

==Actiniums==
[[Image:Actinium sample (31481701837).png|thumb|right|250px|Actinium-225 medical radioisotope held in a v-vial at ORNL; note: the blue glow that originates from the ionization of surrounding air by alpha particles. Credit: [https://www.flickr.com/people/37940997@N05 Oak Ridge National Laboratory].{{tlx|free media}}]]
[[Image:Uraninite-39029.jpg|upright=0.70|thumb|left|200px|Uraninite ores have elevated concentrations of actinium. Credit: [[c:user:Robert Matthew Lavinsky|Robert Matthew Lavinsky]].{{tlx|free media}}]]
[[Image:Actinium spectrum visible.png|thumb|center|400px|Actinium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
AcOF, AcOCl, AcOBr exist.
{{clear}}

==Aluminums==
{{main|Chemicals/Aluminums}}
[[Image:Aluminum1.jpg|thumb|right|250px|Near the top center of this image is a gray reflective flake of native aluminum. Credit: Vasil Arnaudov.{{tlx|fairuse}}]]
[[Image:Native aluminum in polished section 2.png|thumb|right|250px|The bright silvery flakes are native aluminum in a polished section. Credit: Thomas Witzke / Abraxas-Verlag.{{tlx|fairuse}}]]
[[Image:Aluminum flame.png|thumb|left|250px|The image shows the color of aluminum in a natural gas burner. Credit: Alternative Fuels Laboratory/McGill University.
{{tlx|fairuse}}]]
[[Image:Aluminium spectrum visible.png|center|thumb|400px|Aluminium spectrum is 400 nm - 700 nm Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
This flake was discovered, "During a field trip to the NW Rila Mountain in the early 1960s, one of us (V.A.) investigated the desilicated pegmatite apophysis and, from the phlogopite zone (Fig. 1c), collected a rock specimen with a protruding metallic flake visible to the naked eye (Fig. 2) [from which the above image was cropped]."<ref name=Dekov>{{ cite journal
|author=Vesselin M. Dekov, Vasil Arnaudov, Frans Munnik, Tanya B. Boycheva, and Saverio Fiore
|title=Native aluminum: Does it exist?
|journal=American Mineralogist
|month=August
|year=2009
|volume=94
|issue=8-9
|pages=1283-6
|url=http://rruff.info/uploads/AM94_1283.pdf
|arxiv=
|bibcode=
|doi=10.2138/am.2009.3236
|pmid=
|accessdate=2015-08-28 }}</ref>

The designation for native aluminum is Al<sup>0</sup> as indicated in, "Here we present data for a unique Al<sup>0</sup> flake protruding from the phlogopite matrix of a rock specimen collected from a desilicated pegmatite vein."<ref name=Dekov/>

Native aluminium metal is extremely rare and can only be found as a minor phase in low oxygen fugacity environments, such as the interiors of certain volcanoes.<ref name=WebmineralAluminums>{{cite web
|title=Aluminum Mineral Data|last1=Barthelmy|first1=D.|website=Mineralogy Database|url=https://web.archive.org/web/20080704001129/http://webmineral.com/data/Aluminum.shtml|archive-date=4 July 2008|accessdate=9 July 2008 }}</ref> Native aluminium has been reported in cold seeps in the northeastern continental slope of the South China Sea, where these deposits may have resulted from bacterial reduction of tetrahydroxoaluminate Al(OH)<sub>4</sub><sup>−</sup>.<ref name="Chen 2011">{{cite journal|last1=Chen|first1=Z.|last2=Huang|first2=Chi-Yue|last3=Zhao|first3=Meixun|last4=Yan|first4=Wen|last5=Chien|first5=Chih-Wei|last6=Chen|first6=Muhong|last7=Yang|first7=Huaping|last8=Machiyama|first8=Hideaki|last9=Lin|first9=Saulwood|date=2011|title=Characteristics and possible origin of native aluminum in cold seep sediments from the northeastern South China Sea|journal=Journal of Asian Earth Sciences|volume=40|issue=1|pages=363–370|bibcode=2011JAESc..40..363C|doi=10.1016/j.jseaes.2010.06.006 }}</ref>

The second image of native aluminum is shown on the right of this section. The sample is from a mud volcano in the Caspian Sea near Baku, Azerbaidzhan.

The type locality for native aluminum is the Tolbachik volcano, Kamchatka, Russia.

'''Def.''' any "intermetallic compound of aluminium and a more electropositive element"<ref name=AluminideWikt>{{ cite book
|title=aluminide
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=31 March 2014
|url=https://en.wiktionary.org/wiki/aluminide
|accessdate=2015-02-22 }}</ref> is called an '''aluminide'''.

The '''aluminides''' are those naturally occurring minerals with a high atomic % aluminum.

In the image on the right of a flake of native aluminum, the scale bar = 1 mm.

The typical alloying elements are copper, magnesium, manganese, silicon, tin and zinc.

Aluminium is the third most abundant element (after oxygen and silicon) in the Earth's crust, and the most abundant metal there. It makes up about 8% by mass of the crust, though it is less common in the mantle below.

As a mineral occurrence, aluminum is mostly an oxide.
{{clear}}

==Americiums==
[[Image:Americium microscope.jpg|thumb|right|250px|A small disc of Am-241 is shown under the microscope. Credit: [[c:user:Bionerd|Bionerd]].{{tlx|free media}}]]
[[Image:Americium spectrum visible.png|thumb|center|400px|Americium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Sorption of americium at trace levels has been detected on a clay mineral.<ref name=Stammose>{{ cite journal
|author=D. Stammose and J.-M. Dolo
|title=Sorption of americium at trace levels on a clay mineral
|journal=Radiochimica Acta
|month=
|year=1990
|volume=51
|issue=
|pages=189-93
|url=https://books.google.com/books?id=AP3wCAAAQBAJ&pg=PA202&lpg=PA202&source=bl&ots=HSbrCjCBzW&sig=TCbSmutAUaFoz9bY4OEShSLPcSw&hl=en&sa=X&ved=0CDsQ6AEwBWoVChMIz8GJ9P_6yAIVRuYmCh24kA0R#v=onepage&f=false
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=2015-11-05 }}</ref>
{{clear}}

==Antimonies==
[[Image:Antimony massive.jpg|thumb|right|200px|This is massive antimony with oxidation products from Arechuybo, Mexico. Credit: [[c:User:Aramgutang|Aram Dulyan]] at the Natural History Museum, London.{{tlx|free media}}]]
[[Image:Antimony-229849.jpg|thumb|left|200px|The native antimony crystals, lustrous and nicely striated in part, range up to 0.5 cm in size. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
[[Image:FlammenfärbungSb.png|thumb|center|100px|The image shows the color of antimony in a natural gas burner. Credit: [[:de:user:Herge|Herge]].{{tlx|free media}}]].
[[Image:Antimony spectrum visible.png|thumb|center|400px|Antimony spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Native antimony such as occurs in the rock on the upper right with its various oxidation products is crystalline in the hexagonal system.

The image on the left shows hexagonal crystals with metallic luster.
{{clear}}

==Argons==
{{main|Chemicals/Argons}}

==Arsenics==
[[Image:Native arsenic from silver vein.jpg|thumb|right|200px|Native arsenic such as this specimen is found in silver ore veins. Credit: Amethyst Galleries, Inc.{{tlx|fairuse}}]]
[[Image:Native arsenic.jpg|thumb|left|200px|This massive native arsenic with quartz and calcite is from Ste. Marie-aux-mines, Alsace, France. Credit: [[c:User:Aramgutang|Aram Dulyan]].{{tlx|free media}}]]
[[Image:Ultrapure metallic arsenic under argon.jpg|right|thumb|250px|Ultrapure metallic arsenic is kept under argon, 1-2 grams. Credit: Hi-Res Images of Chemical Elements.{{tlx|free media}}]]
[[Image:FlammenfärbungAs.jpg|thumb|left|100px|The image shows the color of arsenic in a natural gas burner. Credit: [[:de:user:Herge|Herge]].{{tlx|free media}}]].
[[Image:Arsenic spectrum visible.png|center|thumb|400px|Arsenic emission spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Native arsenic such as in the image on the right occurs in silver ore veins.

"The dominant group V source is arsenic, although antimony and phosphorous sources are not atypical."<ref name=Melloch>{{ cite journal
|author=M. R. Melloch
|author2=J. M. Woodall
|author3=E. S. Harmon
|author4=N. Otsuka
|author5=Fred H. Pollak
|author6=D. D. Nolte
|author7=R. M. Feenstra
|author8=M. A. Lutz
|title=Low-temperature grown III-V materials
|journal=Annual Review of Materials Science
|year=1995
|volume=25
|issue=1
|pages=547-600
|url=http://www.annualreviews.org/doi/pdf/10.1146/annurev.ms.25.080195.002555
|arxiv=
|bibcode=
|doi=10.1146/annurev.ms.25.080195.002555
|pmid=
|accessdate=2013-08-29 }}</ref>
{{clear}}

==Allemontites==
[[Image:Allemontite - USGS Mineral Specimens 008.jpg|thumb|right|200px|Allemontite (with Pen for scale) is from the mineral collection of Brigham Young University Department of Geology, Provo, Utah. Credit: Andrew Silver, USGS.{{tlx|free media}}]]
[[Image:Allemontite-118476.jpg|thumb|left|200px|Allemontite specimen is from Příbram, Central Bohemia Region, Bohemia (Böhmen; Boehmen), Czech Republic. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
Allemontite is a native alloy of arsenic and antimony, with a composition of AsSb.<ref name=Roberts/>

The first example on the right is from the mineral collection of Brigham Young University Department of Geology, Provo, Utah.

The second on the left is from Příbram, Central Bohemia Region, Bohemia (Böhmen; Boehmen), Czech Republic.

As a natural source of arsenic, it has 50 at % arsenic.
{{clear}}

==Astatines==

Astatine iodide has the chemical formula AtI. Astatine bromide has the chemical formula AtBr. Astatine monochloride (AtCl) is made either by the direct combination of gas-phase astatine with chlorine or by the sequential addition of astatine and dichromate ion to an acidic chloride solution.

==Uraninites==
[[Image:Uraninite Astatine source.jpg|thumb|right|250px|The rarest naturally occurring element on Earth is named Astatine and it occurs in uraninite as a uranium decay product. Credit: Fred E. Davis.{{tlx|fairuse}}]]
[[Image:Uraninite crystal cluster.jpg|thumb|left|250px|A cluster of seven crystals, four are visible, in the photo of uraninite, with a yellow uranophane coating. Credit: Fred E. Davis.{{tlx|fairuse}}]]
All of the known isotopes of astatine are very short-lived. Astatine occurs naturally in minerals such as uraninite as a decay product of uranium.
{{clear}}

==Bariums==
[[Image:Barium unter Argon Schutzgas Atmosphäre.jpg|thumb|right|250px|Pure barium metal in a protective argon gas atmosphere. Credit: Matthias Zepper.{{tlx|free media}}]]
[[Image:Barium flame.png|thumb|left|250px|The image shows the color of barium in a natural gas burner. Credit: Ernest Z.
{{tlx|fairuse}}]]
[[Image:Phase diagram of barium (1975).png|thumb|center|250px|This is a pressure-temperature phase diagram for barium. Credit: David A. Young, ERDA.{{tlx|free media}}]]
[[Image:Barium spectrum visible.png|thumb|center|400px|Barium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Barium is bcc (α-Ba) at room temperature as the phase diagram on the left indicates. It does change to an hcp structure at high pressures and temperatures.

Native barium is not known to occur on the surface of the Earth.
{{clear}}

==Berkeliums==
[[Image:Gabon Geology Oklo.svg|right|thumb|200px|The geological situation in Gabon leading to natural nuclear fission reactors is described<br>1. Nuclear reactor zones<br>2. Sandstone<br>3. Uranium ore layer<br>4. Granite. Credit: [[c:User:MesserWoland|MesserWoland]].{{tlx|free media}}]]
[[Image:Berkelium spectrum visible.png|thumb|center|400px|Berkelium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Like americium and curium it "is possible that some berkelium and other transuranic elements were created in the natural nuclear reactor in Oklo, Gabon."<ref name=jolyonBk>{{ cite web
|author=jolyon
|title=The Mineralogy of Curium
|publisher=Hudson Institute of Mineralogy
|location=
|date=6 November 2015
|url=http://www.mindat.org/element/Berkelium
|accessdate=2015-11-05 }}</ref>

A '''natural nuclear fission reactor''' is a uranium mineral deposit where self-sustaining [[w:nuclear chain reaction|nuclear chain reaction]]s have occurred. This can be examined by analysis of isotope ratios. The existence of this phenomenon was discovered in 1972 at Oklo in Gabon, Africa. Oklo is the only known location for this in the world and consists of 16 sites at which self-sustaining nuclear fission reactions took place approximately 1.7 billion years ago, and ran for a few hundred thousand years, averaging 100 kW of thermal power during that time.<ref name=Meshik>{{ cite journal
|author=A. P. Meshik
|year=2005
|month=November
|title=The Workings of an Ancient Nuclear Reactor
|journal=Scientific American
|volume=
|issue=
|pages=
|url=http://www.sciam.com/article.cfm?id=ancient-nuclear-reactor
|accessdate= }}</ref><ref name="Gauthier-Lafaye1996">{{ cite journal
|author=F. Gauthier-Lafaye; P. Holliger; P.-L. Blanc
|year=1996
|month=
|title=Natural fission reactors in the Franceville Basin, Gabon: a review of the conditions and results of a "critical event" in a geologic system
|journal=Geochimica et Cosmochimica Acta
|volume=60
|issue=25
|pages=4831–52
|doi=10.1016/S0016-7037(96)00245-1
|url=
|bibcode=1996GeCoA..60.4831G }}</ref>
{{clear}}

==Berylliums==
{{main|Chemicals/Berylliums}}
[[Image:Beryllium emission spectrum.png|thumb|center|400px|This spectrograph shows the visual spectral lines of beryllium. Credit: [[c:User:Penyulap|Penyulap]].{{tlx|free media}}]]
[[Image:Be-140g.jpg|thumb|right|Beryllium is > 99 % pure, crystalline big fragment > 140 g. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Beryllium-Chromium phase diagram.png|thumb|left|250px|This is a beryllium-chromium phase diagram. Credit: M. Venkatraman and J.P. Neumann.{{tlx|fairuse}}]]
Beryllium has at least six emission/absorption lines across the red.

The emission and absorption spectra for beryllium contain lines in the blue.

Beryllium occurs in a hexgonal close-packed (hcp) crystal structure at room temperature (α-Be).

As indicated in the phase diagram on the left beryllium occurs as (β-Be) which is bcc at higher temperatures up to melting.

Native beryllium is not known to occur on the surface of the Earth, but may eventually be found among beryllium-bearing minerals in small amounts.

Beryllium copper (BeCu), also known as copper beryllium (CuBe), beryllium bronze and spring copper, is a copper alloy with 0.5–3% beryllium,<ref>http://www.matthey.ch/index.php?id=45&L=1 Copper beryllium and nickel beryllium datasheets.</ref> but can contain other elements as well. Beryllium can be alloyed with nickel and aluminum.<ref>{{Cite web
  |title=Beralcast – Beryllium Aluminum Alloys
  |website=IBC Advanced Alloys
  |accessdate=2015-07-22
|url=https://web.archive.org/web/20150723034608/http://www.ibcadvancedalloys.com/products/beryllium-aluminum-alloys-beralcast-alloys/
  |archive-date=2015-07-23 }}</ref>
{{clear}}

==Bismuths==
[[Image:Bismuth-113484.jpg|right|thumb|250px|A rich small mini of the native element bismuth is from from China. Credit: Robert M. Lavinsky.{{tlx|free media}}]]
[[Image:Bismuth spectrum visible.png|thumb|center|400px|Bismuth spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Bismuth does occur on Earth as native bismuth exampled on the right.

"Strong absorption lines due to Bi II have been found in the Hg—Mn star HR7775 (HD193452) in high-resolution spectra obtained with the IUE."<ref name=Jacobs>{{ cite journal
|author=J. M. Jacobs & M. M. Dworetsky
|title=Bismuth abundance anomaly in a Hg—Mn star
|journal=Nature
|date=7 October 1982
|volume=299
|issue=
|pages=535–536
|url=https://www.nature.com/articles/299535a0
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=20 June 2022 }}</ref>

"Detailed examination of the optical spectrum at high resolution<sup>1</sup> showed that it is one of the most extreme stars of the ‘cool’ Hg—Mn group, with strong enhancements of Hg, Pt, Sr, Y, and Ga; the last of these is confirmed<sup>2</sup> by the very strong Ga II resonance line at 1,414 Å. Four-colour Strömgren photometry of HR7775 (ref. 3), interpreted with the aid of the model atmosphere calibrations by Relyea and Kurucz<sup>4</sup>, gives T<sub>eff</sub> = 10,800 K, log g = 4.2, while the Hβ index gives log g = 4.0 according to the calibration of Schmidt<sup>5</sup>."<ref name=Jacobs/>
{{clear}}

==Bohriums==

Chemistry experiments have confirmed that bohrium behaves as the heavier homologue to rhenium in group 7. The chemical properties of bohrium are characterized only partly, but they compare well with the chemistry of the other group 7 elements.

==Borons==
{{main|Chemicals/Borons}}
[[Image:Boron R105.jpg|thumb|right|250px|These polycrystalline chunks are rhombohedral β-boron, net 25.5 grams. Credit: James L Marshall.{{tlx|free media}}]]
[[Image:Boron phase diagram.svg|thumb|left|250px|Phase diagram is elemental boron (colors represent actuals). Credit: [[c:user:Fulvio314|Fulvio314]].{{tlx|free media}}]]
[[Image:Boron emission spectrum.png|thumb|center|400px|This spectrograph shows the visual spectral lines of boron. Credit: [[c:User:Penyulap|Penyulap]].{{tlx|free media}}]]
[[Image:Boron (B).jpg|thumb|right|250px|Crystalline boron, which is shown here, is nearly as hard as diamond (9.5 on Mohs scale, diamond has 10). Credit: Hi-Res Images of Chemical Elements.{{tlx|free media}}]]
[[Image:FlammenfärbungB.png|thumb|left|100px|The image shows the color of boron in a natural gas burner. Credit: [[:de:user:Herge|Herge]].{{tlx|free media}}]].
Boron is synthesized entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, so it is a low-abundance element in the Solar System and in the Earth's crust.<ref>{{cite web
|title = Q & A: Where does the element Boron come from?
|accessdate = 2011-12-04
|url = https://web.archive.org/web/20120529072641/http://van.physics.illinois.edu/qa/listing.php?id=17594|archive-date = 29 May 2012 }}</ref> It constitutes about 0.001 percent by weight of Earth's crust.<ref>{{cite web
|title=Boron|website=Britannica encyclopedia|accessdate=4 August 2020|archive-date=4 August 2020|url=https://web.archive.org/web/20200804181151/https://www.britannica.com/science/boron-chemical-element }}</ref> It is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate mineral such as borax and kernite.

Elemental boron is a metalloid that is found in small amounts in meteoroids but chemically uncombined boron is not otherwise found naturally on Earth.

The "presence in ... cosmic radiation [is] of a much greater proportion of "secondary" nuclei, such as lithium, beryllium and boron, than is found generally in the universe."<ref name="Gaisser">{{cite book
|author=Thomas K. Gaisser
|title=Cosmic Rays and Particle Physics
|publisher=Cambridge University Press
|location=
|date=1990
|editor=
|pages=279
|url=http://books.google.com/books?hl=en&lr=&id=qJ7Z6oIMqeUC&oi=fnd&pg=PR15&ots=IxjwLxBwXu&sig=voHKIYstBlBYla4jcbur_b-Zwxs
|arxiv=
|bibcode=
|doi=
|pmid=
|{{isbn=0521339316}}
|accessdate=2014-01-11 }}</ref>
{{clear}}

==Qingsongites==

Qingsongite is a rare boron nitride (BN) mineral with cubic crystalline form first described in 2009 for an occurrence as minute inclusions within chromite deposits in the Luobusa ophiolite in the Shannan Prefecture, Tibet Autonomous Region, China.<ref name=MindatQingsongite1977/> It was recognized as a mineral in August 2013 by the International Mineralogical Association named after Chinese geologist Qingsong Fang (1939–2010).<ref name=MindatQingsongite1977>[http://www.mindat.org/min-43792.html Qingsongite on Mindat.org]</ref> 

Qingsongite is the only known boron mineral that is formed deep in the Earth's mantle.<ref>[http://www.sci-news.com/geology/science-qingsongite-new-mineral-01286.html Qingsongite: New Mineral from Tibet Hard as Diamond]. sciencenews.org. August 5, 2013</ref> Associated minerals or phases include osbornite (titanium nitride), coesite, kyanite and amorphous carbon.<ref name=Pittalwala>[http://ucrtoday.ucr.edu/16729  Pittalwala, Iqbal, ''International Research Team Discovers New Mineral,'' UCR Today, Aug. 2, 2013]</ref>

==Wurtzite BN==

Only small amounts of the wurtzite form of boron nitride (w-BN) exist in nature as a mineral.<ref name=Griggs>{{Cite web |url=https://www.newscientist.com/article/dn16610-diamond-no-longer-natures-hardest-material/ |title=Diamond no longer nature's hardest material |last=Griggs |first=Jessica |date=2014-05-13 |website=New Scientist |accessdate=2018-01-12}}</ref>

==Bromines==
{{main|Chemicals/Bromines}}

==Cadmiums==
[[Image:CadmiumMetalUSGOV.jpg|thumb|right|250px|Cadmium metal bowl is shown. Credit: [[c:user:Halfdan|Halfdan]].{{tlx|free media}}]]
[[Image:Cadmium-crystal bar.jpg|thumb|left|250px|A crystal cadmium bar, purity 99.999 %, made by the flux process, as well as a 1 cm<sup>3</sup> cadmium cube for comparison. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Cadmium spectrum visible.png|thumb|center|400px|Cadmium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The only cadmium mineral of importance, greenockite (CdS), is nearly always associated with sphalerite (ZnS).

Cadmium is used in the control rods of nuclear reactors, acting as a very effective neutron poison to control neutron flux in nuclear fission.<ref name=Scoullos>{{cite book|url = https://books.google.com/books?id=9yzN-QGag_8C|title = Mercury, Cadmium, Lead: Handbook for Sustainable Heavy Metals Policy and Regulation|first1 = Michael J.|last1 = Scoullos|last2= Vonkeman|first2=Gerrit H.|last3 = Thornton|first3=Iain|last4 = Makuch |first4=Zen| publisher = Springer|date = 2001|{{isbn|978-1-4020-0224-3}} }}</ref> When cadmium rods are inserted in the core of a nuclear reactor, cadmium absorbs neutrons, preventing them from creating additional fission events, thus controlling the amount of reactivity. The pressurized water reactor designed by Westinghouse Electric Company uses an alloy consisting of 80% silver, 15% indium, and 5% cadmium.<ref name=Scoullos/>

In Polyvinyl chloride (PVC), cadmium was used as heat, light, and weathering stabilizers.<ref name=Scoullos/><ref name=Jennings>{{cite book|url = https://books.google.com/books?id=YUkJNI9QYsUC&pg=PA149|page = 149|first = Thomas C.|last = Jennings|{{isbn|978-1-56990-379-7}}| publisher = Hanser Verlag|date = 2005|title = PVC handbook|chapter = Cadmium Environmental Concerns}}</ref> Cadmium is used in many kinds of solder and bearing alloys, because it has a low coefficient of friction and fatigue resistance.<ref name=Scoullos/> It is also found in some of the lowest-melting alloys, such as Wood's metal.<ref name=Brady>{{cite book|first1= George Stuart|last1= Brady|first2= George S.|last2= Brady|first3= Henry R.|last3= Clauser|first4 = John A.|last4 = Vaccari|isbn = 978-0-07-136076-0|url = https://books.google.com/books?id=vIhvSQLhhMEC&pg=PA425|title = Materials handbook: an encyclopedia for managers, technical professionals, purchasing and production managers, technicians, and supervisors|publisher = McGraw-Hill Professional|date = 2002| page = 425}}</ref>
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==Caesiums==
[[Image:CsCrystals.JPG|thumb|right|250px|High pure cesium crystals show dendritic morphology. Credit: [[c:user:Dnn87|Dnn87]].{{tlx|free media}}]]
[[Image:Phase diagram of cesium (1975).png|thumb|left|250px|Temperature-pressure diagram for caesium, formerly known as "cesium". Credit: David A. Young, ERDA.{{tlx|free media}}]]
[[Image:Caesium flame.png|thumb|center|250px|The image shows the color of caesium in a natural gas burner. Credit: Ernest Z.
{{tlx|fairuse}}]]
[[Image:Caesium spectrum visible.png|thumb|center|400px|Caesium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
As the temperature-pressure diagram on the left shows, caesium (formerly cesium) is bcc (α-Cs) from room temperature up to melting.

Native caesium does not appear to occur on the surface of the Earth or the Moon.
{{clear}}

==Calciums==
[[Image:Calcium unter Argon Schutzgasatmosphäre.jpg|thumb|right|250px|Pure calcium metal is shown in a protective argon atmosphere. Credit: Matthias Zepper.{{tlx|free media}}]]
[[Image:Calcium spectrum visible.png|thumb|center|400px|Calcium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:FlammenfärbungCa.png|thumb|left|100px|The image shows the color of calcium in a natural gas burner. Credit: [[:de:user:Herge|Herge]].{{tlx|free media}}]].
[[Image:Calcium Spectrum.jpg|thumb|center|400px|Spectrum of Ca is at 600/pmm. Credit: [[w:user:teravolt|teravolt]].{{tlx|free media}}]]
[[Image:Aluminum-Calcium phase diagram.png|thumb|right|250px|This is an Aluminum-Calcium phase diagram. Credit: The ESA IMPRESS Team.{{tlx|fairuse}}]]
Calcium has a face-centered cubic (fcc) crystal structure at room temperature.

As shown in the phase diagram on the left, it does not change structure up to melting.

Native calcium is not known to occur on the surface of the Earth.
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==Californiums==
[[Image:Californium.jpg|thumb|right|250px|A disc of californium metal (<sup>249</sup>Cf, 10 mg). Credit: United States Department of Energy.{{tlx|free media}}]]
[[Image:Californium spectrum visible.png|thumb|center|400px|Californium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
It forms alloys with lanthanide metals.<ref name=Haire>Haire, Richard G. (2006). "Californium". In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Springer Science+Business Media. {{ISBN|978-1-4020-3555-5}}.</ref>

The element has two crystalline forms at standard atmospheric pressure: a double-hexagonal close-packed form dubbed alpha (α) and a face-centered cubic form designated beta (β). A double hexagonal close-packed (dhcp) unit cell consists of two hexagonal close-packed structures that share a common hexagonal plane, giving dhcp an ABACABAC sequence.<ref>Szwacki, Nevill Gonzalez; Szwacka, Teresa (2010). Basic Elements of Crystallography. Pan Stanford. {{ISBN|978-981-4241-59-5}}.</ref> The α form exists below 600–800&nbsp;°C with a density of 15.10&nbsp;g/cm<sup>3</sup> and the β form exists above 600–800&nbsp;°C with a density of 8.74&nbsp;g/cm<sup>3</sup>.<ref name=Haire/> At 48&nbsp;GPascal of pressure the β form changes into an orthorhombic crystal system due to delocalization of the atom's 5f electrons, which frees them to bond.<ref name=Haire/> The three lower-mass transplutonium elements—americium, curium, and berkelium—require much less pressure to delocalize their 5f electrons.<ref name=Haire/>
{{clear}}

==Carbons==
{{main|Chemicals/Carbons}}
[[Image:Carbon Spectra.jpg|thumb|center|400px|The spectrum shows the lines in the visible due to emission from elemental carbon. Credit:[[w:User:Teravolt|Teravolt]].{{tlx|free media}}]]
[[Image:Bunsen burner flame types.png|thumb|left|50px|The image shows the color of carbon in a natural gas burner. Credit: Arthur Jan Fijałkowski.
{{tlx|free media}}]].
[[Image:Graphite-and-diamond-with-scale.jpg|right|thumb|300px|Diamond and graphite are shown side by side, where the scale is based on a rough approximation. Credit: Robert Lavinsky.{{tlx|free media}}]]
Carbonides are naturally occurring minerals composed of 50 atomic percent, or more, carbon. Carbonide-like minerals with greater than 25 at % carbon are also included. This separates carbon containing minerals from carbonates which are at most 25 at % carbon.

Carbon has an emission line in plasmas at 529.053 nm from C VI.<ref name=McCarthy>{{ cite book
|author=K. J. McCarthy
|author2=A. Baciero
|author3=B. Zurro
|author4=TJ-II Team
|title=Impurity Behaviour Studies in the TJ-II Stellarator, In: ''27th EPS Conference on Contr. Fusion and Plasma Phys.''
|publisher=ECA
|location=Budapest
|date=12 June 2000
|volume=24B
|editor=
|pages=1244-7
|url=http://crpppc42.epfl.ch/Buda/pdf/p3_116.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|isbn=
|accessdate=20 January 2013 }}</ref>
{{clear}}

==Ceriums==
[[Image:Cerium2.jpg|thumb|right|250px|Ultrapure Cerium metal is shown under argon, 1.5 grams. Credit: [[c:user:Jurii|Jurii]].{{tlx|free media}}]]
[[Image:Cerium spectrum visible.png|thumb|center|400px|Cerium spectrum is shown for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The pyrophoric alloy known as "mischmetal" is composed of 50% cerium, 25% lanthanum, and the remainder being the other lanthanides, that is used widely for lighter flints.<ref name=Greenwood>Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. {{ISBN|978-0-08-037941-8}}.</ref> Usually iron is added to form the alloy ferrocerium (a synthetic pyrophoric alloy of "mischmetal": cerium, lanthanum, neodymium, other trace lanthanides and some iron – about 95% lanthanides and 5% iron hardened by blending in oxides of iron and / or magnesium).<ref name=Ullmann>Klaus Reinhardt and Herwig Winkler in "Cerium Mischmetal, Cerium Alloys, and Cerium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2000, Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a06_139}}</ref>

Cerium is used as alloying element in aluminum to create castable eutectic aluminum alloys with 6–16 wt.% Ce, to which Mg and/or Si can be further added, which have excellent high temperature strength and are suitable for automotive applications ''e.g.'' in cylinder heads.<ref name=Sims>{{Cite journal|last=Sims|first=Zachary|date=2016|title=Cerium-Based, Intermetallic-Strengthened Aluminum Casting Alloy: High-Volume Co-product Development|journal=JOM |volume=68|issue=7|pages=1940–1947|bibcode=2016JOM....68g1940S|doi=10.1007/s11837-016-1943-9|osti=1346625|s2cid=138835874|url=https://www.osti.gov/biblio/1257369}}</ref> Other alloys of cerium include Pu-Ce and Pu-Ce-Co plutonium alloys, which have been used as nuclear fuel.
{{clear}}

==Chlorines==
{{main|Chemicals/Chlorines}}

==Chromiums==
[[Image:Native chromium.jpg|thumb|right|200px|This is a native chromium nugget. Credit: Neal Ekengren.{{tlx|fairuse}}]]
[[Image:Fe-Cr Phase Diagram.gif|thumb|left|250px|Fe-Cr phase diagram shows which phases are to be expected at equilibrium for different combinations of chromium content and temperature. Credit: Computational Thermodynamics Inc.{{tlx|fairuse}}]]
[[Image:Chromium2.jpg|right|thumb|300px|A hunk of chromium metal is shown. Credit: W. Oelen.{{tlx|free media}}]]
[[Image:ChromiumFlameTestOxyHydrogen.png|thumb|left|150px|The image shows the color of chromium in an oxy-hydrogen torch. Credit: [[c:user:NSEasternShoreChemist|NSEasternShoreChemist]].{{tlx|free media}}]].
[[Image:Chromium spectrum visible.png|thumb|center|400px|This is a visible emission-line spectrum for chromium over the range: 400-700 nm. Credit: [[c:User:McZusatz|McZusatz]].{{tlx|free media}}]]
Native chromium such as the nugget in the image on the right is very rare. It is also a hard mineral, probably because of an oxide coating giving it a slight bluish cast.

"An unusual mineral association (diamond, SiC, graphite, native chromium, Ni-Fe alloy, Cr<sup>2+</sup>-bearing chromite), indicating a high-pressure, reducing environment, occurs in both the peridotites and chromitites."<ref name=Bai>{{ cite journal
|author=Wen-Ji Bai, Mei-Fu Zhou, and Paul T. Robinson
|title=Possibly diamond-bearing mantle peridotites and podiform chromitites in the Luobusa and Donqiao ophiolites, Tibet
|journal=Canadian Journal of Earth Sciences
|month=August
|year=1993
|volume=30
|issue=8
|pages=1650-9
|url=http://www.nrcresearchpress.com/doi/abs/10.1139/e93-143
|arxiv=
|bibcode=
|doi=10.1139/e93-143
|pmid=
|accessdate=2015-08-19 }}</ref>

As the phase diagram for the Fe-Cr system on the left shows, chromium is bcc from 600°C on up to melting. Chromium is also bcc at room temperature and pressure.
{{clear}}

==Cobalts==
[[Image:Native cobalt from Moon.jpg|thumb|right|250px|This is a scanning electron micrograph of native cobalt from the Luna 24 landing site, Mare Crisium, The Moon. Credit: Pavel M. Kartashov, Hudson Institute of Mineralogy.{{tlx|fairuse}}]]
[[Image:Kobalt electrolytic and 1cm3 cube.jpg|thumb|left|250px|Pure (99.9 %) cobalt chips, electrolytically refined, and a high purity (99.8 % = 2N8) 1 cm<sup>3</sup> cobalt cube for comparison is shown. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:CobaltFlameTestOxyHydrogen.png|thumb|left|150px|The image shows the color of cobalt in an oxy-hydrogen torch. Credit: [[c:user:NSEasternShoreChemist|NSEasternShoreChemist]].{{tlx|free media}}]].
[[Image:Cobalt spectrum visible.png|center|thumb|400px|Cobalt emission spectrum is from 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Cobalt has a hexagonal close-packed structure (hcp) until about 450°C when a fcc structure begins to appear.

On the right is a scanning electron micrograph of native cobalt from the Luna 24 landing site, Mare Crisium, The Moon.
{{clear}}

==Coperniciums==

Very few properties of copernicium or its compounds have been measured; this is due to its extremely limited and expensive production<ref name=Subramanian>{{Cite web|url=https://www.bloomberg.com/news/features/2019-08-28/making-new-elements-doesn-t-pay-just-ask-this-berkeley-scientist|title=Making New Elements Doesn't Pay. Just Ask This Berkeley Scientist|last=Subramanian|first=S.|website=Bloomberg Businessweek|accessdate=2020-01-18}}</ref> and the fact that copernicium (and its parents) decays very quickly.

==Coppers==
[[Image:Copper-114517.jpg|thumb|right|250px|A large, sculptural specimen of penny-bright copper is from Arizona. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
[[Image:Copper spectrum visible.png|center|thumb|400px|Copper emission spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Landsat Thematic Mapper Manitouwadge.jpg|thumb|left|250px|This is a Landsat Thematic Mapper image with overlain geological structures. Credit: I.M. Kettles, A.N. Rencz, and S.D. Bauke.{{tlx|fairuse}}]]
[[Image:Copper (I) blue flame.png|thumb|left|50px|The image shows the color of copper (I) in a natural gas burner. Credit: Anne Marie Helmenstine.
{{tlx|fairuse}}]]
[[Image:Flametest--Cu.swn.jpg|thumb|right|100px|The image shows the color of copper (II) non-halide in a natural gas burner. Credit: [[c:user:Søren Wedel Nielsen|Søren Wedel Nielsen]].{{tlx|free media}}]].
[[Image:Cu+2 (CuCl2)-Blue.jpg|thumb|center|100px|The image shows the color of copper (II) halide in a natural gas burner. Credit: AmazingRust.
{{tlx|fairuse}}]]
The most advantageous form for copper is native copper.

On the right is a large, sculptural specimen of penny-bright copper from Arizona.

"Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion."<ref name=Johnson>{{ cite journal
|author=A.B. Johnson Jr.
|author2=B. Francis
|title=Durability of metals from archaeological objects, metal meteorites, and native metals
|publisher=Battelle Pacific Northwest Laboratories, Department of Energy
|location=Richland, Washington USA
|month=1 January
|year=1980
|editor=
|volume=PNL-3198
|issue=TRN: 80-007629
|pages=
|url=http://www.osti.gov/scitech/biblio/5406419
|arxiv=
|bibcode=
|doi=10.2172/5406419
|pmid=
|accessdate=2014-10-28 }}</ref>

"A group of pixel areas north of Lake Superior [in the Landsat image on the right] take the form of a linear band which lies along the northern edge of the Port Coldwell Complex (D). [...] there are numerous Cu showings along the northern edge of the Port Coldwell complex (Ontario Division of Mines, 1971)."<ref name=Kettles>{{ cite journal
|author=I.M. Kettles
|author2=A.N. Rencz
|author3=S.D. Bauke
|title=Integrating Landsat, Geologic, and Airborne Gamma Ray Data as an Aid to Surficial Geology Mapping and Mineral Exploration in the Manitouwadge Area, Ontario
|journal=Photogrammetric Engineering & Remote Sensing
|month=April
|year=2000
|volume=66
|issue=4
|pages=437-45
|url=http://asprs.org/a/publications/pers/2000journal/april/2000_apr_437-445.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=2014-10-28 }}</ref>

{| class="wikitable"
|+Classification of copper and its alloys
|-
!Family!!Principal alloying element!!Composition range wt %!!Other elements
|-
|Copper alloys, brass||Zinc (Zn)||30% Zn||0.02–0.15% As, 1.7–2.8% Pb, P, Al, Mn, 0.05% iron, and Si
|-
|Phosphor bronze||Tin (Sn)||0.5–11% Sn, 0.01–0.35% P||0.5–3.0% Pb
|-
|Aluminium bronzes||Aluminium (Al)||5% to 11% aluminium||iron, nickel, manganese, zinc, silicon, arsenic
|-
|Silicon bronzes||Silicon (Si)||<6%Si, 92.5% Cu-7.5% Si||Al, Zn, Ti, Fe
|-
|Cupronickel, nickel silvers||Nickel (Ni)||60-90% Cu, 9-32% Ni, ≥52% Ni (Monel)||0.4-2.3% Fe, 1-2.5% Mn
|}
{{clear}}

==Curiums==
[[Image:Curium spectrum visible.png|thumb|center|400px|Curium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
"Curium is a radioactive transuranic element that has only been produced in nuclear reactors. It is possible that some curium and other transuranic elements were created in the natural nuclear reactor in Oklo, Gabon."<ref name=jolyon>{{ cite web
|author=jolyon
|title=The Mineralogy of Curium
|publisher=Hudson Institute of Mineralogy
|location=
|date=6 November 2015
|url=http://www.mindat.org/element/Curium
|accessdate=2015-11-05 }}</ref>

==Darmstadiums==

The only known darmstadtium isotope with a half-life long enough for chemical research is <sup>281</sup>Ds, which would have to be produced as the granddaughter of <sup>289</sup>Fl.<ref name="Moody">{{cite book |chapter=Synthesis of Superheavy Elements |last1=Moody |first1=Ken |editor1-first=Matthias |editor1-last=Schädel |editor2-first=Dawn |editor2-last=Shaughnessy |title=The Chemistry of Superheavy Elements |publisher=Springer Science & Business Media |edition=2nd |pages=24–8 |isbn=9783642374661|date=2013-11-30 }}</ref>

==Dubniums==

Dubnium was processed in nitric and hydrofluoric acid solution, at concentrations where niobium forms {{chem|NbOF|4|-}} and tantalum forms {{chem|TaF|6|-}}, where dubnium's behavior was close to that of niobium but not tantalum; it was thus deduced that dubnium formed {{chem|DbOF|4|-}}, it was concluded that dubnium often behaved like niobium, sometimes like protactinium, but rarely like tantalum.<ref name=Nagame>{{Cite journal |last1=Nagame |first1=Y.|last2=Kratz |first2=J. V. |last3=Schädel |first3=M.|date=2016 |title=Chemical properties of rutherfordium (Rf) and dubnium (Db) in the aqueous phase|journal=EPJ Web of Conferences|volume=131|doi=10.1051/epjconf/201613107007|page=07007|bibcode=2016EPJWC.13107007N|url=https://jopss.jaea.go.jp/pdfdata/BB2016-0022.pdf|doi-access=free}}</ref>

==Dysprosiums==
[[Image:Dy chips.jpg|thumb|right|250px|Dysprosium metal chips are shown. Credit: [[c:User:Materialscientist|Materialscientist]].{{tlx|free media}}]]
[[Image:Dysprosium spectrum visible.png|thumb|center|400px|Dysprosium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Dysprosium spectrum.png|thumb|center|400px|First order and partial second order spectra of a 12V dysprosium spark taken with a diffraction grating and a cellphone camera. Credit: [[c:user:Umop503|Umop503]].{{tlx|free media}}]]
"The magnetic and structural properties of the neodymium-dysprosium alloy system have 
been measured over the entire composition range."<ref name=Chatterjee>{{ cite journal
|author=D Chatterjee and K N R Taylor
|title=Magnetic and structural properties of the neodymium-dysprosium alloy system
|journal=Journal of Physics F: Metal Physics
|date=1972
|volume=2
|issue=1
|pages=151
|url=https://iopscience.iop.org/article/10.1088/0305-4608/2/1/020/pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=18 June 2022 }}</ref>
{{clear}}

==Einsteiniums==
[[Image:Einsteinium.jpg|thumb|right|250px|Quartz vial (9 mm diameter) contains ~300 micrograms of Es-253 solid. Credit: [http://www.ornl.gov/info/awards/cf/cfcitations/cfbios/haire.shtm Haire, R. G., US Department of Energy].{{tlx|free media}}]]
[[Image:Einsteinium spectrum visible.png|thumb|center|400px|Einsteinium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Einsteinium is a soft, silvery, paramagnetic metal with chemistry typical of the late actinides, with a preponderance of the +3 oxidation state; the +2 oxidation state is also accessible, especially in solids.
{{clear}}

==Erbiums==
[[Image:Erbium-crop.jpg|thumb|right|250px|Erbium is a silvery-white solid metal. Credit: [[:de:User:Tomihahndorf|Tomihahndorf]].{{tlx|free media}}]]
[[Image:Erbium spectrum visible.png|thumb|center|400px|Erbium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Erbium spectrum.png|thumb|center|400px|12V spark spectrum of erbium taken through a diffraction grating with a cellphone camera. Credit: [[c:user:Umop503|Umop503]].{{tlx|free media}}]]
When added to vanadium as an alloy, erbium lowers hardness and improves workability.<ref name=Hammond>{{cite book| last= Hammond |first= C. R. |title = The Elements, in Handbook of Chemistry and Physics |edition = 81st| publisher =CRC press| date = 2000| {{isbn|978-0-8493-0481-1}} }}</ref> An erbium-nickel alloy Er<sub>3</sub>Ni has an unusually high specific heat capacity at liquid-helium temperatures.

"Along with uranium, zinc, iron ore, copper and gold, Greenland’s ancient rocks also harbor large quantities of those minerals known as “rare earth,” among them lanthanum, cerium, neodymium, praesodymium, terbium and yttrium."<ref name=Weiden/>
{{clear}}

==Europiums==
[[Image:Europium.jpg|thumb|right|250px|Weakly oxidized europium, hence slightly yellowish, 1.5 grams, large piece 0.6 x 1.6 cm are shown. Credit: [[c:user:Jurii|Jurii]].{{tlx|free media}}]]
[[Image:Europium spectrum visible.png|thumb|center|400px|Europium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Europium Emission Spectrum.png|thumb|center|400px|Spark spectrum of europium metal taken using a 12V circuit, diffraction grating, and phone camera. Note this is the spectrum of the pure element, not the spectrum it makes as a dopant in phosphors. Credit: [[c:user:Umop503|Umop503]].{{tlx|free media}}]]
The "aluminum−boron−europium ternary alloy fuels with boron content of 1.5∼4.85 
wt. % and europium content of 3 wt. % were prepared."<ref name=Wang>{{ cite journal
|author=Wei Wang, Hui Zou, Shuizhou Cai
|title=The Oxidation and Combustion Properties of Gas Atomized Aluminum− Boron− Europium Alloy Powders
|journal=Propellants, Explosives, Pyrotechnics
|date=18 February 2019
|volume=44
|issue=6
|pages=725-732
|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/prep.201800223
|arxiv=
|bibcode=
|doi=10.1002/prep.201800223
|pmid=
|accessdate=18 June 2022 }}</ref>
{{clear}}

==Fermiums==
[[Image:Fermium-Ytterbium Alloy.jpg|thumb|250px|right|A fermium-ytterbium alloy is used for measuring the enthalpy of vaporization of fermium metal. Credit: Ben E. Lewis.{{tlx|free media}}]]
In the image at the right a fermium-ytterbium alloy is shown.
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==Flevoriums==

About 90 flerovium atoms have been seen: 58 were synthesized directly; the rest were from radioactive decay of heavier elements.

==Fluorines==
{{main|Chemicals/Fluorines}}

==Franciums==
[[Image:Francium-87.jpg|thumb|right|250px|This rock probably contains on the order of a few atoms of francium at any one time, as part of the complex decay chains of the thorium and uranium that make up a much larger fraction of the sample. Credit: Theodore Gray.{{tlx|free media}}]]
[[Image:Pichblende.jpg|thumb|left|250px|This sample of uraninite contains about 100,000 atoms (3.3{{e|-20}}&nbsp;g) of francium-223 at any given time.<ref name=Emsley2001/> Credit: [[c:user:Farhan|Farhan]].{{tlx|free media}}]]
Francium is bcc at room temperature. Outside the laboratory, francium is extremely rare, with trace amounts found in uranium and thorium ores, where the isotope francium-223 continually forms and decays.

Francium chloride has been studied as a pathway to separate francium from other elements, by using the high vapour pressure of the compound, although francium fluoride would have a higher vapour pressure.<ref name=Lavrukhina>Lavrukhina, Avgusta Konstantinovna; Pozdnyakov, Aleksandr Aleksandrovich (1970). Analytical Chemistry of Technetium, Promethium, Astatine, and Francium. Translated by R. Kondor. Ann Arbor–Humphrey Science Publishers. p. 269. {{ISBN|978-0-250-39923-9}}.</ref>
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==Gadoliniums==
[[Image:Gadolinium-4.jpg|thumb|right|250px|Gadolinium is a silvery-white metal when oxidation is removed. Credit: Unknown author.{{tlx|free media}}]]
[[Image:Gadolinium spectrum visible.png|thumb|center|400px|Gadolinium is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Gadolinium spectrum.png|thumb|center|400px|Spectrum of gadolinium from a 12V spark, taken through a diffraction grating with a cellphone camera. The full first order spectrum is visible, and most of the second order; a spectrum of a reflection is also visible, showing the unusual color combination this element emits. Credit: [[c:user:Umop503|Umop503]].{{tlx|free media}}]]
Gadolinium metal is only slightly malleable and is a ductile rare-earth element.

Gadolinium demonstrates a magnetocaloric effect whereby its temperature increases when it enters a magnetic field and decreases when it leaves the magnetic field. The temperature is lowered to {{convert|5|C}} for the gadolinium alloy Gd<sub>85</sub>Er<sub>15</sub>, and this effect is considerably stronger for the alloy Gd<sub>5</sub>(Si<sub>2</sub>Ge<sub>2</sub>), but at a much lower temperature (<{{convert|85|K}}).<ref>{{cite web|author= Gschneidner, Karl Jr |author2= Gibson, Kerry |title= Magnetic refrigerator successfully tested |publisher= Ames Laboratory|date= 7 December 2001|accessdate= 17 December 2006|url=https://web.archive.org/web/20100323011159/http://www.external.ameslab.gov/news/release/01magneticrefrig.htm|archive-date=23 March 2010}}</ref> A significant magnetocaloric effect is observed at higher temperatures, up to about 300&nbsp;K, in the compounds Gd<sub>5</sub>(Si<sub>''x''</sub>Ge<sub>1−''x''</sub>)<sub>4</sub>.<ref name=Gschneidner2001>{{cite journal|author=Gschneidner, K. |author2=Pecharsky, V. |author3=Tsokol, A. |doi=10.1088/0034-4885/68/6/R04 |title=Recent Developments in Magnetocaloric Materials |date=2005 |journal=Reports on Progress in Physics |volume=68 |issue=6 |pages=1479 |bibcode=2005RPPh...68.1479G |url=https://web.archive.org/web/20141109081936/http://www.teknik.uu.se/ftf/education/magnetmatr/Projektreferenser/MCE_Reports_Progress05.pdf }}</ref>
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==Galliums==
[[Image:Gallite from Namibia.jpg|thumb|right|200px|This is an example of gallite from Namibia. Credit: Hudson Institute of Mineralogy.{{tlx|fairuse}}]]
[[Image:Ga,31.jpg|thumb|right|250px|This is a liquid drop of gallium. Credit: [[w:User:RTC|RTC]].{{tlx|free media}}]]
[[Image:Solid gallium (Ga).jpg|left|thumb|250px|This solid gallium is fresh and after some time (2 months) at room temperature. Credit: Hi-Res Images of Chemical Elements.{{tlx|free media}}]]
[[Image:Gallium spectrum visible.png|center|thumb|400px|Gallium emission spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
While native gallium would be the best source of gallium, it apparently does not occur on Earth.
The image on the right is a drop of liquid gallium.

Gallium "enrichments are observed in the deep waters of the Norwegian Sea and Iceland Basin."<ref name=Shiller/>

"If northern deep water formation occurs at lower latitudes during glacial periods, the amount of sediment resuspension in the formation areas is likely to be affected with concomitant effects on the trace element content of newly formed northern-source deep waters."<ref name=Shiller>{{ cite journal
|author=Alan M. Shiller
|title=Dissolved gallium in the Atlantic Ocean
|journal=Marine Chemistry
|month=June
|year=1998
|volume=61
|issue=1-2
|pages=87-99
|url=http://www.sciencedirect.com/science/article/pii/S0304420398000097
|arxiv=
|bibcode=
|doi=10.1016/S0304-4203(98)00009-7
|pmid=
|accessdate=2014-10-29 }}</ref>

"At higher growth temperatures(>600'C) the lifetimes of the alkyl-gallium species are much shorter and the growth front dynamics should begin to look more like MBE since atomic gallium will be the dominant group III surface species."<ref name=Robertson>{{ cite journal
|author=A. Robertson Jr
|author2=T.H. Chiu
|author3=W.T. Tsang
|author4=J.E. Cunningham
|title=RHEED Intensity Oscillation Studies of the Kinetics of GaAs Deposition During Chemical Beam Epitaxy (CBE)
|journal=MRS Proceedings
|year=1987
|volume=102
|issue=
|pages=17-23
|url=http://journals.cambridge.org/abstract_S1946427400538469
|arxiv=
|bibcode=
|doi=http://dx.doi.org/10.1557/PROC-102-17
|pmid=
|accessdate=2012-07-17 }}</ref>

Gallite (CuGaS<sub>2</sub>) is 25 at % gallium.
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==Germaniums==
[[Image:Germanite from Tsumeb, Namibia.jpg|thumb|right|200px|This sample of germanite is displayed in the Smithsonian Museum of Natural History. Credit: R Nave.{{tlx|fairuse}}]]
[[Image:Polycrystalline-germanium.jpg|left|thumb|250px|This chunk is 12 grams of polycrystalline germanium, 2 x 3 cm. Credit: [[c:user:Jurii|Jurii]].{{tlx|free media}}]]
[[Image:Germanium spectrum visible.png|center|thumb|400px|Germanium emission spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The sample of germanite on the right has a composition of Cu<sub>26</sub>Fe<sub>4</sub>Ge<sub>4</sub>S<sub>32</sub>. Generally, germanite has a composition closer to Cu<sub>3</sub>(Ge, Ga, Fe, Zn) (S,As)<sub>4</sub>.<ref name=Roberts>{{ cite book
|author=Willard Lincoln Roberts
|author2=George Robert Rapp Jr.
|author3=Julius Weber
|title=Encyclopedia of Minerals
|publisher=Van Nostrand Reinhold Company
|location=New York, New York, USA
|date=1974
|editor=
|pages=121-2
|url=
|arxiv=
|bibcode=
|doi=
|pmid=
|{{isbn|0-442-26820-3}} }}</ref> "This sample also contains tennantite."<ref name=Nave>{{ cite web
|author=R Nave
|title=Germanite
|publisher=Smithsonian Museum of Natural History
|location=Washington, DS USA
|date=17 August 2015
|url=http://hyperphysics.phy-astr.gsu.edu/hbase/minerals/germanite.html
|accessdate=2015-08-17 }}</ref>
{{clear}}

==Golds==
[[Image:Gold-cat12a.jpg|thumb|right|250px|This very elaborate, 3-dimensional cluster of gold shows complex and minute crystallization patterns, and is overall hackly in texture. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
[[Image:Gold nugget (placer gold) 2 (17025829922).jpg|thumb|left|250px|This gold nugget (placer gold) is 9.5 mm across at its widest. Credit: [https://www.flickr.com/people/47445767@N05 James St. John].{{tlx|free media}}]]
[[Image:Gold spectrum visible.png|thumb|center|400px|Gold spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Gold (Au) is the most prestigious metal known, but it's not the most valuable. Gold is the only metal that has a deep, rich, metallic yellow color. Almost all other metals are silvery-colored. Gold is very rare in crustal rocks - it averages about 5 ppb (parts per billion). Where gold has been concentrated, it occurs as wires, dendritic crystals, twisted sheets, octahedral crystals, and variably-shaped nuggets. It most commonly occurs in hydrothermal quartz veins, disseminated in some contact- & hydrothermal-metamorphic rocks, and in placer deposits. Placers are concentrations of heavy minerals in stream gravels or in cracks on bedrock-floored streams. Gold has a high specific gravity (about 19), so it easily accumulates in placer deposits. Its high density allows prospectors to readily collect placer gold by panning.
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==Hafniums==
[[Image:Fe-Hf phase diagram.gif|thumb|right|250px|This is an iron-hafnium phase diagram. Credit: H. Okamoto.{{tlx|fairuse}}]]
[[Image:Hf-crystal bar.jpg|thumb|left|250px|A sample of a 1,7kg Hafnium crystal bar, made by van Arkel-de Boer process. Credit: [[c:user:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Hafnium spectrum visible.png|thumb|center|400px|Hafnium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Note in the iron-hafnium phase diagram on the left that hafnium occurs in two phases: hcp (α-Hf) at lower temperatures and bcc (β-Hf) at higher temperatures up to melting.

Hafnium is used in alloys with iron, titanium, niobium, tantalum, and other metals, for example the main engine of the Apollo Lunar Modules, is C103 which consists of 89% niobium, 10% hafnium and 1% titanium.<ref name=Hebda>{{cite web|title = Niobium alloys and high Temperature Applications|first = John|last = Hebda|publisher = CBMM|date = 2001|accessdate = 2008-09-04|url = https://web.archive.org/web/20081217080513/http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_3/images/pdfs/016.pdf|archive-date = 2008-12-17}}</ref>

Small additions of hafnium increase the adherence of protective oxide scales on nickel-based alloys, improving thereby the corrosion resistance especially under cyclic temperature conditions that tend to break oxide scales by inducing thermal stresses between the bulk material and the oxide layer.<ref name=Maslenkov>{{cite journal|title = Effect of hafnium on the structure and properties of nickel alloys|first = S. B.|last = Maslenkov |author2 = Burova, N. N. |author3=Khangulov, V. V. |journal = Metal Science and Heat Treatment|volume = 22|date = 1980|doi=10.1007/BF00779883|pages=283–285|issue = 4|bibcode = 1980MSHT...22..283M|s2cid = 135595958}}</ref><ref name=Beglov>{{cite journal|first = V. M.|last = Beglov |author2 = Pisarev, B. K. |author3=Reznikova, G. G. |title = Effect of boron and hafnium on the corrosion resistance of high-temperature nickel alloys|journal = Metal Science and Heat Treatment|volume = 34|date = 1992|doi = 10.1007/BF00702544|pages=251–254|issue = 4|bibcode = 1992MSHT...34..251B |s2cid = 135844921 }}</ref><ref name=Voitovich>{{cite journal|first = R. F.|last = Voitovich|author2=Golovko, É. I.|title = Oxidation of hafnium alloys with nickel|journal = Metal Science and Heat Treatment|volume = 17|date = 1975|doi = 10.1007/BF00663680|pages=207–209|issue = 3|bibcode = 1975MSHT...17..207V|s2cid = 137073174}}</ref>
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==Hassiums==

Hassium behaves as the heavier homologue to osmium, reacting readily with oxygen to form a volatile tetroxide.

==Heliums==
{{main|Chemicals/Heliums}}

==Holmiums==
[[Image:Holmium2.jpg|thumb|right|250px|Ultrapure holmium metal of 17 grams is shown. Credit: Unknown author.{{tlx|free media}}]]
[[Image:Holmium spectrum visible.png|thumb|center|400px|Holmium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Holmium spectrum.png|thumb|center|400px| Spectrum of holmium from a 12V spark, taken through a diffraction grating with a cellphone camera. Credit: [[c:user:Umop503|Umop503]].{{tlx|free media}}]]
"The constant of the alloy-formation rate for {{chem|HoNi|2}}, which was obtained in [22] at 1023 K in the LiCl–KCl eutectic melt, is 0.36 kg/m<sup>2</sup> h<sup>0.5</sup>."<ref name=Bushuev>{{ cite journal
|author=A. N. Bushuev, O. V. El’kin, I. V. Tolstobrova, A. V. Sazanov, and D. A. Kondrat’ev
|title=Preparation of a Nickel–Holmium Alloy Coating in an Equimolar {{chem|HoCl|3}}-Containing NaCl���KCl Melt
|journal=Russian Metallurgy (Metally)
|date=2018
|volume=2018
|issue=8
|pages=771-778
|url=https://www.researchgate.net/profile/Andrey-Bushuev-2/publication/329899928_Preparation_of_a_Nickel-Holmium_Alloy_Coating_in_an_Equimolar_HoCl3-Containing_NaCl-KCl_Melt/links/5dd4e7bf299bf11ec8629a72/Preparation-of-a-Nickel-Holmium-Alloy-Coating-in-an-Equimolar-HoCl3-Containing-NaCl-KCl-Melt.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=18 June 2022 }}</ref>
{{clear}}

==Hydrogens==
{{main|Chemicals/Hydrogens}}

==Indiums==
[[Image:Indium R060771 Eastern Transbaikal, Russia.jpg|thumb|right|200px|These pieces of native indium are from Eastern Transbaikal, Russia. Credit: Michael Scott.{{tlx|fairuse}}]]
[[Image:Indium spectrum visible.png|thumb|center|400px|Indium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Indium is an ingredient in the gallium–indium–tin alloy galinstan, which is liquid at room temperature and replaces mercury in some thermometers.<ref name=Surmann>{{cite journal|doi=10.1007/s00216-005-0069-7|date=Nov 2005|author=Surmann, P|author2=Zeyat, H| title=Voltammetric analysis using a self-renewable non-mercury electrode| volume=383|issue=6|pages=1009–13| pmid=16228199|journal= Analytical and Bioanalytical Chemistry|s2cid=22732411}}</ref> Other alloys of indium with bismuth, cadmium, lead, and tin, which have higher but still low melting points (between 50 and 100&nbsp;°C), are used in fire sprinkler systems and heat regulators.<ref name=Greenwood/>

"Indium minerals are very rare ; only 7 species have been defined so far : roquesite, CuInS<sub>2</sub> (Picot & Pierrot, 1963) ; indite, FeIn<sub>2</sub>S<sub>4</sub>, and dzhalindite, In(OH)<sub>3</sub> (Genkin & Murav'eva, 1963) ; sakuraiite, (Cu,Fe,Zn)<sub>3</sub>(In,Sn)S<sub>4</sub> (Kato, 1965) ; native indium (Ivanov, 1966b) ; yixunite, PtIn (Yu Tsu-Hsiang et al., 1976) ; petrukite, (Cu,Fe,Zn,Ag)<sub>3</sub>(Sn,In)S<sub>4</sub> (Kissin & Owens, 1989)."<ref name=Botelho>{{ cite journal
|author=Nilson F. Botelho
|author2=Guy Roger
|author3=Ferdinand d'Yvoire
|author4=Yves Moẽlo
|author5=Marcel Volfinger
|title=Yanomamite, InAsO<sub>4</sub>.2H<sub>2</sub>O, a new indium mineral from topaz-bearing greisen in the Gohiás Tin Province, Brazil
|journal=European Journal of Mineralogy
|date= 1994
|volume=6
|issue=
|pages=245-54
|url=https://rruff-2.geo.arizona.edu/uploads/EJM6_245.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=2015-02-22 }}</ref>

On the right are microprobe fragments of native indium from Eastern Transbaikal, Russia. The electron microprobe confirms that indium is the only component of the metallic phase.
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==Iodines==
{{main|Chemicals/Iodines}}

==Iridiums==
[[Image:Cubic native iridium crystal.png|thumb|right|250px|The image is of a cubic crystal of native iridium. Credit: Norman King.{{tlx|fairuse}}]]
[[Image:Iridium-2.jpg|thumb|left|250px|Pieces are pure iridium, 1 gram. Credit: Unknown author.{{tlx|free media}}]]
[[Image:Iridium spectrum visible.png|thumb|center|400px|Iridium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Native iridium such as the small cubic crystal shown in the image on the right is rare.

An alloy of iridium with ruthenium in thermocouples allowed for the measurement of high temperatures in air up to {{convert|2000|C}}.<ref name=Hunt>{{cite journal| title= A History of Iridium| first = L. B.| last =Hunt| journal = Platinum Metals Review| volume =31| issue = 1| date = 1987| url = http://www.platinummetalsreview.com/pdf/pmr-v31-i1-032-041.pdf| pages= 32–41}}</ref>

Iridium is found in nature as an uncombined element or in natural alloys; especially the iridium–osmium alloys, osmiridium (osmium-rich), and iridosmium (iridium-rich).<ref name=Emsley2003>{{cite book| title = Nature's Building Blocks: An A–Z Guide to the Elements| last = Emsley| first = J.| publisher = Oxford University Press| date = 2003| location = Oxford, England, UK| {{isbn|978-0-19-850340-8}}| chapter = Iridium| pages = 201–204]|url = https://archive.org/details/naturesbuildingb0000emsl/page/201}}</ref>
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==Irons==
[[Image:Native iron.jpg|thumb|right|250px|This piece from the Khungtukun Massif, Malaya Romanikha River, Khatanga, Taimyr Peninsula, Taymyrskiy Autonomous Okrug, Eastern-Siberian Region, Russia, displays inclusions of native iron. Credit: Hudson Institute of Mineralogy.{{tlx|fairuse}}]]
[[Image:Pure iron phase diagram (EN).png|thumb|left|250px|This diagram shows most of the phases of pure iron. Credit: [[c:User:Daniele Pugliesi|Daniele Pugliesi]] and [[c:User:Materialscientist|Materialscientist]].{{tlx|free media}}]]
[[Image:Iron III Flame Thermite Reaction.jpg|thumb|center|100px|The image shows the color of iron (III) orange in a thermite reaction. Credit: [[c:user:Denver & Rio Grande|Denver & Rio Grande]].
{{tlx|free media}}]].
[[Image:Epsilon iron unary phase diagram.jpg|thumb|left|250px|The unary (temperature-pressure) iron phase diagram shows the epsilon phase of iron at extremely high pressure. Credit: [[w:User:His Manliness|His Manliness]].{{tlx|free media}}]]
[[Image:Iron-252608.jpg|thumb|right|250px|An uncommon slabbed and polished specimen of lustrous, metallic, elemental native iron in basalt from Germany. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
[[Image:Cylinder of pure iron, 16 grams, 1 cm diameter..jpg|right|thumb|250px|Iron is a silvery, relatively reactive metal, which is very abundant and is used for multiple purposes. Credit: Hi-Res Images of Chemical Elements.{{tlx|free media}}]]
[[Image:Iron spectrum visible.png|thumb|center|400px|Iron spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The polished piece on the top right displays inclusions of native iron.

Iron occurs in several allotropes from α-Fe which has a body-centered cubic structure (bcc) at room temperature up to 910°C, γ-Fe which has a face-centered cubic (fcc) structure from 910°C to 1394°C, and δ-Fe (bcc) from 1394°C to 1538°C. Hexagonal close-packed (hcp) iron occurs at high pressures and temperatures as ε-Fe.

Austenite, also known as gamma-phase iron (γ-Fe), is a metallic, non-magnetic allotrope of iron or a solid solution of iron, with an alloying element.<ref name=ReedHill>{{cite book |authors=Reed-Hill R, Abbaschian R |title=Physical Metallurgy Principles |edition=3rd |publisher=PWS-Kent Publishing |location=Boston |year=1991 |{{isbn|978-0-534-92173-6}} }}</ref> In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1000 K (727&nbsp;°C); other alloys of steel have different eutectoid temperatures. The austenite allotrope is named after Sir William Chandler Roberts-Austen (1843–1902);<ref name=Gove>{{cite book |editor=Gove PB |title=Webster's Seventh New Collegiate Dictionary |publisher=G & C Merriam Company |location=Springfield, Massachusetts, USA |year=1963 |page=58 }}</ref> it exists at room temperature in some stainless steels due to the presence of nickel stabilizing the austenite at lower temperatures.
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==Meteoritic irons==
{{main|Radiation astronomy/Meteoritic irons}}

==Iron hydrides==

"Carroll and McCormack (1972) in Dublin reported complex spectra in the blue and green wavelength regions of both FeH and FeD".<ref name=JGPhillips>{{ cite journal
|author=John G. Phillips
|author2=Sumner P. Davis
|author3=Bo Lindgren
|author4=Walter J. Balfour
|title=The near-infrared spectrum of the FeH molecule
|journal=The Astrophysical Journal Supplement Series
|month=December
|year=1987
|volume=65
|issue=12
|pages=721-78
|url=
|arxiv=
|bibcode=1987ApJS...65..721P
|doi=10.1086/191241
|pmid=
|accessdate=2011-12-08 }}</ref>

"Carroll et al. (1976) detected a number of coincidences between laboratory lines of FeH and weak unidentified solar lines, again in the blue and green wavelength region, in addition to the infrared."<ref name=Fawzy>{{ cite journal
|author=DE Fawzy
|author2=NH Youssef
|author3=O. Engvold
|title=Identification of FeH molecular lines in the spectrum of a sunspot umbra
|journal=Astronomy and Astrophysics Supplement
|month=May
|year=1998
|volume=129
|issue=5
|pages=435-43
|url=http://aas.aanda.org/articles/aas/abs/1998/09/h0667/h0667.html
|arxiv=
|bibcode=1998A&AS..129..435F
|doi=10.1051/aas:1998196
|pmid=
|accessdate=2012-02-18 }}</ref>
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==Kryptons==
{{main|Chemicals/Kryptons}}

==Lanthanums==
[[Image:Lanthanum-2.jpg|thumb|right|250px|1 cm big piece is pure lanthanum. Credit: [[c:user:Jurii|Jurii]].{{tlx|free media}}]]
[[Image:Lanthanum spectrum visible.png|thumb|center|400px|Lanthanum spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Hydrogen sponge alloys can contain lanthanum and are capable of storing up to 400 times their own volume of hydrogen gas in a reversible adsorption process, where heat energy is released every time they do so; therefore these alloys have possibilities in energy conservation systems.<ref name=Lide2005>Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. {{ISBN|0-8493-0486-5}}.</ref><ref name=Uchida>{{cite journal | doi = 10.1016/S0360-3199(98)00161-X | title = Hydrogen solubility in rare earth based hydrogen storage alloys | date = 1999 | last1 = Uchida | first1 = H. | journal = International Journal of Hydrogen Energy | volume = 24 | pages = 871–877 | issue = 9}}</ref>

Mischmetal, a pyrophoric alloy used in lighter flints, contains 25% to 45% lanthanum.<ref name=Hammond/>
{{clear}}

==Lawrenciums==

The first ionization energy of lawrencium was measured, using the isotope <sup>256</sup>Lr.<ref name="Sato">{{cite journal |last1=Sato |first1=T. K. |last2=Asai |first2=M. |first3=A. |last3=Borschevsky |first4=T. |last4=Stora |first5=N. |last5=Sato |first6=Y. |last6=Kaneya |first7=K. |last7=Tsukada |first8=Ch. E. |last8=Düllman	 |first9=K. |last9=Eberhardt |first10=E. |last10=Eliav |first11=S. |last11=Ichikawa |first12=U. |last12=Kaldor |first13=J. V. |last13=Kratz |first14=S. |last14=Miyashita |first15=Y. |last15=Nagame |first16=K. |last16=Ooe |first17=A. |last17=Osa |first18=D. |last18=Renisch |first19=J. |last19=Runke |first20=M. |last20=Schädel |first21=P. |last21=Thörle-Pospiech |first22=A. |last22=Toyoshima |first23=N. |last23=Trautmann |date=9 April 2015 |title=Measurement of the first ionization potential of lawrencium, element 103 |journal=Nature |volume=520 |issue=7546 |pages=209–11 |doi=10.1038/nature14342 |bibcode = 2015Natur.520..209S |pmid=25855457|s2cid=4384213 |url=http://cds.cern.ch/record/2008656/files/TKSato-Lr-IP_prep_nature.pdf }}</ref> The measured value, {{nowrap|4.96{{su|p=+0.08|b=−0.07}} electronvolt (eV)}}, agreed very well with the relativistic theoretical prediction of 4.963(15)&nbsp;eV, and also provided a first step into measuring the first ionization energies of the transactinides.<ref name="Sato" /> This value is the lowest among all the lanthanides and actinides, and supports the s<sup>2</sup>p configuration as the 7p<sub>1/2</sub> electron is expected to be only weakly bound. This suggests that lutetium and lawrencium behave similarly to the d-block elements (and hence being the true heavier congeners of scandium and yttrium, instead of lanthanum and actinium). Although some alkali metal-like behaviour has been predicted,<ref name=Gunther>{{cite web |url=http://www.rsc.org/chemistryworld/2015/04/lawrencium-experiment-could-shake-periodic-table |title=Lawrencium experiment could shake up periodic table |last1=Gunther |first1=Matthew |date=9 April 2015 |website=RSC Chemistry World |access-date=21 September 2015}}</ref> adsorption experiments suggest that lawrencium is trivalent like scandium and yttrium, not monovalent like the alkali metals.<ref name=Haire2007>{{cite journal |last=Haire |first=R. G. |date=11 October 2007 |title=Insights into the bonding and electronic nature of heavy element materials |journal=Journal of Alloys and Compounds |volume=444–5 |pages=63–71 |doi=10.1016/j.jallcom.2007.01.103|url=https://zenodo.org/record/1259091 }}</ref>

==Leads==
[[Image:Lead-176678.jpg|right|thumb|150px|This is a piece of native lead. Credit: [[c:user:Rob Lavinsky|Rob Lavinsky]].{{tlx|free media}}]]
[[Image:A piece of lead.jpg|left|thumb|250px|A piece of lead, cut through, is silvery for a short time, before the surface oxidizes. Credit: Hi-Res Images of Chemical Elements.{{tlx|free media}}]]
[[Image:FlammenfärbungPb.png|thumb|center|100px|The image shows the color of lead in a natural gas burner. Credit: [[:de:user:Herge|Herge]].{{tlx|free media}}]].
[[Image:Lead spectrum visible.png|center|thumb|400px|Lead spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
"Diamond cubic structures with lattice parameters around the lattice parameter of silicon exists both in thin lead and tin films, and in massive lead and tin, freshly solidified in vacuum of ≈5 x 10<sup>-6</sup> Torr. Experimental evidence for almost identical structures of at least three oxide types is presented, demonstrating that lead and tin behave like silicon not only in the initial stages of crystallization, but also in the initial stages of oxidation."<ref name=Peneva>{{ cite journal
|author=S.K. Peneva, K.D. Djuneva and E.A. Tsukeva
|title=RHEED study of the initial stages of crystallization and oxidation of lead and tin
|journal=Journal of Crystal Growth
|month=2 May
|year=1981
|volume=53
|issue=2
|pages=382-396
|url=http://www.sciencedirect.com/science/article/pii/0022024881900889
|arxiv=
|bibcode=
|doi=10.1016/0022-0248(81)90088-9
|pmid=
|accessdate=2017-12-13 }}</ref>

The piece of native lead on the right shows a relatively sharp, and well-formed cuboctahedron of Lead at the top of the specimen, which is associated with elongated crystals on the base and back.

Its source locality is Långban, Filipstad, Värmland, Sweden.

A fresh surface of high purity lead on the left is silvery in appearance.

Lead tin telluride, PbSnTe or Pb<sub>1−x</sub>Sn<sub>x</sub>Te, is a ternary alloy of lead, tin and tellurium, generally made by alloying either tin into lead telluride or lead into tin Telluride.

In genuine Ashtadhatu, all eight metals (Au, Ag, Cu, Pb, Zn, Sn, Fe and Sb or Hg) are in equal proportion (12.5% each).<ref>[http://www.thedailystar.net/news-detail-260323 "The Eight Metals"]</ref><ref>[https://books.google.com/books?id=tG0fnF0VRk0C&pg=PA163&dq=Ashtadhatu&hl=en&sa=X&ved=0ahUKEwiLlZn_spXQAhVDxVQKHeLuAh4Q6AEIITAB#v=onepage&q=Ashtadhatu&f=false Social, Cultural, and Economic History of Himachal Pradesh]. Manjit Singh Ahluwalia. Indus Publishing. 1998 p. 163.</ref><ref>स्वर्ण रूप्यं ताम्रं च रंग यशदमेव च। शीसं लौहं रसश्चेति धातवोऽष्टौ प्रकीर्तिता:। Here rasa can be taken as either mercury or brass.</ref>

Sn, Pb, Cu, As, Sb are used to make Babbitt alloys.<ref name=Babbitt>Isaac Babbitt, http://pdfpiw.uspto.gov/.piw?Docid=00001252&idkey=NONE&homeurl=http%3A%252F%252Fpatft.uspto.gov%252Fnetahtml%252FPTO%252Fpatimg.htm "Mode of making boxes for axles and gudgeons," U.S. patent no. 1,252 (issued:  July 17, 1839).</ref> "The inner parts of the boxes are to be lined with any of the harder kinds of composition known under the names of britannia metal or pewter, of which block tin is the basis.  An excellent compound for this purpose I have prepared by taking about 50 parts of tin, five of antimony, and one of copper, but I do not intend to confine myself to this particular composition."<ref name=Babbitt/>
{{clear}}

==Lithiums==
{{main|Chemicals/Lithiums}}
[[Image:FlammenfärbungLi.png|thumb|left|100px|The image shows the color of lithium in a natural gas burner. Credit: [[:de:user:Herge|Herge]].{{tlx|free media}}]].
[[Image:Spectrum Lines of Li.png|thumb|center|400px|This spectrograph shows the visual spectral lines of lithium. Credit: [[w:User:T c951|T c951]].{{tlx|free media}}]]
[[Image:Lithium paraffin.jpg|right|thumb|300px|Lithium remains chemically inert when immersed in oil. Credit: [[:de:user:Tomihahndorf|Tomihahndorf]].{{tlx|free media}}]]
"[T]he standard solar models have enjoyed tremendous success recently in terms of agreement between the predicted outer structure and the results from helioseismology[, but] some observed properties of the [[Sun (star)|Sun]] still defy explanation, such as the degree of Li depletion" [the "solar Li abundance is roughly a factor of 200 below the meteoritic abundance"].<ref name=King>{{ cite journal
|author=Jeremy R. King
|author2=Constantine P. Deliyannis
|author3=Merchant Boesgaard
|title=The <sup>9</sup>Be Abundances of α Centauri A and B and the Sun: Implications for Stellar Evolution and Mixing
|journal=The Astrophysical Journal
|month=April 1,
|year=1997
|volume=478
|issue=2
|pages=778
|url=http://iopscience.iop.org/0004-637X/478/2/778/pdf/0004-637X_478_2_778.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=2012-07-11 }}</ref>
{{clear}}

==Livermoriums==

Although generated by heavy ion bombardment, the short-lived radioisotopes are not known to occur naturally on the surface of the Earth.

==Lutetiums==
[[Image:Lutetium sublimed dendritic and 1cm3 cube.jpg|thumb|right|250px|Lutetium, sublimed-dendritic, high purity 99.995 % Lu/TREM, as well as an argon arc remelted 1 cm3 lutetium (99,9 %) cube for comparison. Credit: [[c:user:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Lutetium spectrum visible.png|thumb|left|400px|Lutetium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Scandium, yttrium, and lutetium tend to occur together with the other lanthanides (except short-lived promethium) in the Earth's crust, and are often harder to extract from their ores.
{{clear}}

==Magnesiums==
[[Image:Magnesium Spectra.jpg|thumb|center|400px|This image shows the optical emission lines of magnesium. Credit: [[w:User:teravolt|teravolt]].{{tlx|free media}}]]
[[Image:CSIRO ScienceImage 2893 Crystalised magnesium.jpg|right|thumb|300px|Crystalized magnesium is shown. Credit: Mark Fergus, CSIRO.{{tlx|free media}}]]
[[Image:Magnesium-rich end with iron.png|thumb|left|250px|This portion of the iron-magnesium phase diagram is concentrated on the magnesium-rich end. Credit: A.A. Nayeb-Hashemi, J.B. Clark and L.J. Swartzendruber.{{tlx|fairuse}}]]
[[Image:Mg-flame.jpg|thumb|center|100px|The image shows the color of magnesium in a natural gas burner. Credit: KB.
{{tlx|fairuse}}]]
Magnesium has a hcp structure from room temperature up to melting. No other phases occur as is shown in the magnesium-end of the iron-magnesium phase diagram on the left.

Native magnesium is unlikely to occur on the surface of the Earth and is not known to occur.

Magnesium (Mg I) has an absorption band at 416.727±2.9 nm with an excitation potential of 4.33 eV.<ref name=Sadakane/>

Magnesium (Mg II) has an absorption band at 439.059±6.6 nm with an excitation potential of 9.96 eV.<ref name=Sadakane>{{ cite journal
|author=Kozo Sadakane
|author2=Minoru Ueta
|title=Abundance Analysis of Sirius in the Blue-Violet Region
|journal=Publications of the Astronomical Society of Japan
|month=August
|year=1989
|volume=41
|issue=2
|pages=279-88
|url=
|arxiv=
|bibcode=1989PASJ...41..279S
|doi=
|pmid=
|accessdate=2012-02-18 }}</ref>
{{clear}}

==Manganeses==
[[Image:Fe-Mn Phase Diagram.gif|thumb|left|250px|The pure manganese end member of this Fe-Mn phase diagram shows the higher temperature Mn phases. Credit: A. Rabinkin.]]
[[Image:Manganese element.jpg|right|thumb|250px|Two pieces of manganese metal are shown. Credit: W. Oelen.{{tlx|free media}}]]
[[Image:ManganeseFlameTestOxyHydrogen.png|thumb|center|200px|The image shows the color of manganese (II) in an oxy-hydrogen torch. Credit: [[c:user:NSEasternShoreChemist|NSEasternShoreChemist]].{{tlx|free media}}]].
[[Image:Manganese spectrum visible.png|center|thumb|400px|Manganese emission spectrum is from 400 nm - 700 nm Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
If native manganese occurs on Earth or nearby [[Solar System]] bodies, it likely occurs as bcc α-Mn.

"Beta manganese has a cubic crystal structure with space group P4132 [1]. The unit cell contains 20 atoms, divided between two non-equivalent sites."<ref name=Dunlop>{{ cite journal
|author=J.B. Dunlop
|author2=J.M. Williams
|author3=J. Crangle
|title=<sup>119</sup>Sn Mössbauer and neutron diffraction investigation of β Mn-Sn solid solutions
|journal=Physica B+C
|date=January-March 1977
|volume=86-88
|issue=
|pages=269-71
|url=http://www.sciencedirect.com/science/article/pii/0378436377903102
|arxiv=
|bibcode=
|doi=10.1016/0378-4363(77)90310-2
|pmid=
|accessdate=2015-08-19 }}</ref>

"The structures of γ- and δ-manganese are found to be face-centred cubic and body-centred cubic respectively."<ref name=Basinski>{{ cite journal
|author=Z. S. Basinski
|author2=J. W. Christian
|title=A Pressurized High-Temperature Debye-Scherrer Camera, and Its Use to Determine the Structures and Coefficients of Expansion of γ- and δ-manganese
|journal=The Royal Society Proceedings A
|date=20 May 1954
|volume=223
|issue=1155
|pages=554
|url=http://rspa.royalsocietypublishing.org/content/223/1155/554.short
|arxiv=
|bibcode=
|doi=10.1098/rspa.1954.0136
|pmid=
|accessdate=2015-08-19 }}</ref>

Manganese (Mn I) has two absorption bands at 403.449±1.4 nm and 405.554±0.8 nm, where the second has an excitation potential of 2.13 eV.<ref name=Sadakane/>

Manganese (Mn II) has an absorption band at 420.638±0.8 nm with an excitation potential of 5.37 eV.<ref name=Sadakane/>
{{clear}}

==Meitneriums==

Meitnerium is the seventh member of the 6d series of transition metals, and should be much like the platinum group metals.<ref name=Griffith>{{cite journal|doi=10.1595/147106708X297486|title=The Periodic Table and the Platinum Group Metals|date=2008|last1=Griffith|first1=W. P.|journal=Platinum Metals Review|volume=52|issue=2|pages=114–119 }}</ref> Calculations on its ionization potentials and atomic radius and ionic radii are similar to that of its lighter homologue iridium, thus implying that meitnerium's basic properties will resemble those of the other group 9 elements, cobalt, rhodium, and iridium.<ref name=Haire2007/>

==Mendeleviums==

Seventeen isotopes of mendelevium are known, with mass numbers from 244 to 260; all are radioactive.<ref name=Silva2006>Silva, Robert J. (2006). "Fermium, Mendelevium, Nobelium, and Lawrencium" (PDF). In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements. Vol. 3 (3rd ed.). Dordrecht: Springer. pp. 1621–1651. doi:10.1007/1-4020-3598-5_13. {{ISBN|978-1-4020-3555-5
]]. Archived from the original (PDF) on 2010-07-17.</ref> Additionally, five nuclear isomers are known: <sup>245m</sup>Md, <sup>247m</sup>Md, <sup>249m</sup>Md, <sup>254m</sup>Md, and <sup>258m</sup>Md.<ref name=Audi>Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001</ref><ref name=Nucleonica>{{cite web |url=http://www.nucleonica.net/unc.aspx |title=Universal Nuclide Chart |author=Nucleonica |date=2007–2014 |website=Nucleonica |access-date=22 May 2011}}</ref> Of these, the longest-lived isotope is <sup>258</sup>Md with a half-life of 51.5&nbsp;days, and the longest-lived isomer is <sup>258m</sup>Md with a half-life of 58.0&nbsp;minutes.<ref name=Audi/><ref name=Nucleonica/> Nevertheless, the shorter-lived <sup>256</sup>Md (half-life 1.17&nbsp;hours) is more often used in chemical experimentation because it can be produced in larger quantities from alpha particle irradiation of einsteinium.<ref name=Silva2006/>

==Mercuries==
{{main|Chemicals/Mercuries}}

==Metalloids==
[[Image:Native arsenic.jpg|thumb|right|200px|This massive native arsenic with quartz and calcite is from Ste. Marie-aux-mines, Alsace, France. Credit: [[c:User:Aramgutang|Aram Dulyan]].{{tlx|free media}}]]
'''Metalloids''' are elements whose properties are intermediate between metals and solid nonmetals or semiconductors.

A variety of elements are often considered metalloids:
# boron, considered here in [[Radiation astronomy/Alloys#Borons|Borons]],
# aluminum, a face-centered cubic metal, considered in [[Radiation astronomy/Alloys#Aluminums|Aluminums]],
# silicon, here in [[Radiation astronomy/Alloys#Silicons|Silicons]],
# gallium, here in [[Radiation astronomy/Alloys#Galliums|Galliums]],
# germanium, here in [[Radiation astronomy/Alloys#Germaniums|Germaniums]],
# arsenic, here in [[Radiation astronomy/Alloys#Arsenics|Arsenics]],
# selenium, here in [[Radiation astronomy/Alloys#Seleniums|Seleniums]], also included in the [[Minerals/Chalcogens|chalcogens]],
# indium, here in [[Radiation astronomy/Alloys#Indiums|Indiums]],
# tin, here in [[Radiation astronomy/Alloys#Tins|Tins]],
# antimony, here in [[Radiation astronomy/Alloys#Antimonies|Antimonies]],
# tellurium, here in [[Radiation astronomy/Alloys#Telluriums|Telluriums]], also included in the [[Minerals/Chalcogens|chalcogens]],
# polonium, here in [[Radiation astronomy/Alloys#Poloniums|Poloniums]], and
# astatine, here in [[Radiation astronomy/Alloys#Astatines|Astatines]], with the [[Minerals/Halogens|halogens]].
{{clear}}

==Moscoviums==

The moscovium isotopes <sup>288</sup>Mc, <sup>289</sup>Mc, and <sup>290</sup>Mc may be chemically investigated with current methods, although their short half-lives would make this challenging.<ref name=Eichler>{{cite journal |last=Eichler |first=Robert |date=2013 |title=First foot prints of chemistry on the shore of the Island of Superheavy Elements |journal=Journal of Physics: Conference Series |publisher=IOP Science |volume=420 |issue=1 |pages=012003 |doi=10.1088/1742-6596/420/1/012003 |bibcode=2013JPhCS.420a2003E |arxiv=1212.4292 |s2cid=55653705 }}</ref> Moscovium is the heaviest element that has known isotopes that are long-lived enough for chemical experimentation.<ref name=Moody>{{cite book |chapter=Synthesis of Superheavy Elements |last1=Moody |first1=Ken |editor1-first=Matthias |editor1-last=Schädel |editor2-first=Dawn |editor2-last=Shaughnessy |title=The Chemistry of Superheavy Elements |publisher=Springer Science & Business Media |edition=2nd |pages=24–8 |isbn=9783642374661|date=2013-11-30 }}</ref>

==Molybdenums==
[[Image:Native molybdenum Luna 24 landing site.jpg|thumb|right|200px|This is a scanning electron micrograph of native molybdenum particles in lunar regolith. Credit: A. V. Mokhov and P. M. Kartashov.{{tlx|fairuse}}]]
[[Image:Molybdenum spectrum visible.png|thumb|center|400px|Molybdenum spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Fe-Mo Phase Diagram.gif|thumb|left|250px|This is a calculated iron-molybdenum phase diagram. Credit: Computational Thermodynamics Inc.{{tlx|fairuse}}]]
The electron micrograph on the right shows a couple of pieces of native molybdenum found in lunar regolith at the Luna 24 landing site after transport back to [[Earth]] and analysis.

The phase diagram for the iron-molybdenum system demonstrates that molybdenum is bcc (α-Mo) for its intermediate and higher temperatures. It's also bcc at room temperature.

Molybdenum can withstand extreme temperatures without significantly expanding or softening, making it useful in environments of intense heat.<ref name=Emsley2001>{{cite book|last = Emsley|first = John|title = Nature's Building Blocks|url=https://books.google.com/books?id=j-Xu07p3cKwC&pg=PA265|publisher = Oxford University Press|date= 2001|location = Oxford|pages = 262–266|{{isbn|978-0-19-850341-5}} }}</ref><ref name="azom">{{cite web|title=Molybdenum|publisher=AZoM.com Pty. Limited|date=2007|accessdate=2007-05-06|url=https://web.archive.org/web/20110614171110/http://www.azom.com/article.aspx?ArticleID=616|archive-date=2011-06-14 }}</ref>
{{clear}}

==Neodymiums==
[[Image:Neodymium2.jpg|thumb|right|250px|Ultrapure neodymium is shown under argon, 5 grams. C Credit: Unknown author.{{tlx|free media}}]]
[[Image:Neodymium spectrum visible.png|thumb|center|400px|Neodymium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Thorianite contains the oxides of uranium, lanthanum, cerium, praseodymium and neodymium.

"Along with uranium, zinc, iron ore, copper and gold, Greenland’s ancient rocks also harbor large quantities of those minerals known as “rare earth,” among them lanthanum, cerium, neodymium, praesodymium, terbium and yttrium."<ref name=Weiden>{{ cite book
|author=Silvia von der Weiden
|title=As Greenland's Glaciers Recede, A Rush On The Riches Buried Below
|publisher=WorldCrunch
|location=
|date=21 March 2012
|url=http://www.worldcrunch.com/business-finance/as-greenland-s-glaciers-recede-a-rush-on-the-riches-buried-below/c2s4915/
|accessdate=20 September 2014 }}</ref>

Neodymium is in the alloys used to make high-strength neodymium magnets—a type of powerful permanent magnet.<ref>[https://www.toshiba.co.jp/about/press/2012_08/pr1601.htm Toshiba Develops Dysprosium-free Samarium-Cobalt Magnet to Replace Heat-resistant Neodymium Magnet in Essential Applications]. Toshiba (2012-08-16). Retrieved on 2012-09-24.</ref>

To make neodymium magnets it is alloyed with iron, which is a ferromagnet.<ref name=Stamenov>Stamenov P. (2021) Magnetism of the Elements. In: Coey J.M.D., Parkin S.S. (eds) Handbook of Magnetism and Magnetic Materials. Springer, Cham. https://doi.org/10.1007/978-3-030-63210-6_15</ref>

Neodymium magnets, an alloy, Nd<sub>2</sub>Fe<sub>14</sub>B, are the strongest permanent magnets known<ref name=Zhang>Zhang, W., Liu, G. & Han, K. The Fe-Nd (Iron-Neodymium) system. JPE 13, 645–648 (1992). https://doi.org/10.1007/BF02667216</ref> and tend to corrode.<ref name=Bala>Bala, H., Szymura, S., Pawłowska, G. et al. Effect of impurities on the corrosion behaviour of neodymium. J Appl Electrochem 23, 1017–1024 (1993). https://doi.org/10.1007/BF00266123</ref>
{{clear}}

==Neons==
{{main|Chemicals/Neons}}

==Neptuniums==
[[Image:Neptunium Aeschynite.png|thumb|right|250px|This mineral, Aeschynite, probably contains on the order of a few atoms of neptunium at any one time, as part of the complex decay chain of the uranium that makes up a much larger fraction of the sample. Credit: Theodore Gray.{{tlx|fairuse}}]]
[[Image:Neptunium spectrum visible.png|thumb|center|400px|Neptunium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The image at the right shows a rock with the mineral Aeschynite approximately centered above the biotite mica. Aeschynite "probably contains on the order of a few atoms of neptunium at any one time, as part of the complex decay chain of the uranium that makes up a much larger fraction of the sample."<ref name=GrayNeptunium>{{ cite web
|author=Theodore Gray
|title=An example of the element Neptunium
|publisher=Periodic Table.com
|location=
|date=20 September 2005
|url=http://periodictable.com/Items/093.2/index.html
|accessdate=2015-11-05 }}</ref>

Pure neptunium is paramagnetic, NpAl<sub>3</sub> is ferromagnetic, NpGe<sub>3</sub> has no magnetic ordering, and NpSn<sub>3</sub> behaves fermionically.<ref name=Yoshida>{{cite book |last1=Yoshida |first1 = Zenko|first2 = Stephen G.|last2 = Johnson|first3 = Takaumi|last3 = Kimura|first4 = John R.|last4=Krsul|title = The Chemistry of the Actinide and Transactinide Elements|editor1-first = Lester R.|editor1-last = Morss|editor2-first = Norman M.|editor2-last = Edelstein|editor3-first = Jean|editor3-last = Fuger|edition = 3rd|date = 2006|volume = 3|publisher = Springer|location = Dordrecht, the Netherlands|pages = 699–812
|doi = 10.1007/1-4020-3598-5_6
|url=https://web.archive.org/web/20180117190715/http://radchem.nevada.edu/classes/rdch710/files/neptunium.pdf|archive-date=January 17, 2018|{{isbn|978-1-4020-3555-5}} }}</ref>
{{clear}}

==Nickels==
{{main|Chemicals/Nickels}}
[[Image:Nickel chunk.jpg|right|thumb|250px|This piece of Ni is about 3 cm in size. Credit: [[w:user:Materialscientist|Materialscientist]].{{tlx|free media}}]]
[[Image:Nickel spectrum visible.png|thumb|center|400px|This is an emission-line spectrum for nickel over the visible range: 400-700 nm. Credit: [[c:User:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:NickelFlameTestOxyHydrogen.png|thumb|center|200px|The image shows the color of nickel in an oxy-hydrogen flame. Credit: [[c:user:NSEasternShoreChemist|NSEasternShoreChemist]].
{{tlx|free media}}]].
Nickel has an emission line occurring in the solar corona at 511.603 nm from Ni XIII.<ref name=Swings>{{ cite journal
|author=P. Swings
|title=Edlén's Identification of the Coronal Lines with Forbidden Lines of Fe X, XI, XIII, XIV, XV; Ni XII, XIII, XV, XVI; Ca XII, XIII, XV; a X, XIV
|journal=The Astrophysical Journal
|month=July
|year=1943
|volume=98
|issue=07
|pages=116-28
|url=
|arxiv=
|bibcode=1943ApJ....98..116S
|doi=10.1086/144550
|pmid=
|accessdate=2013-01-18 }}</ref>

Nickel has an emission line occurring in the solar corona at 670.183 nm from Ni XV.<ref name=Swings/>

Nickel has three emission lines occurring in the solar corona at 380.08 nm of Ni XIII and 423.14 nm and 431.1 of Ni XII.<ref name=Swings/>

Nickel has an absorption band at 401.550-436.210 nm with an excitation potential of 4.01 eV.<ref name=Sadakane/>

Antitaenite is a meteoritic metal alloy mineral composed of iron and nickel, 20-40% Ni (and traces of other elements).<ref name=Rancourt1995>D.G. Rancourt and R.B. Scorzelli. Low Spin γ-Fe-Ni (γLS) Proposed as a New Mineral in Fe-Ni-Bearing Meteorites: Epitaxial Intergrowth of γLS and Tetrataenite as Possible Equilibrium State at ~20-40 at % Ni.  ''Journal of Magnetism and Magnetic Materials'' 150 (1995) 30-36</ref>

Breithauptite is a nickel antimonide mineral with the simple formula NiSb.

Niccolite has the chemical formula NiAs.<ref name=Roberts/>
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==Nihoniums==

Stability of a nucleus is provided by the strong interaction. However, its range is very short; as nuclei become larger, their influence on the outermost nucleons (protons and neutrons) weakens. At the same time, the nucleus is torn apart by electrostatic repulsion between protons, as it has unlimited range.<ref>Beiser, A. (2003). Concepts of modern physics (6th ed.). McGraw-Hill. {{ISBN|978-0-07-244848-1}}. OCLC 48965418.</ref> Nuclei of the heaviest elements are thus theoretically predicted<ref name=Staszczak>{{Cite journal|last=Staszczak|first=A.|last2=Baran|first2=A.|last3=Nazarewicz|first3=W.|date=2013|title=Spontaneous fission modes and lifetimes of superheavy elements in the nuclear density functional theory|journal=Physical Review C|volume=87|issue=2|pages=024320–1|doi=10.1103/physrevc.87.024320|arxiv=1208.1215|bibcode=2013PhRvC..87b4320S|issn=0556-2813}}</ref> and have so far been observed<ref>Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.</ref> to primarily decay via decay modes that are caused by such repulsion: alpha decay and spontaneous fission; not all decay modes are caused by electrostatic repulsion. For example, beta decay is caused by the weak interaction.<ref>Beiser, A. (2003). Concepts of modern physics (6th ed.). McGraw-Hill. {{ISBN|978-0-07-244848-1}}. OCLC 48965418.</ref> these modes are predominant for nuclei of superheavy elements. Alpha decays are registered by the emitted alpha particles, and the decay products are easy to determine before the actual decay; if such a decay or a series of consecutive decays produces a known nucleus, the original product of a reaction can be determined arithmetically. Since mass of a nucleus is not measured directly but is rather calculated from that of another nucleus, such measurement is called indirect. Direct measurements are also possible, but for the most part they have remained unavailable for heaviest nuclei.<ref>{{Cite journal|last=Oganessian|first=Yu. Ts.|last2=Rykaczewski|first2=K. P.|date=2015|title=A beachhead on the island of stability|journal=Physics Today|volume=68|issue=8|pages=32–38|doi=10.1063/PT.3.2880|bibcode=2015PhT....68h..32O|osti=1337838|issn=0031-9228|url=https://www.osti.gov/biblio/1337838}}</ref> The first direct measurement of mass of a superheavy nucleus was reported in 2018 at LBNL.<ref name=Grant>{{Cite journal|last=Grant |first=A.|date=2018|title=Weighing the heaviest elements|journal=Physics Today|doi=10.1063/PT.6.1.20181113a}}</ref> Mass was determined from the location of a nucleus after the transfer (the location helps determine its trajectory, which is linked to the mass-to-charge ratio of the nucleus, since the transfer was done in presence of a magnet).<ref name=Howes>{{Cite web|url=https://cen.acs.org/physical-chemistry/periodic-table/IYPT-Exploring-the-superheavy-elements-at-the-end-of-the-periodic-table/97/i21|title=Exploring the superheavy elements at the end of the periodic table|last=Howes|first=L.|date=2019|website=Chemical & Engineering News|accessdate=2020-01-27}}</ref> Spontaneous fission, however, produces various nuclei as products, so the original nuclide cannot be determined from its daughters.<ref name=Robinson>{{Cite journal|last=Robinson|first=A. E.|url=https://www.sciencehistory.org/distillations/the-transfermium-wars-scientific-brawling-and-name-calling-during-the-cold-war|title=The Transfermium Wars: Scientific Brawling and Name-Calling during the Cold War|date=2019|journal=Distillations|accessdate=2020-02-22}}</ref> a leading scientist at JINR, and thus it was a "hobbyhorse" for the facility.<ref name="coldfusion77">{{Cite web|url=http://n-t.ru/ri/ps/pb106.htm|title=Популярная библиотека химических элементов. Сиборгий (экавольфрам)|trans-title=Popular library of chemical elements. Seaborgium (eka-tungsten)|language=ru|website=n-t.ru|accessdate=2020-01-07}} Reprinted from {{cite book|author=<!--none-->|date=1977|title=Популярная библиотека химических элементов. Серебро — Нильсборий и далее|chapter=Экавольфрам|trans-title=Popular library of chemical elements. Silver through nielsbohrium and beyond|trans-chapter=Eka-tungsten|language=ru|publisher=Nauka }}</ref> In contrast, the LBL scientists believed fission information was not sufficient for a claim of synthesis of an element. They believed spontaneous fission had not been studied enough to use it for identification of a new element, since there was a difficulty of establishing that a compound nucleus had only ejected neutrons and not charged particles like protons or alpha particles.<ref name=Hyde>{{Cite journal|last=Hyde|first=E. K.|last2=Hoffman|first2=D. C.|author-link2=Darleane C. Hoffman|last3=Keller|first3=O. L.|date=1987|title=A History and Analysis of the Discovery of Elements 104 and 105|journal=Radiochimica Acta|volume=42|issue=2|doi=10.1524/ract.1987.42.2.57|issn=2193-3405|pages=67–68|url=http://www.escholarship.org/uc/item/05x8w9h7}}</ref> They thus preferred to link new isotopes to the already known ones by successive alpha decays.<ref name=Robinson/>

==Nihonium monofluorides==

The analogous monofluoride (NhF) should also exist.<ref name="Stysziński">{{cite book |chapter=Why do we Need Relativistic Computational Methods? |title=Relativistic Methods for Chemists |volume=10 |last=Stysziński |first=Jacek |doi=10.1007/978-1-4020-9975-5_3 |date=2010 |pages=139–146 |isbn=978-1-4020-9974-8|series=Challenges and Advances in Computational Chemistry and Physics}}</ref>

==Nihonium monohydrides==

The simplest possible nihonium compound is the monohydride, NhH. The bonding is provided by the 7p<sub>1/2</sub> electron of nihonium and the 1s electron of hydrogen. The SO interaction causes the binding energy of nihonium monohydride to be reduced by about 1&nbsp;eV<ref name=Hoffman>Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. {{ISBN|978-1-4020-3555-5}}.</ref> and the nihonium–hydrogen bond length to decrease as the bonding 7p<sub>1/2</sub> orbital is relativistically contracted. This is unique among the 7p element monohydrides; all the others have relativistic expansion of the bond length instead of contraction.<ref name="hydride">{{cite journal |journal=Journal of Chemical Physics |volume=112 |issue=6 |year=2000 |title=Spin–orbit effects on the transactinide p-block element monohydrides MH (M=element 113–118) |first1=Young-Kyu |last1=Han |first2=Cheolbeom |last2=Bae |first3=Sang-Kil |last3=Son |first4=Yoon Sup |last4=Lee |doi=10.1063/1.480842 |page=2684 |bibcode=2000JChPh.112.2684H|s2cid=9959620 |url=https://semanticscholar.org/paper/bb2beba2bc47c3381ed69b7125f6fbfb4b98596a}}</ref> Another effect of the SO interaction is that the Nh–H bond is expected to have significant pi bonding character (side-on orbital overlap), unlike the almost pure sigma bonding (head-on orbital overlap) in thallium monohydride (TlH).<ref name="Seth">{{cite journal |last1=Seth |first1=Michael |last2=Schwerdtfeger |first2=Peter |first3=Knut |last3=Fægri |date=1999 |title=The chemistry of superheavy elements. III. Theoretical studies on element 113 compounds |journal=Journal of Chemical Physics |volume=111 |issue=14 |pages=6422–6433 |doi=10.1063/1.480168 |bibcode=1999JChPh.111.6422S|s2cid=41854842 |url=https://semanticscholar.org/paper/9aaa02788fada5fa2fe16de76ad51718d31b68f8}}</ref>

==Nihonium monoiodides==

Nihonium(I) is predicted to be more similar to silver(I) than thallium(I):<ref name=Hoffman/> the Nh<sup>+</sup> ion is expected to more willingly bind anions, so that NhCl should be quite soluble in excess hydrochloric acid or ammonia; thallium(I) chloride (TlCl) is not. In contrast to Tl<sup>+</sup>, which forms the strongly basic hydroxide (thallium(I) hydroxide (TlOH)) in solution, the Nh<sup>+</sup> cation should instead hydrolyse all the way to the amphoteric oxide Nh<sub>2</sub>O, which would be soluble in aqueous ammonia and weakly soluble in water.<ref>Fricke, Burkhard (1975). "Superheavy elements: a prediction of their chemical and physical properties". Recent Impact of Physics on Inorganic Chemistry. Structure and Bonding. 21: 89–144. doi:10.1007/BFb0116498. {{ISBN|978-3-540-07109-9}}. Retrieved 4 October 2013.</ref>

==Niobiums==
[[Image:Iron-niobium phase diagram.png|thumb|left|200px|This is an iron-niobium phase diagram. Credit: E. Paul and L.J. Swartendruber.{{tlx|fairuse}}]]
[[Image:Niobium crystals and 1cm3 cube.jpg|thumb|right|250px|High purity (99.995 % = 4N5) niobium crystals, electrolytic made, as well as a high purity (99.95 % = 3N5) 1 cm3 anodized niobium cube for comparison. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Niobium spectrum visible.png|thumb|center|400px|Niobium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
As can be seen in the iron-niobium phase diagram on the left, niobium is single phase (α-Nb) up to its melting temperature. This is a bcc structure.

Ferroniobium is an alloy of 60–70% niobium with iron, where niobium is used mostly in alloy steel.<ref name=Tither>{{cite book|title = Progress in Niobium Markets and Technology 1981–2001|author = Tither, Geoffrey|journal = Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA)|date = 2001|{{isbn|978-0-9712068-0-9}}|editor = Minerals, Metals and Materials Society|url = https://web.archive.org/web/20081217100553/http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/images/pdfs/oppening.pdf| }}</ref><ref name=Dufresne>{{cite book|title=The Production of Ferroniobium at the Niobec mine 1981–2001 |first=Claude |last=Dufresne |author2=Goyette, Ghislain|journal=Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) |date=2001 |{{isbn|978-0-9712068-0-9}} |editor = Minerals, Metals and Materials Society|url=https://web.archive.org/web/20081217100559/http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_1/images/pdfs/start.pdf }}</ref><ref>{{cite web
|title = ASTM A572 / A572M-18, Standard Specification for High-Strength Low-Alloy Columbium-Vanadium Structural Steel
| publisher = ASTM International, West Conshohocken
| date = 2018
| accessdate = 2020-02-12
|url = https://web.archive.org/web/20200212215757/https://www.astm.org/Standards/A572 }}</ref> Niobium is used in various superconducting materials, Type-II superconductor alloys, also containing titanium and tin. Quantities of niobium are used in nickel-, cobalt-, and iron-based superalloys in proportions as great as 6.5%.<ref name=Heisterkamp>{{cite book|title = Niobium: Future Possibilities – Technology and the Market Place|first = Friedrich|last = Heisterkamp|author2 = Carneiro, Tadeu|journal = Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA)|date = 2001|{{isbn|978-0-9712068-0-9}}|editor = Minerals, Metals and Materials Society|url = https://web.archive.org/web/20081217100604/http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/images/pdfs/closing.pdf }}</ref>

It appears to be the case that native niobium does not occur in the surface rocks on Earth.
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==Nitrogens==
{{main|Chemicals/Nitrogens}}

==Carlsbergites==
[[Image:Agpalilik.jpg|right|thumb|300px|Agpalilik meteorite is outside the Geological Museum in Copenhagen. Credit: [[c:user:FunkMonk|Michael B. H.]].{{tlx|free media}}]]
Carlsbergite was first described in the Agpalilik fragment of the Cape York meteorite.

It is a chromium nitride mineral (CrN),<ref name=WebmineralCarlsbergites>{{cite web|title=Carlsbergite|url=http://webmineral.com/data/Carlsbergite.shtml|publisher=Webmineral|accessdate=10 January 2013}}</ref> named after the Carlsberg Foundation that backed the recovery of the Agpalilik fragment from the Cape York meteorite.<ref name=WebmineralCarlsbergites/>

It occurs in meteorites along the grain boundaries of kamacite or troilite in the form of tiny plates,<ref name=WebmineralCarlsbergites/> associated with kamacite, taenite, daubreelite, troilite and sphalerite.<ref name=HandbookCarlsbergites>[http://www.handbookofmineralogy.com/pdfs/carlsbergite.pdf Carlsbergite in the Handbook of Mineralogy]</ref>
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==Nobeliums==

A nobelium atom has 102 electrons, of which three can act as valence electrons. They are expected to be arranged in the configuration [Rn]5f<sup>14</sup>7s<sup>2</sup> (ground state term symbol <sup>1</sup>S<sub>0</sub>), although experimental verification of this electron configuration had not yet been made as of 2006.<ref name=Silva2011>Silva, Robert J. (2011). "Chapter 13. Fermium, Mendelevium, Nobelium, and Lawrencium". In Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements. Netherlands: Springer. pp. 1621–1651. doi:10.1007/978-94-007-0211-0_13. {{ISBN|978-94-007-0210-3}}.</ref> In forming compounds, all the three valence electrons may be lost, leaving behind a [Rn]5f<sup>13</sup> core: this conforms to the trend set by the other actinides with their [Rn]5f<sup>''n''</sup> electron configurations in the tripositive state. Nevertheless, it is more likely that only two valence electrons may be lost, leaving behind a stable [Rn]5f<sup>14</sup> core with a filled 5f<sup>14</sup> shell. The first ionization potential of nobelium was measured to be at most (6.65&nbsp;±&nbsp;0.07)&nbsp;eV in 1974, based on the assumption that the 7s electrons would ionize before the 5f ones;<ref name=Martin>{{cite journal |first1=William C. |last1=Martin |first2=Lucy |last2=Hagan |first3=Joseph |last3=Reader |first4=Jack |last4=Sugar |s2cid=97945150 |date=1974 |title=Ground Levels and Ionization Potentials for Lanthanide and Actinide Atoms and Ions |journal=Journal of Physical and Chemical Reference Data |volume=3 |issue=3 |pages=771–9 |doi=10.1063/1.3253147 |bibcode=1974JPCRD...3..771M |url=https://web.archive.org/web/20200215124722/https://pdfs.semanticscholar.org/9618/febdd51cee0e84ff7af88767be47cfcd4818.pdf }}</ref> this value has not yet been refined further due to nobelium's scarcity and high radioactivity.<ref name=Lide2003>Lide, David R. (editor), ''CRC Handbook of Chemistry and Physics, 84th Edition'', CRC Press, Boca Raton (FL), 2003, section 10, ''Atomic, Molecular, and Optical Physics; Ionization Potentials of Atoms and Atomic Ions''</ref> The ionic radius of hexacoordinate and octacoordinate No<sup>3+</sup> had been preliminarily estimated in 1978 to be around 90 and 102&nbsp;pm respectively;<ref name=Silva2011/> the ionic radius of No<sup>2+</sup> has been experimentally found to be 100&nbsp;pm to two significant figures.<ref name=Silva2011/> The enthalpy of hydration of No<sup>2+</sup> has been calculated as 1486&nbsp;kJ/mol.<ref name=Silva2011/>

==Oganessons==

Although oganesson is a member of group 18 (the noble gases) – the first synthetic element to be so – it may be significantly reactive, unlike all the other elements of that group.<ref name=Nash2005>Nash, Clinton S. (2005). "Atomic and Molecular Properties of Elements 112, 114, and 118". Journal of Physical Chemistry A. 109 (15): 3493–3500. Bibcode:2005JPCA..109.3493N. doi:10.1021/jp050736o. {{PMID|16833687}}.</ref> It was formerly thought to be a gas under standard conditions for temperature and pressure but is now predicted to be a solid due to relativistic effects.<ref name="Nash2005" />

==Osmiums==
[[Image:Native Osmium crystal.png|thumb|right|250px|A crystal of native osmium from Nishni Tagil, Ural, Russia, is shown. Credit: Thomas Witzke.{{tlx|fairuse}}]]
[[Image:Osmium crystals.jpg|thumb|left|250px|Osmium Os shown are crystals, purity ≥ 99.99%, 2.2 g. Credit: [[c:user:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Osmium spectrum visible.png|thumb|center|400px|Osmium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The crystal of native osmium shown on the right is about 2 mm across.

Osmium alloys with platinum, iridium, and other platinum-group metals.<ref name=Haynes>Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). CRC Press. {{ISBN|978-1439855119}}.</ref>
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==Oxygens==
{{main|Chemicals/Oxygens}}

==Palladiums==
[[Image:Palladium nugget Brazil.png|thumb|right|250px|This is a palladium nugget. Credit: Hudson Institute of Mineralogy.
{{tlx|fairuse}}]]
[[Image:Palladium Mednorudyanskoye Cu Deposit.jpg|thumb|left|250px|This piece of native palladium is from the Mednorudyanskoye Cu Deposit, Nizhnii Tagil, Sverdlovskaya Oblast', Middle Urals, Urals Region, Russia. Credit: Hudson Institute of Mineralogy.{{tlx|fairuse}}]]
[[Image:Palladium spectrum visible.png|thumb|center|400px|Palladium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
"Natural Palladium [like the nugget shown on the right] always contains some Platinum."<ref name=Hudson2015>{{ cite book
|author=Hudson Institute of Mineralogy
|title=Palladium
|publisher=Mindat
|location=
|date=29 October 2015
|url=http://www.mindat.org/min-3067.html
|accessdate=2015-11-04 }}</ref>

This palladium nugget is from Bom Sucesso Creek, Serro, Minas Gerais, Brazil.

"(Pd,Cu) alloys, some with the approximate composition PdCu<sub>4</sub>, are reported by Kapsiotis et al. (2010)."<ref name=Hudson2015/>

The piece of native palladium [image on the left] from the Mednorudyanskoye Cu Deposit, Nizhnii Tagil, Sverdlovskaya Oblast', Middle Urals, Urals Region, Russia, probably contains some copper.

Palladium can be found as a free metal alloyed with gold and other platinum-group metals in placer deposits of the Ural Mountains, Australia, Ethiopia, North and South America.

Palladium is found in the rare minerals cooperite<ref name=Verryn>{{cite journal|journal=Mineralogical Magazine|date=1994|volume=58|issue= 2|pages=223–234|title=Compositional variation of cooperite, braggite, and vysotskite from the Bushveld Complex|first1=Sabine M. C.| last1 =Verryn|first2=Roland K. W.|last2=Merkle|doi=10.1180/minmag.1994.058.391.05|bibcode=1994MinM...58..223V|citeseerx=10.1.1.610.640}}</ref> and polarite.<ref name=Genkin>{{cite journal|last1 = Genkin|first1 = A. D.|last2 = Evstigneeva|first2 = T. L.|date = 1986|title = Associations of platinum- group minerals of the Norilsk copper-nickel sulfide ores|journal = Economic Geology|volume = 81|pages = 1203–1212|doi = 10.2113/gsecongeo.81.5.1203|issue = 5}}</ref> Many more Pd minerals are known, but all of them are very rare.<ref>{{Cite web|url=https://www.mindat.org/|title=Mindat.org - Mines, Minerals and More|website=www.mindat.org}}</ref>
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==Potarites==
[[Image:Potarite from Brazil.jpg|thumb|right|250px|This piece of potarite is from Serro, Minas Gerais, Brazil. Credit: Hudson Institute of Mineralogy.{{tlx|fairuse}}]]
Potarite has the chemical formula PdHg.<ref name=Roberts/>

On the right is a piece of potarite is from Serro, Minas Gerais, Brazil.
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==Phosphoruses==
[[Image:PhosphorusAllotropes.svg|400px|thumb|center|White phosphorus and resulting allotropes, including violet phosphorus, are indicated. Credit: [[c:User:UserXresu|UserXresu]].{{tlx|free media}}]]
[[Image:PhosphComby.jpg|thumb|right|250px|White phosphorus is under water on the left, with red phosphorus (center images), and violet phosporus right. Credit: [[c:User:Materialscientist|Materialscientist]].{{tlx|free media}}]]
[[Image:Phosphorus spectrum visible.png|center|thumb|400px|Phosphorus spectrum is for emission lines between 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Phosphorus has several allotropes that exhibit strikingly diverse properties.<ref name=Holleman>{{Cite book|author=A. Holleman|author2=N. Wiberg|title=Lehrbuch der Anorganischen Chemie|publisher= de Gruyter|date=1985|chapter=XV 2.1.3|edition= 33rd|{{isbn|3-11-012641-9}} }}</ref> The two most common allotropes are white phosphorus and red phosphorus.<ref name="Abundance">[http://www.ptable.com/#Property/Abundance/Crust Abundance]. ptable.com</ref>

Violet phosphorus is a form of phosphorus that can be produced by day-long annealing of red phosphorus above 550&nbsp;°C, when phosphorus was recrystallised from molten lead, a red/purple form is obtained, sometimes known as "Hittorf's phosphorus" (or violet or α-metallic phosphorus).<ref name=Berger>{{Cite book|url=https://archive.org/details/semiconductormat0000berg|page=84]|title=Semiconductor materials|author=Berger, L. I.|publisher =CRC Press| date= 1996|
isbn=0-8493-8912-7}}</ref>

"It would appear that violet phosphorus is a [[w:polymer|polymer]] of high relative molecular mass, which on heating breaks down into P<sub>2</sub> molecules. On cooling, these would normally [[w:Dimer (chemistry)|dimerize]] to give P<sub>4</sub> molecules (i.e. white phosphorus) but, [[w:in vacuo|in vacuo]], they link up again to form the polymeric violet allotrope."<ref name=AllotropesofPhosphorus>{{ cite web
|title=Allotropes of phosphorus
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=20 March 2013
|url=http://en.wikipedia.org/wiki/Allotropes_of_phosphorus
|accessdate=2013-03-20 }}</ref>

Phosphorus is an important component in steel production, in the making of phosphor bronze, and in many other related products.<ref>{{cite book|title=Sustainable Phosphorus Management: A Global Transdisciplinary Roadmap|publisher=Springer Science & Business Media |editor=Roland W. Scholz |editor2=Amit H. Roy |editor3=Fridolin S. Brand |editor4=Deborah Hellums |editor5=Andrea E. Ulrich|isbn=978-9400772502|page=175|date=2014-03-12}}</ref><ref>{{cite book|title=Encyclopedia and Handbook of Materials, Parts and Finishes|publisher=CRC Press |author=Mel Schwartz|isbn=978-1138032064|date=2016-07-06}}</ref>

Phosphorus is added to metallic copper during its smelting process to react with oxygen present as an impurity in copper and to produce phosphorus-containing copper (CuOFP) alloys with a higher hydrogen embrittlement resistance than normal copper.<ref>{{cite book|title=Copper and Copper Alloys|publisher=ASM International |editor=Joseph R. Davisz|{{isbn|0871707268}}|page=181|date=January 2001}}</ref>
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==Platinums==
[[Image:Platinum-nugget.jpg|thumb|right|250px|This is a native platinum nugget, locality Kondyor mine, Khabarovsk Krai, Russia. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|fairuse}}]]
[[Image:Platinum crystals.jpg|thumb|left|250px|Crystals of pure platinum were grown by gas phase transport. Credit: [[c:user:Periodictableru|Periodictableru]].{{tlx|free media}}]]
[[Image:Platinum spectrum visible.png|thumb|center|400px|Platinum spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Platinum can also occur as nuggets such as the one imaged on the right from Russia.

"Terrestrial iron-free rhodium-bearing platinum with the composition of Pt<sub>0.68</sub>Rh<sub>0.32</sub> in association with platinum-bearing rhodium Rh<sub>0.57</sub>Pt<sub>0.43</sub> [...] was originally discovered in heavy fractions from basic rocks (norite, gabbro, and anorthosite) in the upper zone of the layered Stillwater intrusion (Montana, United States) [2]."<ref name=Gornostaeva>{{ cite journal
|author=T. A. Gornostaeva
|author2=P. M. Kartashov
|author3=A. V. Mokhov
|author4=O. A. Bogatikov
|title=Native Rhodium-Bearing Ferroplatinum in a Lunar Regolith Sample from the Mare Fecunditatis
|journal=Doklady Earth Sciences
|year=2012
|volume=444
|issue=2
|pages=770-2
|url=http://link.springer.com/article/10.1134/S1028334X12060220#/page-1
|arxiv=
|bibcode=
|doi=10.1134/S1028334X12060220
|pmid=
|accessdate=2015-11-04 }}</ref>

In nickel and copper deposits, platinum-group metals occur as sulfides (e.g., (Pt,Pd)S), tellurides (e.g., PtBiTe), antimonides (PdSb), and arsenides (e.g. PtAs<sub>2</sub>), and as end alloys with nickel or copper.
{{clear}}

==Cooperites==
[[Image:Cooperite.jpg|thumb|right|250px|Outstanding specimen is the extremely rare platinum mineral cooperite (PtS). Credit: [[c:user:David Hospital|David Hospital]].{{tlx|free media}}]]
This specimen on the right is a single nugget from Tulameen River, Princeton, British Columbia, Canada.
{{clear}}

==Plutoniums==
[[Image:Muromontite.png|thumb|right|250px|This is a sample of the naturally occurring mineral muromontite. Credit: eBay seller rubbleshop.{{tlx|fairuse}}]]
[[Image:Plutonium spectrum visible.png|thumb|center|400px|Plutonium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
"The sample [on the right] representing plutonium is the naturally occurring mineral muromontite, which is a mixture of uranium and beryllium. [The] alpha particles from the decay of uranium are captured by the beryllium atoms, which in turn release neutrons. [...] In the case of this sample, [...] the neutrons are in turn re-captured by the uranium, which then undergoes further decay and is transformed into plutonium. The result is that this mineral contains the highest known naturally occurring concentration of plutonium."<ref name=GrayPlutonium>{{ cite web
|author=Theodore W. Gray
|title=Natural plutonium-containing mineral
|publisher=Periodic Table.com
|location=
|date=19 October 2002
|url=http://periodictable.com/Items/094.1/index.html
|accessdate=2015-11-05 }}</ref>

Gallium, aluminium, americium, scandium and cerium can stabilize the δ phase of plutonium for room temperature, silicon, indium, zinc and zirconium allow formation of metastable δ state when rapidly cooled, high amounts of hafnium, holmium and thallium also allows some retention of the δ phase at room temperature, but nNeptunium is the only element that can stabilize the α phase at higher temperatures.<ref name=Hecker>{{cite journal
|first = Siegfried S.
|last = Hecker
|title = Plutonium and its alloys: from atoms to microstructure
|journal = Los Alamos Science
|volume = 26
|date = 2000
|pages = 290–335
|accessdate = February 15, 2009
|url = https://web.archive.org/web/20090224204042/http://www.fas.org/sgp/othergov/doe/lanl/pubs/00818035.pdf }}</ref>
{{clear}}

==Poloniums==
[[Image:Polonium Halo in Biotite.png|thumb|right|250px|This photograph shows a <sup>210</sup>Po halo in biotite from the Buckhorn pegmatite. Credit: Lorence G. Collins.{{tlx|fairuse}}]]
[[Image:Uranium roll front hosted in Dakota Sandstone near Denver, Colorado.jpg|thumb|left|250px|Uranium roll front occurs in quartzose sandstone in the Cretaceous of Colorado, USA. Credit: [https://www.flickr.com/people/47445767@N05 James St. John].{{tlx|free media}}]]
[[Image:Radioactive decay halos along crack.png|thumb|right|250px|This photo shows a fracture in biotite in which migrating <sup>210</sup>Po and/or <sup>210</sup>Pb ions have created damage to the biotite lattice parallel to the fracture. Credit: Lorence G. Collins.{{tlx|fairuse}}]]
[[Image:Polonium spectrum visible.png|thumb|center|400px|Polonium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
α-Po crystallizes in a simple cubic lattice.<ref name=CST>{{ cite web
|author=CST
|title=The Simple Cubic Lattice
|publisher=The Naval Research Laboratory
|location=Washington, DC USA
|date=20 November 2000
|url=https://web.archive.org/web/20010204004800/http://cst-www.nrl.navy.mil/lattice/struk/a_h.html
|accessdate=2015-08-27 }}</ref>

Native polonium may occur in minerals like pitchblende due to the decay of uranium. But, when the uranium is chemically bound, the polonium is likely to be also.

β-Po has a rhombohedral (trigonal) crystal structure.<ref name=CSTPo>{{ cite web
|author=CSTPo
|title=The A_i (beta Po) Structure
|publisher=The Naval Research Laboratory
|location=Washington, DC USA
|date=20 November 2000
|url=https://web.archive.org/web/20010204004200/http://cst-www.nrl.navy.mil/lattice/struk/a_i.html
|accessdate=2015-08-27 }}</ref>

"Solid diorite and gabbro rock, which had previously crystallized from magma, has been subjected to repeated cataclasis and recrystallization. This has happened without melting; and the cataclasis provided openings for the introduction of uranium-bearing fluids and for the modification of these rocks to granite by silication and cation deletion."<ref name=Collins1997>{{ cite web
|author=Lorence G. Collins
|title=Polonium Halos and Myrmekite in Pegmatite and Granite
|publisher=California State University, Northridge
|location=Northridge, California USA
|date=3 February 1997
|url=http://scholarworks.csun.edu/bitstream/handle/10211.2/2980/CollinsLorence19970203_08.pdf?sequence=1
|accessdate=2015-08-27 }}</ref>

"In uranium ore-fields the extra uranium provides an abundant source of inert radon gas; and it is this gas that diffuses in ambient fluids so that incipient biotite and fluorite crystallization is exposed to it. Radon (<sup>222</sup>Rn) decays and Po isotopes nucleate in the rapidly growing biotite (and fluorite) crystals whence they are positioned to produce the Po halos."<ref name=Collins1997/>

On the lower right is a photograph showing radioactive decay halos along a crack in biotite.

On the left is an example of groundwater incursion that has moved through a nearby fault. The groundwater has picked up dissolved uranium compounds and moved downward through adjacent porous sandstones. Uraninite then precipitated around a tongue of groundwater, resulting in the roll front seen in the image on the left.
{{clear}}

==Potassiums==
[[Image:Phase diagram of potassium (1975).png|thumb|left|250px|This is a pressure-temperature phase diagram for potassium. Credit: David A. Young, ERDA.{{tlx|fairuse}}]]
[[Image:Potassium.JPG|right|thumb|300px|Cut potassium (kalium) pieces show metallic silver color. Credit: [[c:user:Dnn87|Dennis s.k]].{{tlx|free media}}]]
[[Image:Potassium flame.png|thumb|center|150px|The image shows the color of potassium in a natural gas burner. Credit: SciencePhoto.
{{tlx|fairuse}}]]
[[Image:Potassium spectrum visible.png|thumb|center|400px|This is a potassium emission-line spectrum over the range 400 nm - 700 nm. Credit: [[c:User:McZusatz|McZusatz]].{{tlx|free media}}]]
As indicated in the phase diagram on the left, potassium occurs in a bcc (α-K) phase from room temperature up to melting.

Native potassium does not appear to occur on the Earth's surface.

"The group [of potassium lines] at λλ 535, 510, and 495 Å showed no trace of structure even in an arc of but half an ampere."<ref name=Nutting>{{ cite journal
|author=P. G. Nutting
|title=Line Structure. I.
|journal=The Astrophysical Journal
|month=January
|year=1906
|volume=23
|issue=1
|pages=64-78
|url=
|arxiv=
|bibcode=1906ApJ....23...64N
|doi=10.1086/141302
|pmid=
|accessdate=2013-01-24 }}</ref>
{{clear}}

==Praseodymiums==
[[Image:Praseodymium spectrum visible.png|thumb|center|400px|Praseodymium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Po-BeO mixtures or alloys used as neutron sources are a neutron trigger or initiator for nuclear weapons<ref name=Emsley2001/><ref name=Rhodes>{{cite book| author = Rhodes, Richard| title = Dark Sun: The Making of the Hydrogen Bomb| publisher = Walker & Company| location = New York| date = 2002| pages = 187–188]| {{isbn|978-0-684-80400-2}}| url = https://archive.org/details/darksunmakingofh00rhod/page/187 }}</ref> and for inspections of oil wells.

The polonide of praseodymium (PrPo) melts at 1250&nbsp;°C, and that of thulium (TmPo) melts at 2200&nbsp;°C.<ref name=Greenwood/> PbPo is one of the very few naturally occurring polonium compounds, as polonium alpha decays to form lead.<ref name=Weigel>{{cite journal |last1=Weigel |first1=F. |date=1959 |title=Chemie des Poloniums |journal=Angewandte Chemie |volume=71 |pages=289–316 |doi=10.1002/ange.19590710902 |issue=9|bibcode=1959AngCh..71..289W }}</ref>
{{clear}}

==Promethiums==
[[Image:Promethium spectrum visible.png|thumb|center|400px|Promethium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]

{| Class = "wikitable" style = "text-align: center"
! Formula
! symmetry
! space group
! No
! Pearson symbol
! ''a'' (pm)
! ''b'' (pm)
! ''c'' (pm)
! ''Z''
! density, <br/>g/cm<sup>3</sup>
|-
| α-Pm
| Close-packing of equal spheres (dhcp)<ref name=Pallmer>{{cite journal|doi=10.1016/0022-5088(71)90101-9|title=The crystal structure of promethium|year=1971|last1=Pallmer|first1=P. G.|last2=Chikalla|first2=T. D.|journal=Journal of the Less Common Metals|volume=24|issue=3|pages=233}}</ref><ref name=Gschneidner>{{cite book |editor=Lide, D. R. |author=Gschneidner Jr., K.A. |title=Physical Properties of the rare earth metals, In: ''CRC Handbook of Chemistry and Physics'' |edition=86th |location=Boca Raton, FL |publisher=CRC Press |year=2005 |{{isbn|978-0-8493-0486-6}} |accessdate=2012-06-20 |url=https://link.springer.com/article/10.1007/BF03029283 |archive-date=2012-09-18 }}</ref>
| P6<sub>3</sub>/mmc
| 194
| hP4
| 365
| 365
| 1165
| 4
| 7.26
|-
| β-Pm
| Cubic crystal system (bcc)<ref name=Gschneidner/>
| Fm{{overline|3}}m
| 225
| cF4
| 410
| 410
| 410
| 4
| 6.99
|}
{{clear}}

==Protactiniums==
[[Image:Protactinium.jpg|right|thumb|300px|Protactinium crystal, prepared by the van Arkel (chemical vapour transport) process. Credit: The Actinide Group, the [http://itu.jrc.ec.europa.eu/ Institute for Transuranium Elements].{{tlx|fairuse}}]]
[[Image:Protactinium-233.jpg|thumb|left|250px|This sample of Protactinium-233 (dark circular area in the photo) was photographed in the light from its own radioactive emission (the lighter area) at the National Reactor Testing Station in Idaho. Credit: [https://www.flickr.com/people/37916456@N02 ENERGY.GOV].{{tlx|free media}}]]
[[Image:Protactinium spectrum visible.png|thumb|center|400px|Protactinium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Protactinium is one of the rarest and most expensive naturally occurring elements, found in the form of two isotopes – <sup>231</sup>Pa and <sup>234</sup>Pa, with the isotope <sup>234</sup>Pa occurring in two different energy states: nearly all natural protactinium is protactinium-231, an alpha emitter formed by the decay of uranium-235, whereas the beta radiating protactinium-234 is produced as a result of [[:File:Decay chain(4n+2, Uranium series).PNG|uranium-238 decay]]. Nearly all uranium-238 (99.8%) decays first to the shorter-lived <sup>234m</sup>Pa isomer.<ref name=ANL>{{ cite web
|title=Protactinium, Human Health Fact Sheet
|url=https://web.archive.org/web/20080307023843/http://www.ead.anl.gov/pub/doc/protactinium.pdf
|accessdate=7 March 2008
|publisher=Argonne National Laboratory
|date=August 2005 }}</ref>
{{clear}}

==Radiums==
[[Image:Radium226.jpg|thumb|right|250px|Radium electroplated on a very small sample of copper foil and covered with polyurethane to prevent reaction with the air. Credit: [[c:user:Grenadier-commonswiki|grenadier]].{{tlx|free media}}]]
[[Image:Radium spectrum visible.png|thumb|left|400px|Radium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Radium flame.png|thumb|center|150px|The image shows the color of radium in a natural gas burner. Credit: Alan Crooks.
{{tlx|fairuse}}]]
"Solid radium is bcc at room temperature. Radium melts at 973 K.<sup>63</sup>"<ref name=Young>{{ cite book
|author=David A. Young
|title=Phase Diagrams of the Elements
|publisher=Lawrence Livermore Laboratory
|location=University of California, Livermore, California USA
|date=11 September 1975
|editor=
|pages=70
|url=http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/07/255/7255152.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|isbn=
|accessdate=2015-08-26 }}</ref>

Radium oxide (RaO) has not been characterized well past its existence, despite oxides being common compounds for the other alkaline earth metals.
{{clear}}

==Radons==
{{main|Chemicals/Radons}}

==Rheniums==
[[Image:Native rhenium 2.png|thumb|right|250px|This is an image of the first find of native rhenium in the transitional clay layer at the Cretaceous/Paleogene boundary in the Gams Section. Credit: A. F. Grachev, S. E. Borisovsky, and A. V. Grigor’eva.{{tlx|fairuse}}]]
[[Image:Rhenium single crystal bar and 1cm3 cube.jpg|thumb|left|250px|Three high-purity forms of rhenium metal are shown: a single crystal (99.999% pure) made by the floating-zone process, an e-beam remelted bar (99.995% pure), and a 1 cm<sup>3</sup> cube (99.99% pure) for comparison. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Rhenium spectrum visible.png|thumb|center|400px|Rhenium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
"Native rhenium was first discovered in the Earth's crust in wolframites from a rare metal deposit in the Transbaikal region [1]. [...] The study of the lunar regolith from two sites revealed native rhenium particles with different morphological features: irregular dense particles from Mare Fecunditatis and spheroidal particles from Mare Crisium. The origin of particles (less than 10 µm in size) is assigned to exhalative processes [2]. Among the extraterrestrial objects, native rhenium was found in Ni-iron and silicates from the Allende meteorite [3]."<ref name=Grachev>{{ cite journal
|author=A. F. Grachev
|author2=S. E. Borisovsky
|author3=A. V. Grigor’eva
|title=The first find of native rhenium in the transitional clay layer at the Cretaceous/Paleogene boundary in the Gams Section (eastern Alps, Austria)
|journal=Doklady Earth Sciences
|date=October 2008
|volume=422
|issue=1
|pages=1065-7
|url=http://link.springer.com/article/10.1134/S1028334X08070131
|arxiv=
|bibcode=
|doi=10.1134/S1028334X08070131
|pmid=
|accessdate=2015-11-04 }}</ref>


"Solid radium is bcc at room temperature. Radium melts at 973 K.<sup>63</sup>"<ref name=Young>{{ cite book
|author=David A. Young
|title=Phase Diagrams of the Elements
|publisher=Lawrence Livermore Laboratory
|location=University of California, Livermore, California USA
|date=11 September 1975
|editor=
|pages=70
|url=http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/07/255/7255152.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|isbn=
|accessdate=2015-08-26 }}</ref>

"Instrumental neutron activation analyses of Kilauean aerosols collected in 1984 show Ir:Au:Re ratios of 1:12:2000 normalized to CI chondrites. The large Re enrichment in these volcanic aerosols may explain the 3 to 15-fold Re excess, relative to chondritic, in the observed siderophile element signature of the Cretaceous-Tertiary boundary clay layer.<sup>2,3</sup> Strong evidence exists that an impact of an extraterrestrial body on the Earth caused mass extinctions at the end of the Cretaceous period.<sup>4,5</sup> ... A Kilauean aerosol contribution of only 0.01 % of the chondritic component in the boundary clay layer would produce the observed Re enrichments."<ref name=Hildebrand>{{ cite journal
|author=A. R. Hildebrand
|author2=W. V. Boynton
|author3=W. H. Zoller
|title=Rhenium Enriched Kilauea Volcano Aerosols: Evidence for a Volcanogenic Component in the K/T Boundary Clay Layer
|journal=Bulletin of the American Astronomical Society
|month=June
|year=1984
|volume=16
|issue=06
|pages=679
|url=http://adsabs.harvard.edu/abs/1984BAAS...16..679H
|arxiv=
|bibcode=1984BAAS...16..679H
|doi=
|pmid=
|accessdate=2014-01-10 }}</ref>
{{clear}}

==Rhodiums==
[[Image:Native rhodium.jpg|thumb|right|250px|This image of microbreccia contains rhodium-bearing ferroplatinum. Credit: T. A. Gornostaeva, P. M. Kartashov, A. V. Mokhov, and O. A. Bogatikov.{{tlx|fairuse}}]]
[[Image:Rhodium powder pressed melted.jpg|thumb|left|250px|Rhodium processing is shown: 1g powder, 1g pressed cylinder, 1 g argon arc remelted pellet. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Rhodium spectrum visible.png|thumb|center|400px|Rhodium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The image on the right contains small particles of native rhodium-bearing ferroplatinum. This sample was obtained from the lunar regolith "by the ''Luna-16'' automatic station".<ref name=Gornostaeva/>

"Terrestrial iron-free rhodium-bearing platinum with the composition of Pt<sub>0.68</sub>Rh<sub>0.32</sub> in association with platinum-bearing rhodium Rh<sub>0.57</sub>Pt<sub>0.43</sub> [...] was originally discovered in heavy fractions from basic rocks (norite, gabbro, and anorthosite) in the upper zone of the layered Stillwater intrusion (Montana, United States) [2]."<ref name=Gornostaeva/>

Naturally occurring rhodium is usually found as a free metal or as an alloy with similar metals and rarely as a chemical compound in minerals such as bowieite and rhodplumsite.

Rhodium is used as an alloying agent for hardening and improving the corrosion resistance.<ref name=Cramer>{{cite book|editor-last = Cramer|editor-first = Stephen D.|editor2-last = Covino, Jr. |editor2-first=Bernard S.|title = ASM handbook|year = 1990|publisher = ASM International|location = Materials Park, OH|{{isbn|978-0-87170-707-9}}|pages = 393–396|url = https://books.google.com/books?id=QV0sWU2qF5oC&pg=PA396}}</ref> of platinum and palladium.
{{clear}}

==Roentgeniums==

"Based on the observation of the long-lived isotopes of roentgenium, <sup>261</sup>Rg and <sup>265</sup>Rg (Z = 111, t<sub>1/2</sub> ≥ 10<sup>8</sup> y) in natural Au, an experiment was performed to enrich Rg in 99.999% Au. 16 mg of Au were heated in vacuum for two weeks at a temperature of 1127°C (63°C above the melting point of Au). The content of <sup>197</sup>Au and <sup>261</sup>Rg in the residue was studied with high resolution inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The residue of Au was 3 × 10<sup>−6</sup> of its original quantity. The recovery of Rg was a few percent. The abundance of Rg compared to Au in the enriched solution was about 2 × 10<sup>−6</sup>, which is a three to four orders of magnitude enrichment."<ref name=Marinov>{{ cite journal
|author=A. Marinov, A. Pape, D. Kolb, L. Halicz, I. Segal, N. Tepliakov and R. Brandt
|title=Enrichment of the Superheavy Element Roentgenium (Rg) in Natural Au
|journal=International Journal of Modern Physics E
|month=
|year=2011
|volume=20
|issue=11
|pages=2391-2401
|url=http://www.phys.huji.ac.il/~marinov/publications/Rg_261_arXiv_77.pdf
|arxiv=
|bibcode=
|doi=10.1142/S0218301311020393
|pmid=
|accessdate=2014-04-08 }}</ref>

The isotopes <sup>280</sup>Rg and <sup>281</sup>Rg are promising for chemical experimentation and may be produced as the granddaughters of the moscovium isotopes <sup>288</sup>Mc and <sup>289</sup>Mc respectively;<ref name="Moody">{{cite book |chapter=Synthesis of Superheavy Elements |last1=Moody |first1=Ken |editor1-first=Matthias |editor1-last=Schädel |editor2-first=Dawn |editor2-last=Shaughnessy |title=The Chemistry of Superheavy Elements |publisher=Springer Science & Business Media |edition=2nd |pages=24–8 |isbn=9783642374661|date=2013-11-30 }}</ref> their parents are the nihonium isotopes <sup>284</sup>Nh and <sup>285</sup>Nh, which have already received preliminary chemical investigations.<ref>{{cite journal |last1=Aksenov |first1=Nikolay V. |last2=Steinegger |first2=Patrick |first3=Farid Sh. |last3=Abdullin |first4=Yury V. |last4=Albin |first5=Gospodin A. |last5=Bozhikov |first6=Viktor I. |last6=Chepigin |first7=Robert |last7=Eichler |first8=Vyacheslav Ya. |last8=Lebedev |first9=Alexander Sh. |last9=Mamudarov |first10=Oleg N. |last10=Malyshev |first11=Oleg V. |last11=Petrushkin |first12=Alexander N. |last12=Polyakov |first13=Yury A. |last13=Popov |first14=Alexey V. |last14=Sabel'nikov |first15=Roman N. |last15=Sagaidak |first16=Igor V. |last16=Shirokovsky |first17=Maksim V. |last17=Shumeiko |first18=Gennadii Ya. |last18=Starodub |first19=Yuri S. |last19=Tsyganov |first20=Vladimir K. |last20=Utyonkov |first21=Alexey A. |last21=Voinov |first22=Grigory K. |last22=Vostokin |first23=Alexander |last23=Yeremin |first24=Sergey N. |last24=Dmitriev |date=July 2017 |title=On the volatility of nihonium (Nh, Z = 113) |journal=The European Physical Journal A |volume=53 |issue=158 |pages=158 |doi=10.1140/epja/i2017-12348-8|bibcode=2017EPJA...53..158A |s2cid=125849923 |url=https://www.semanticscholar.org/paper/5a07c41dfd0fc2913510dc843a5bc9a506bc92d4 }}</ref>

==Rubidiums==
[[Image:Phase diagram of rubidium (1975).png|thumb|left|250px|This is a pressure-temperature phase diagram for rubidium. Credit: David A. Young, ERDA.{{tlx|free media}}]]
[[Image:Rubidiumsample.JPG|right|thumb|250px|Rubidium metal sample is enclosed in a quartz ampule to prevent oxidation. Credit: [[cs:user:Dnn87|Dnn87]].{{tlx|free media}}]]
[[Image:Die Flammenfärbung des Rubidium.jpg|thumb|right|250px|This image shows the flame test for Rubidium. Credit: [[c:User:Didaktische.Medien|Didaktische.Medien]].{{tlx|free media}}]]
[[Image:Rubidium spectrum visible.png|center|thumb|400px|Rubidium emission spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The pressure-temperature diagram on the left shows that rubidium is bcc (α-Rb) from room temperature through melting.

Native rubidium does not appear to occur on the Earth's surface.
{{clear}}

==Rutheniums==
[[Image:Native Ruthenium from Verkneivinsk.png|thumb|right|250px|This is a piece of native ruthenium from Verkhneivinsk, Neiva river, Sverdlovskaya Oblast', Middle Urals, Urals Region, Russia. Credit: Hudson Institute of Mineralogy.{{tlx|fairuse}}]]
[[Image:Ruthenium a half bar.jpg|thumb|left|250px|One half of a high-purity (99.99%), electron-beam-remelted ruthenium bar is shown. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Ruthenium crystals.jpg|thumb|center|250px|Gas phase grown crystals of ruthenium metal are shown. Credit: [[c:user:Periodictableru|Periodictableru]].{{tlx|free media}}]]
[[Image:Ruthenium spectrum visible.png|thumb|center|400px|Ruthenium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
The piece of native ruthenium in the image on the right contains some iridium. It is from Verkhneivinsk, Neiva river, Sverdlovskaya Oblast', Middle Urals, Urals Region, Russia.

A minor application for ruthenium is in platinum alloys. A ruthenium-molybdenum alloy is known to be superconductive at temperatures below 10.6 K.<ref name=Haynes2016>Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. {{ISBN|9781498754293}}.</ref> The composition of the mined platinum group metal (PGM) mixtures varies widely, depending on the geochemical formation. For example, the PGMs mined in South Africa contain on average 11% ruthenium while the PGMs mined in the former USSR contain only 2% (1992).<ref>{{cite book|url = https://books.google.com/books?id=Wm6QMRaX9C4C&pg=PA69|page =69|{{isbn|978-0-87335-100-3}}|editor = Hartman, H. L.|editor2 = Britton, S. G.|date = 1992|publisher = Society for Mining, Metallurgy, and Exploration|location = Littleton, Colo.|title = SME mining engineering handbook}}</ref><ref>{{cite journal |last1=Harris |first1=Donald C. |last2=Cabri |first2=Louis J. |title=The nomenclature of the natural alloys of osmium, iridium and ruthenium based on new compositional data of alloys from world-wide occurrences |journal=The Canadian Mineralogist |date=1 August 1973 |volume=12 |issue=2 |pages=104–112
|url=https://pubs.geoscienceworld.org/canmin/article-abstract/12/2/104/10913/The-nomenclature-of-the-natural-alloys-of-osmium }}</ref>
{{clear}}

==Rutherfordiums==

Rutherfordium was synthesized by bombarding a californium-249 target with carbon-12 ions and measured the alpha decay of <sup>257</sup>Rf, correlated with the daughter decay of nobelium-253:<ref name=Ghiorso>{{cite journal |doi = 10.1103/PhysRevLett.22.1317 |title = Positive Identification of Two Alpha-Particle-Emitting Isotopes of Element 104 |date = 1969 |last1 = Ghiorso |first1 = A. |last2 = Nurmia |first2=M. |journal = Physical Review Letters |volume = 22 |issue = 24 |pages = 1317–1320 |bibcode=1969PhRvL..22.1317G|last3 = Harris |first3 = J. |last4 = Eskola |first4 = K. |last5 = Eskola |first5 = P. |url = https://cloudfront.escholarship.org/dist/prd/content/qt3fm666nq/qt3fm666nq.pdf }}</ref>
:{{nuclide|californium|249}} + {{nuclide|carbon|12}} → {{nuclide|rutherfordium|257}} + 4 {{SubatomicParticle|neutron}}

Rutherfordium is the parent of K-alpha X-rays in the elemental signature of the <sup>257</sup>Rf decay product, nobelium-253.<ref name=Bemis>{{cite journal |doi =10.1103/PhysRevLett.31.647 |title =X-Ray Identification of Element 104 |date =1973 |author =Bemis, C. E. |journal =Physical Review Letters |volume =31 |issue =10 |pages =647–650 |bibcode=1973PhRvL..31..647B |last2 =Silva |first2 =R. |last3 =Hensley |first3 =D. |last4 =Keller |first4 =O. |last5 =Tarrant |first5 =J. |last6 =Hunt |first6 =L. |last7 =Dittner |first7 =P. |last8 =Hahn |first8 =R. |last9 =Goodman |first9 =C. }}</ref>

==Samariums==
[[Image:Samarium-2.jpg|thumb|right|250px|Ultrapure sublimated samarium, 2 grams, is shown. Credit: Unknown author.{{tlx|free media}}]]
[[Image:Samarium spectrum visible.png|thumb|center|400px|Samarium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Samarium occurs in concentration up to 2.8% in several minerals including cerite, gadolinite, samarskite, monazite and bastnäsite.

{| Class = "wikitable collapsible collapsed" style = "text-align: center"
|-
! Formula
! color
! symmetry
! space group
! No
! Pearson symbol
! ''a'' (pm)
! ''b'' (pm)
! ''c'' (pm)
! ''Z''
! density, <br/>g/cm<sup>3</sup>
|-
| Sm
| silvery
| trigonal<ref name="sm">{{cite journal|doi=10.1016/0022-5088(85)90294-2|last1=Shi|first1=N.|date=1985|page=21|volume=113|journal=Journal of the Less Common Metals|last2=Fort|first2=D.|title=Preparation of samarium in the double hexagonal close packed form|issue=2}}</ref>
| R{{overline|3}}m
| 166
| hR9
| 362.9
| 362.9
| 2621.3
| 9
| 7.52
|-
| Sm
| silvery
| hexagonal<ref name="sm" />
| P6<sub>3</sub>/mmc
| 194
| hP4
| 362
| 362
| 1168
| 4
| 7.54
|-
| Sm
| silvery
| tetragonal<ref name="sm2">{{cite journal|doi=10.1016/0375-9601(91)90346-A|last1=Vohra|date=1991|first1=Y.|page=89|volume=158|issue=1–2|journal=Physics Letters A |title=A new ultra-high pressure phase in samarium|bibcode = 1991PhLA..158...89V|last2=Akella|first2=Jagannadham|last3=Weir|first3=Sam|last4=Smith|first4=Gordon S. |url=https://zenodo.org/record/1258493}}</ref>
| I4/mmm
| 139
| tI2
| 240.2
| 240.2
| 423.1
| 2
| 20.46
|-
| SmO
| golden
| cubic<ref name="smox">{{cite journal|last1=Leger|first1=J.|last2=Yacoubi|first2=N.|last3=Loriers|first3=J.|title=Synthesis of rare earth monoxides|journal=Journal of Solid State Chemistry|volume=36|page=261|date=1981 |doi=10.1016/0022-4596(81)90436-9|issue=3|bibcode = 1981JSSCh..36..261L }}</ref>
| Fm{{overline|3}}m
| 225
| cF8
| 494.3
| 494.3
| 494.3
| 4
| 9.15
|-
| SmN
|
| cubic<ref name="smn">{{cite journal|last1=Brown|first1=R.|title=Composition limits and vaporization behaviour of rare earth nitrides|journal=Journal of Inorganic and Nuclear Chemistry|volume=36|page=2507|date=1974 |doi=10.1016/0022-1902(74)80462-8|issue=11|last2=Clark|first2=N. J.}}</ref>
| Fm{{overline|3}}m
| 225
| cF8
| 357
| 357
| 357
| 4
| 8.48
|-
| SmP
|
| cubic<ref name="smp">{{cite journal|last1=Meng|first1=J.|title=Studies on the electrical properties of rare earth monophosphides|journal=Journal of Solid State Chemistry|volume=95|page=346|date=1991 |doi=10.1016/0022-4596(91)90115-X|issue=2|bibcode = 1991JSSCh..95..346M|last2=Ren|first2=Yufang }}</ref>
| Fm{{overline|3}}m
| 225
| cF8
| 576
| 576
| 576
| 4
| 6.3
|-
| SmAs
|
| cubic<ref name="smas">{{cite journal|last1=Beeken|first1=R.|last2=Schweitzer|first2=J.|title=Intermediate valence in alloys of SmSe with SmAs|journal=Physical Review B|volume=23|page=3620|date=1981|doi=10.1103/PhysRevB.23.3620|issue=8|bibcode = 1981PhRvB..23.3620B }}</ref>
| Fm{{overline|3}}m
| 225
| cF8
| 591.5
| 591.5
| 591.5
| 4
| 7.23
|-
|}
{{clear}}

==Scandiums==
[[Image:Scandium spectrum visible.png|center|thumb|400px|Scandium emission spectrum is from 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Ultrapure crystalline scandium, 5 grams.jpg|right|thumb|250px|Scandium is the first transition metal and the first rare earth element. Credit: Hi-Res Images of Chemical Elements.{{tlx|free media}}]]
Scandium is the first transition metal and the first rare earth element, the latter also includes yttrium and the lanthanoids. The ignoble light metal has only a few applications, because its chemistry isn't so complex and it also is rather expensive. It is used in high-quality, light alloys, e.g., for frames of racing bicycles.

Scandium (Sc II) has an absorption band, 424.683±1.0 nm, with an excitation potential of 0.31 eV.<ref name=Sadakane>{{ cite journal
|author=Kozo Sadakane
|author2=Minoru Ueta
|title=Abundance Analysis of Sirius in the Blue-Violet Region
|journal=Publications of the Astronomical Society of Japan
|month=August
|year=1989
|volume=41
|issue=2
|pages=279-88
|url=
|arxiv=
|bibcode=1989PASJ...41..279S
|doi=
|pmid=
|accessdate=2012-02-18 }}</ref>

Metallic scandium is used in aluminium alloysis for strengthening with as little as 0.5% scandium.<ref name=Burrell>Burrell, A. Willey Lower "Aluminum scandium alloy" {{US patent|3,619,181}} issued on November 9, 1971.</ref><ref name=Zakharov>{{cite journal|title= Effect of Scandium on the Structure and Properties of Aluminum Alloys|journal= Metal Science and Heat Treatment|volume= 45|date= 2003|page= 246|doi= 10.1023/A:1027368032062|first= V. V.|last= Zakharov|issue= 7/8|bibcode= 2003MSHT...45..246Z|s2cid= 135389572}}</ref>

The alloy {{chem|Al|20|Li|20|Mg|10|Sc|20|Ti|30}} is as strong as titanium, light as aluminium, and hard as some ceramics.<ref name=Youssef>{{Cite journal |doi = 10.1080/21663831.2014.985855|title = A Novel Low-Density, High-Hardness, High-entropy Alloy with Close-packed Single-phase Nanocrystalline Structures|journal = Materials Research Letters|volume = 3|issue = 2|pages = 95–99|year = 2015|last1 = Youssef|first1 = Khaled M.|last2 = Zaddach|first2 = Alexander J.|last3 = Niu|first3 = Changning|last4 = Irving|first4 = Douglas L.|last5 = Koch|first5 = Carl C.|doi-access = free}}</ref>

"Neutron activation analysis was used to deterimne the total [lanthanum] La and [scandium] Sc content of three soils developed from loess-capped glacial till. The profiles were classified as Gray-Brown Podzolics (Hapludalfs) overlying paleosols developed in Rockain till. The total La content in the less than 250µ fraction of these soils ranged from 18.1 to 37.1 ppm, with an average content of 23.7 ppm in the loess and 28.5 ppm in the glacial till. Total Sc in the soils ranged from 5.1 to 10.9 ppm with average contents of 6.5 and 9.0 ppm in the loess and glacial till, respectively. Translocation by pedogenic processes was indicated by the accumulation of these elements in the argillic B horizons. Correlation coefficients of La and Sc with clay percentages in the profiles were 0.79 and 0.88, respectively."<ref name=Kline>{{ cite journal
|author=J. R. Kline
|author2=J. E. Foss
|author3=S. S. Brar
|title=Lanthanum and Scandium Distribution in Three Glacial Soils of Western Wisconsin
|journal=Soil Science Society of America Journal
|month=March
|year=1969
|volume=33
|issue=2
|pages=287-91
|url=https://dl.sciencesocieties.org/publications/sssaj/abstracts/33/2/SS0330020287
|arxiv=
|bibcode=
|doi=10.2136/sssaj1969.03615995003300020034x
|pmid=
|accessdate=2014-10-01 }}</ref>
{{clear}}

==Seaborgiums==

Alpha emission (α), spontaneous fission (SF) and electron capture (EC) are decay modes of seaborgium.
{| class="wikitable sortable"
|+List of seaborgium isotopes
! Isotope<br> !! Half-life<br><ref name="nuclidetable">{{cite web |url=http://www.nndc.bnl.gov/chart/reCenter.jsp?z=107&n=163 |title=Interactive Chart of Nuclides |publisher=Brookhaven National Laboratory |author=Sonzogni, Alejandro |location=National Nuclear Data Center |access-date=2008-06-06 |archive-date=2018-06-12 |archive-url=https://web.archive.org/web/20180612141714/http://www.nndc.bnl.gov/chart/reCenter.jsp?z=107&n=163 |url-status=dead }}</ref><ref name="periodictable">{{cite web |url=http://periodictable.com/ |title=The Photographic Periodic Table of the Elements |author=Gray, Theodore |date=2002–2010 |work=periodictable.com |access-date=16 November 2012}}</ref> !! Decay<br>mode<ref name="nuclidetable" /><ref name="periodictable" /> !! Discovery<br>year !! Reaction
|-
|<sup>258</sup>Sg||{{sort|00000003|3 ms}}||SF||1994||<sup>209</sup>Bi(<sup>51</sup>V,2n)
|-
|<sup>259</sup>Sg||{{sort|00006|600 ms}}||α||1985||<sup>207</sup>Pb(<sup>54</sup>Cr,2n)
|-
|<sup>260</sup>Sg||{{sort|00000004|4 ms}}||SF, α||1985||<sup>208</sup>Pb(<sup>54</sup>Cr,2n)
|-
|<sup>261</sup>Sg||{{sort|00002|200 ms}}||α, EC, SF||1985||<sup>208</sup>Pb(<sup>54</sup>Cr,n)
|-
|<sup>261m</sup>Sg||{{sort|00000000092|92 μs}}||IT||2009||<sup>208</sup>Pb(<sup>54</sup>Cr,n)
|-
|<sup>262</sup>Sg||{{sort|0000007|7 ms}}||SF, α||2001||<sup>270</sup>Ds(—,2α)
|-
|<sup>263</sup>Sg||{{sort|0001|1 s}}||α||1994||<sup>271</sup>Ds(—,2α)
|-
|<sup>263m</sup>Sg||{{sort|000012|120 ms}}||α, SF||1974||<sup>249</sup>Cf(<sup>18</sup>O,4n)
|-
|<sup>264</sup>Sg||{{sort|0000037|37 ms}}||SF||2006||<sup>238</sup>U(<sup>34</sup>Si,4n)
|-
|<sup>265</sup>Sg||{{sort|0008|8 s}}||α||1993||<sup>248</sup>Cm(<sup>22</sup>Ne,5n)
|-
|<sup>265m</sup>Sg||{{sort|00162|16.2 s}}||α||1993||<sup>248</sup>Cm(<sup>22</sup>Ne,5n)
|-
|<sup>266</sup>Sg||{{sort|000036|360 ms}}||SF||2004||<sup>270</sup>Hs(—,α)
|-
|<sup>267</sup>Sg||{{sort|0084|1.4 min}}||SF, α||2004||<sup>271</sup>Hs(—,α)
|-
|<sup>269</sup>Sg||{{sort|0840|14 min}}||α||2010||<sup>285</sup>Fl(—,4α)
|-
|<sup>271</sup>Sg||{{sort|0144|2.4 min}}||α||2003||<sup>287</sup>Fl(—,4α)
|}
{{clear}}

==Seleniums==
[[Image:Selenium native.jpg|thumb|right|Selenium (native) with pen for scale is from the mineral collection of Brigham Young University Department of Geology, Provo, Utah. Credit: Andrew Silver, USGS.{{tlx|free media}}]]
[[Image:Selenium in sandstone Westwater Canyon Section 23 Mine Grants, New Mexico.jpg|thumb|left|200px|The dark gray mineral in the yellow sandstone is native selenium. Credit: [https://www.flickr.com/people/47445767@N05 James St. John].{{tlx|free media}}]]
[[Image:Native selenium.jpg|thumb|center|250px|These are native selenium needles from Katharine mine, Radvanice, Czech Republic. Credit: Asahi.{{tlx|fairuse}}]]
[[Image:SeBlackRed.jpg|thumb|right|250px|Black, glassy amorphous (with thin layer of grey selenium) and red amorphous selenium are allotropes of selenium. Credit: W. Oelen.{{tlx|free media}}]]
[[Image:Selenium spectrum visible.png|center|thumb|400px|Selenium emission spectrum for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
On the right is a photograph of native selenium from the mineral collection of Brigham Young University Department of Geology, Provo, Utah.

The image on the left shows dark gray selenium in sandstone from Westwater Canyon Section 23 Mine Grants, New Mexico.

In the center image are native selenium needles from Katharine mine, Radvanice, Czech Republic.

Allotropes of selenium are amorphous, brick-red (α, β,<ref>{{cite web |title=β –Se (Al ) Structure: A_mP32_14_8e |url=http://aflowlib.org/prototype-encyclopedia/A_mP32_14_8e.html |website=Encyclopedia of Crystallographic Prototypes}}</ref><ref>{{cite web |title=β –Se (Al ) Structure: A_mP32_14_16e |url=http://aflowlib.org/prototype-encyclopedia/A_mP64_14_16e.html |website=Encyclopedia of Crystallographic Prototypes}}</ref> and γ<ref name=Foss>{{cite journal |last1=Olav Foss and Vitalijus Janickis |title=Crystal structure of γ-monoclinic selenium |journal=Journal of the Chemical Society, Dalton Transactions |date=1980 |issue=4 |pages=624–627 |doi=10.1039/DT9800000624}}</ref>) powders, black, vitreous beads,<ref name=House>{{cite book |title=Inorganic chemistry |first=James E. |last=House |publisher=Academic Press |year=2008 |isbn=978-0-12-356786-4 |page=524}}</ref> and gray selenium.

Selenium is used with bismuth in brasses to replace lead.<ref name=Davis>{{cite book|url= https://books.google.com/books?id=sxkPJzmkhnUC&pg=PA91|page= 91|title= Copper and Copper Alloys|{{isbn|978-0-87170-726-0}}|last1= Davis|first1=Joseph R.|date= 2001 |publisher= ASM Int. }}</ref><!--https://books.google.com/books?id=SZ1RAAAAMAAJ&pg=PA378--> Like lead and sulfur, selenium improves the machinability of steel at concentrations around 0.15%.<ref name=Isakov>{{cite book|url= https://books.google.com/books?id=QahG1Ou1cyEC&pg=PA67|page= 67|title= Cutting Data for Turning of Steel|{{isbn|978-0-8311-3314-6}}|last1= Isakov|first1= Edmund|date= 2008-10-31}}</ref><ref name=Dshtein>{{cite journal|doi= 10.1007/BF00708374|title= Effect of selenium on the structure and properties of structural steel|date= 1979|last1= Gol'Dshtein|first1=Ya. E.|last2= Mushtakova|first2=T. L.|last3= Komissarova|first3=T. A.|journal= Metal Science and Heat Treatment|volume= 21|issue= 10|pages= 741–746|bibcode= 1979MSHT...21..741G|s2cid= 135853965}}</ref> Selenium produces the same machinability improvement in copper alloys.<ref name=Davis/>
{{clear}}

==Achávalites==
[[Image:Achavalite.jpg|thumb|right|250px|Black metallic crystals are the extremely rare iron selenide mineral achávalite from Cacheuta Mine, Mendoza, Argentina, associated with cacheutaite. Credit: [[c:user:David Hospital|David Hospital]].{{tlx|free media}}]]
Achávalite has the chemical formula {{chem|(Fe,Cu)|Se}}.

Achávalite (IMA symbol is Ahv<ref name=Warr/>) a selenide mineral that is a member of the nickeline group. It has only been found in a single Argentinian mine system, being first discovered in 1939 in a selenide deposit. The type locality is the Cacheuta mine, Sierra de Cacheuta, Mendoza, Argentina.<ref name=MindatAchavalite>[http://www.mindat.org/min-14.html Mindat Profile]</ref><ref name=WebminAchavalite>[http://webmineral.com/data/Achavalite.shtml Achavalite data on WebMineral]</ref><ref name=Hålenius>Hålenius, U., Hatert, F., Pasero, M., and Mills, S.J., IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 28. Mineralogical Magazine 79(7), 1859–1864</ref>
{{clear}}

==Clausthalites==
[[Image:Clausthalite-207330.jpg|right|thumb|250px|Clausthalite is a rare lead selenide exhibiting scintillating, metallic microcrystals covering the carbonate matrix. Credit: [[c:user:Rob Lavinsky|Rob Lavinsky]].{{tlx|free media}}]]
Clausthalite is a lead selenide mineral, with chemical formula PbSe. It is a face-centered mineral with Z = 4 formula units per unit cell.
{{clear}}

==Siderophiles==
[[Image:Elemental abundances.svg|right|thumb|350px|Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number. The rarest elements in the crust (shown in yellow) are not the heaviest, but are rather the siderophile (iron-loving) elements in the Goldschmidt classification of elements. These have been depleted by being relocated deeper into the Earth's core. Their abundance in meteoroid materials is relatively higher. Additionally, tellurium and selenium have been depleted from the crust due to formation of volatile hydrides. Credit: Gordon B. Haxel, Sara Boore, and Susan Mayfield from USGS.{{tlx|free media}}]]
'''Def.''' "an element that forms alloys easily with iron and [may be] concentrated in the Earth's core"<ref name=SiderophileWikt>{{ cite web
|title=siderophile
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|date=19 June 2013
|url=https://en.wiktionary.org/wiki/siderophile
|accessdate=2015-02-19 }}</ref> is called a '''siderophile'''.

Siderophile (metal-loving) chemical elements include W, P, Co, Ni, Mo, Re, and Ir.<ref name=Newsom>{{ cite book
|author=Horton E. Newsom
|title=Constraints on the origin of the Moon from the abundance of molybdenum and other siderophile elements, In: ''Origin of the moon''
|publisher=Lunar and Planetary Institute
|location=Kona, HI USA
|date=13 October 1986
|editor=W. K. Hartmann
|editor2=R. J. Phillips
|editor3=G. J. Taylor
|pages=203-29
|url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1986ormo.conf..203N&link_type=ARTICLE&db_key=AST&high=
|arxiv=
|bibcode=
|doi=
|pmid=
|isbn=
|accessdate=2016-10-31 }}</ref> 

"The platinum group elements (PGE: Os, Ir, Ru, Rh, Pt, and Pd) and Re are highly siderophile elements (HSE)".<ref name=Dale>{{ cite journal
|author=C.W. Dale, K.W. Burton, D.G. Pearson, A. Gannoun, O. Alard, T.W. Arglesb, and I.J. Parkinson
|title=The behaviour of highly siderophile elements in oceanic crust during subduction: whole-rock and mineral-scale insights from a high-pressure terrain
|journal=Geochimica et Cosmochimica Acta
|month=
|year=2009
|volume=73
|issue=5
|pages=1394-416
|url=http://dro.dur.ac.uk/10680/1/10680.pdf
|arxiv=
|bibcode=
|doi=10.1016/j.gca.2008.11.036
|pmid=
|accessdate=2016-10-31 }}</ref>

"We believe that silicon is a major element - about 5% [of the Earth's inner core] by weight could be silicon dissolved into the iron-nickel alloys."<ref name=Ohtani>{{ cite web
|author=Eiji Ohtani
|title=New candidate for 'missing element' in Earth's core
|publisher=BBC
|location=London, England
|date=10 January 2017
|url=http://www.bbc.com/news/science-environment-38561076
|accessdate=2017-01-11 }}</ref>

"The innermost part of Earth is thought to be a solid ball with a radius of about 1,200 km (745 miles)."<ref name=Morelle>{{ cite web
|author=Rebecca Morelle
|title=New candidate for 'missing element' in Earth's core
|publisher=BBC
|location=London, England
|date=10 January 2017
|url=http://www.bbc.com/news/science-environment-38561076
|accessdate=2017-01-11 }}</ref>

"It is mainly composed of iron, which makes up an estimated 85% of its weight, and nickel, which accounts for about 10% of the core."<ref name=Morelle/>

"These difficult experiments are really exciting because they can provide a window into what Earth's interior was like soon after it first formed, 4.5 billion years ago, when the core first started to separate from the rocky parts of Earth."<ref name=Redfern>{{ cite web
|author=Simon Redfern
|title=New candidate for 'missing element' in Earth's core
|publisher=BBC
|location=London, England
|date=10 January 2017
|url=http://www.bbc.com/news/science-environment-38561076
|accessdate=2017-01-11 }}</ref>

"But other workers have recently suggested that oxygen might also be important in the core."<ref name=Redfern/>

"In a way, these two options [oxygen was sucked into the core that would leave the rocky mantle surrounding the core depleted of the element or a larger amount of silicon had been incorporated in Earth's core more than four billion years ago, that would have left the rest of the planet relatively oxygen rich] are real alternatives that depend a lot on the conditions prevailing when Earth's core first began to form."<ref name=Redfern/>
{{clear}}

==Silicons==
[[Image:SiliconCroda.jpg|right|thumb|300px|Close up photo is of a piece of purified silicon. Credit: [[w:user:Enricoros|Enricoros]].{{tlx|free media}}]]
[[Image:Silicon spectrum visible.png|center|thumb|400px|Silicon spectrum is from 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Silicon (Si II) has two absorption bands at 412.805±10.8 nm and 413.088±13.0 nm with excitation potentials of 9.79 eV and 9.80 eV, respectively.<ref name=Sadakane/>

Silicon has an absorption line (Si IV) at 408.9 nm.<ref name=Conti>{{ cite journal
|author=Peter S. Conti
|author2=Eva M. Leep
|title=Spectroscopic observations of O-type stars. V. The hydrogen lines and lambda 4686 He II
|journal=The Astrophysical Journal
|month=October
|year=1974
|volume=193
|issue=10
|pages=113-24
|url=
|arxiv=
|bibcode=1974ApJ...193..113C
|doi=10.1086/153135
|pmid=
|accessdate=2013-03-23 }}</ref>

Elemental silicon is added to molten cast iron as ferrosilicon or silicocalcium alloys to improve performance in casting thin sections and to prevent the formation of cementite where exposed to outside air. The presence of elemental silicon in molten iron acts as a sink for oxygen, so that the steel carbon content, which must be kept within narrow limits for each type of steel, can be more closely controlled. Ferrosilicon production and use is a monitor of the steel industry, and although this form of elemental silicon is grossly impure, it accounts for 80% of the world's use of free silicon. Silicon is an important constituent of electrical steel, modifying its resistivity and ferromagnetic properties.

The properties of silicon may be used to modify alloys with metals other than iron. "Metallurgical grade" silicon is silicon of 95–99% purity. About 55% of the world consumption of metallurgical purity silicon goes for production of aluminium-silicon alloys (silumin alloys) for aluminium part casts, mainly for use in the automotive industry. Silicon's importance in aluminium casting is that a significantly high amount (12%) of silicon in aluminium forms a eutectic mixture which solidifies with very little thermal contraction. This greatly reduces tearing and cracks formed from stress as casting alloys cool to solidity. Silicon also significantly improves the hardness and thus wear-resistance of aluminium.<ref name=Apelian>{{cite web|last=Apelian |first=D.|date=2009
|title=Aluminum Cast Alloys: Enabling Tools for Improved Performance |publisher=North American Die Casting Association |location=Wheeling, Illinois
|url=https://web.archive.org/web/20120106013105/http://www.diecasting.org/research/wwr/WWR_AluminumCastAlloys.pdf|archive-date=2012-01-06}}</ref><ref name=Corathers>Corathers, Lisa A. [http://minerals.usgs.gov/minerals/pubs/commodity/silicon/myb1-2009-simet.pdf 2009 Minerals Yearbook]. USGS</ref>

"The relatively long-lived radionuclide of silicon, <sup>32</sup>Si, finds important applications as a tracer for studying aqueous geochemistry, biogeochemical cycles of silicon in the oceans, and the chronology of glaciers and biogenic silica-rich sediments in lacustrine and marine environments."<ref name=Lal>{{ cite journal
|author=D. Lal
|author2=B.L.K. Somayajulu
|title=Some aspects of the geochemistry of silicon isotopes
|journal=Tectonophysics
|month=June
|year=1984
|volume=105
|issue=1-4
|pages=383-97
|url=http://www.sciencedirect.com/science/article/pii/0040195184902154
|arxiv=
|bibcode=
|doi=10.1016/0040-1951(84)90215-4
|pmid=
|accessdate=2014-09-30 }}</ref>
{{clear}}

==Silicon hydrogenated amorphous carbons==

"The broad, 60 < FWHM < 100 nm, featureless luminescence band known as extended red emission (ERE) is seen in such diverse dusty astrophysical environments as reflection nebulae<sup>17</sup>, planetary nebulae<sup>3</sup>, HII regions (Orion)<sup>12</sup>, a Nova<sup>11</sup>, Galactic cirrus<sup>14</sup>, a dark nebula<sup>7</sup>, Galaxies<sup>8,6</sup> and the diffuse interstellar medium (ISM)<sup>4</sup>. The band is confined between 540-950 nm, but the wavelength of peak emission varies from environment to environment, even within a given object. ... the wavelength of peak emission is longer and the efficiency of the luminescence is lower, the harder and denser the illuminating radiation field is<sup>13</sup>. These general characteristics of ERE constrain the photoluminescence (PL) band and efficiency for laboratory analysis of dust analog materials."<ref name=Smith99>{{ cite journal
|author=T. L. Smith
|author2=A. N. Witt
|title=The Photoluminescence Efficiency of Extended Red Emission as a Constraint for Interstellar Dust
|journal=Bulletin of the American Astronomical Society
|month=December
|year=1999
|volume=31
|issue=
|pages=1479
|url=http://adsabs.harvard.edu/abs/1999AAS...195.7406S
|arxiv=
|bibcode=1999AAS...195.7406S
|doi=
|pmid=
|accessdate=2013-08-02 }}</ref>

"The PL efficiencies measured for [hydrogenated amorphous carbon] HAC and Si-HAC alloys are consistent with dust estimates for reflection nebulae and planetary nebulae, but exhibit substantial photoluminescence below 540 nm which is not observed in astrophysical environments."<ref name=Smith99/>
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==Moissanite==
[[Image:Moissanite-USGS-20-1001d-14x-.jpg|thumb|right|250px|Moissanite is native SiC. Credit: Andrew Silver.{{tlx|free media}}]]
Moissanite is native SiC.<ref name=Roberts/>
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==Silvers==
[[Image:Silver-280342.jpg|thumb|right|250px|These specimens are some of the most easily recognizable, dramatic and highly sought after silver specimens from the Western Hemisphere. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
[[Image:Native silver.jpg|thumb|left|250px|Native silver is on calcite from Kongsberg, Norway. Credit: Aram Dulyan.{{tlx|fairuse}}]]
[[Image:Silver crystal.jpg|thumb|center|250px|A pure (>99.95%) silver crystal, synthetic electrolytic is made with visible dendritic structures. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Silver spectrum visible.png|thumb|center|400px|Silver spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Native silver does occur as cubic, octahedral, or dodecahedral crystals; "also elongated, arborescent, reticulated, or as thin to thick wires."<ref name=Roberts/>

The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold, copper, zinc, cadmium, indium, tin, mercury, cobalt, nickel, palladium, manganese, phosphorus, and lead, and in minerals such as argentite and chlorargyrite.

Ag<sup>+</sup> is the stable species in aqueous solution and solids.<ref name=Greenwood/>
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==Bromyrites==
[[Image:Bromyrite.jpg|thumb|right|250px|This is a butterscotch colored bromargyrite cube from Broken Hill, New South Wales, Australia. Credit: Lou Perloff / Photo Atlas of Minerals.{{tlx|fairuse}}]]
Bromyrite, or bromargyrite, is a cubic silver bromide mineral (AgBr) that is 50 at % bromine.

The image on the right shows a butterscotch colored bromargyrite cube from Broken Hill, New South Wales, Australia.
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==Iodyrites==
[[Image:Iodyrite.jpg|thumb|right|250px|These are twinned iodyrite, or iodargyrite, crystals. Credit: Hudson Institute of Mineralogy.{{tlx|fairuse}}]]
Iodyrite (AgI) may be the most common mineral with large amounts of iodine found on Earth. It is 50 at % iodine.

On the right are twinned iodyrite, or iodargyrite, crystals are within a rock sample from Schöne Aussicht Mine, Dernbach, Neuwied, Wied Iron Spar District, Westerwald, Rhineland-Palatinate, Germany.
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==Sodiums==
[[Image:Sodium spectrum visible.png|center|thumb|400px|Sodium spectrum is ringrising 400 nm - 700 nm Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Bi-Na phase diagram.gif|thumb|left|250px|This is a phase diagram for the sodium-bismuth system. Credit: J. Sangster and A.D. Pelton.{{tlx|fairuse}}]]
[[Image:Na (Sodium).jpg|right|thumb|300px|Sodium metal is from the Dennis s.k collection. Credit: Dennis s.k.{{tlx|free media}}]]
[[Image:Flametest--Na.swn.jpg|thumb|center|100px|The image shows the color of sodium in a natural gas burner. Credit: [[c:user:Søren Wedel Nielsen|Søren Wedel Nielsen]].{{tlx|free media}}]].
The phase diagram on the left shows bcc (α-Na) at higher temperatures up to melting and hcp (β-Na) with decreasing temperature below the transition at 97.8°C.

Native sodium does not appear to occur on the surface of the Earth.

"Glaciers in the Karakoram and western Himalaya (site 2 and 3) show high annual snow accumulation rates and high annual fluxes of calcium, sodium, chloride, sulfate, and nitrate."<ref name=Wake>{{ cite journal
|author=Cameron P. Wake
|author2=Paul Andrew Mayewski
|author3=Xie Zichu
|author4=Wang Ping
|author5=Li Zhongquin
|title=Regional Distribution of Monsoon and Desert Dust Signals Recorded in Asian Glaciers
|journal=Geophysical Research Letters
|month=July 23
|year=1993
|volume=20
|issue=14
|pages=1411-4
|url=http://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1190&context=ers_facpub&sei-redir=1&referer=http%3A%2F%2Fscholar.google.com%2Fscholar%3Fq%3Dsodium%2Bglaciers%2B-acetic%2B-apples%26btnG%3D%26hl%3Den%26as_sdt%3D0%252C3#search=%22sodium%20glaciers%20-acetic%20-apples%22
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=2014-09-29 }}</ref>
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==Fluorites==
[[Image:Fluorine.jpg|thumb|right|250px|These are cyan colored fluorite crystals from Rogerley Mine, Frosterley, Weardale, North Pennines, Co. Durham, England, UK. Credit: [[c:User:Parent Géry|Parent Géry]].{{tlx|free media}}]]
[[Image:Fluorite-Quartz-cflo47a.jpg|thumb|left|250px|The fluorite crystal is just over 1 cm and is rimmed on one side with sparkling pyrite. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
Fluorite is a mineral composed of NaF.

Although fluorite usually appears violet or purple in color, the crystals at left are cyan with some blue or violet fluorite mixed in suggesting slight variations in composition.
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==Strontiums==
[[Image:Magnesium-Strontium phase diagram.png|thumb|right|250px|This is a magnesium-strontium phase diagram. Credit: A.A. Nayeb-Hashemi and J.B. Clark.{{tlx|fairuse}}]]
[[Image:FlammenfärbungSr.png|thumb|left|100px|The image shows the color of strontium in a natural gas burner. Credit: [[:de:user:Herge|Herge]].{{tlx|free media}}]]
[[Image:Plamenná zkouška kationt Sr+2.jpg|thumb|center|200px|The image shows the color of strontium in a natural gas burner. Credit: [[c:user:Roman Kynčl|Roman Kynčl]].{{tlx|free media}}]]
[[Image:Strontium destilled crystals.jpg|thumb|right|250px|The chemical element strontium as synthetic crystals, sealed under argon in a glass ampoule, purity (99.95 %). Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Strontium spectrum visible.png|thumb|center|400px|Strontium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Strontium at room temperature crystallizes in a fcc structure (α-Sr).

According to the phase diagram on the left, α-Sr transforms to γ-Sr (bcc) at 547°C.

Native strontium does not appear to occur on the surface of the Earth.

Three allotropes of metallic strontium exist, with transition points at 235 and 540&nbsp;°C.<ref name=Ropp>{{cite book | url = https://books.google.com/books?id=yZ786vEild0C&pg=PA16| page = 16 | title = Encyclopedia of the Alkaline Earth Compounds | isbn = 978-0-444-59553-9 | last1 = Ropp | first1 = Richard C. | date = 31 December 2012}}</ref><!--https://books.google.com/books?id=qJJrYnpT2pYC&pg=PA117&lpg=PA117-->

Strontium (Sr II) has two absorption bands: 407.771±11.3 nm and 421.552±10.4 nm.<ref name=Sadakane/>
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==Sulfurs==
{{main|Chemicals/Sulfurs}}

==Tantalums==
[[Image:Native tantalum from Greenland.jpg|thumb|right|250px|This is a piece of native tantalum from Kvanefjeld Mountain, Kuannersuit Plateau, Ilímaussaq complex, Narsaq, Kujalleq, Greenland. Credit: V.V. Seredin.{{tlx|fairuse}}]]
[[Image:Iron-Tantalum phase diagram.png|thumb|left|250px|This is a National Bureau of Standards phase diagram for Fe-Ta. Credit: L.J. Swartzendruber and E. Paul.{{tlx|fairuse}}]]
The iron-tantalum phase diagram on the left shows the bcc (α-Ta) phase from lower temperatures through and up to melting.

On the right is a scanning electron micrograph of a piece of native tantalum from Kvanefjeld Mountain, Kuannersuit Plateau, Ilímaussaq complex, Narsaq, Kujalleq, Greenland.
[[Image:Tantalum single crystal and 1cm3 cube.jpg|thumb|center|250px|A high purity (99.999 %) [[w:Tantalum|tantalum]] [[w:Single crystal|single crystal]], made by the [[w:Zone melting|floating zone process]], some single crystalline fragments of tantalum, as well as a high purity (99.99 % = 4N) 1 cm<sup>3</sup> tantalum cube for comparison. Credit: [[c:user:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Tantalum spectrum visible.png|thumb|center|400px|Tantalum spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Tantalum forms compounds in oxidation states −III to +V.

A tantalum-tellurium alloy forms quasicrystals.<ref name=Holleman2007>{{cite book|title=Lehrbuch der Anorganischen Chemie|date=2007|publisher=de Gruyter|{{isbn|978-3-11-017770-1}}|edition=102nd|language=de|author=Holleman, A. F.|author2=Wiberg, E.|author3=Wiberg, N.}}</ref>
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==Technetiums==
[[Image:Technetium-sample-cropped.jpg|thumb|right|250px|Technetium sample inside a sealed glass ampoule, filled with argon gas. 6x1 mm goldfoil covered with 99Tc powder (electroplated). Credit: Marco Cardin.{{tlx|free media}}]]
[[Image:Technetium spectrum visible.png|thumb|center|400px|Technetium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
:<math>\nu + ^{97}Mo \rightarrow e^- + ^{97}Tc,</math> and

:<math>\nu + ^{98}Mo \rightarrow e^- + ^{98}Tc.</math>

These "reactions probe precisely the time scale and neutrino-flux component of most interest: the boron-8 neutrino luminosity, which is the most sensitive monitor of variations in the solar core temperature, during and before the Pleistocene epoch. (The half-lives of technetium-97 and -98 are, respectively, 2.6 and 4.2 million years; the reaction on molybdenum-98 is induced only by the high-energy boron-8 neutrinos; and the reaction on molybdenum-97 may sample in addition the flux of beryllium-7 neutrinos, which are second only to boron-8 neutrinos in sensitivity to the core temperature.)"<ref name=Cowan>{{cite journal
 |last1=Cowan    |first1=Clyde L., Jr.
 |last2=Reines   |first2=Frederick
 |last3=Harrison |first3=Francis B. "Kiko"
 |last4=Kruse    |first4=Herald W.
 |last5=McGuire  |first5=Austin D.
 |year=1956
 |title=Detection of the free neutrino: A confirmation
 |journal=Science
 |volume=124  |issue=3212  |pages=103–104
 |bibcode=1956Sci...124..103C
 |doi=10.1126/science.124.3212.103  |pmid=17796274 }}</ref>
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==Telluriums==
[[Image:Tellurium-tmu07a.jpg|thumb|right|100px|This is a native tellurium crystal from the Emperor Mine, Vatukoula, Tavua Gold Field, Viti Levu, Fiji. Credit: [[c:User:Robert Stravinsky|Robert Stravinsky]].
{{tlx|free media}}]]
[[Image:Native tellurium.JPG|thumb|left|250px|On the upper left of the rock is native tellurium. Credit: Theodore W. Gray.{{tlx|fairuse}}]]
On the right is an example of native tellurium from the Emperor Mine, Vatukoula, Tavua Gold Field, Viti Levu, Fiji.

On the left is an encrustation of native tellurium on the upper left portion of a rock.
[[Image:Tellurium2.jpg|thumb|center|250px|Metallic tellurium is diameter 3.5 cm. Credit: Unknown author.{{tlx|free media}}]]
Tellurium is used in iron, stainless steel, copper, lead alloys, n-type bismuth telluride alloys<ref name=Nozariasbmar>{{Cite journal |last=Nozariasbmarz |first=Amin |last2=Poudel |first2=Bed |last3=Li |first3=Wenjie |last4=Kang |first4=Han Byul |last5=Zhu |first5=Hangtian |last6=Priya |first6=Shashank |date=2020-07-24 |title=Bismuth Telluride Thermoelectrics with 8% Module Efficiency for Waste Heat Recovery Application |url=https://www.sciencedirect.com/science/article/pii/S2589004220305277 |journal=iScience |language=en |volume=23 |issue=7 |pages=101340 |doi=10.1016/j.isci.2020.101340 |issn=2589-0042}}</ref>.
[[Image:Tellurium-89043.jpg|thumb|right|250px|Native tellurium crystal on sylvanite (Vatukoula, Viti Levu, Fiji), picture width 2 mm. Credit: [[c:user:Christian Rewitzer|Christian Rewitzer]].{{tlx|free media}}]]
[[Image:Tellurium spectrum visible.png|thumb|center|400px|Tellurium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Tellurium has two allotropes, crystalline and amorphous. When crystalline, tellurium is silvery-white with a metallic luster. The crystals are trigonal and chiral (space group 152 or 154 depending on the chirality), like the gray form of selenium. It is a brittle and easily pulverized metalloid. Amorphous tellurium is a black-brown powder prepared by precipitating it from a solution of tellurous acid or telluric acid (Te(OH)<sub>6</sub>).<ref name=Leddicotte>{{Cite journal|title = The radiochemistry of tellurium|issue = 3038|series = Nuclear science series|publisher = Subcommittee on Radiochemistry, National Academy of Sciences-National Research Council|first = G. W.|last = Leddicotte|date = 1961|page = 5|url = http://library.lanl.gov/cgi-bin/getfile?rc000049.pdf }}</ref>
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==Altaites==
[[Image:Altaite-170094.jpg|right|thumb|250px|Rich silvery veins and flecks are altaite throughout the matrix. Credit: [[c:user:Rob Lavinsky|Rob Lavinsky]].{{tlx|free media}}]]
Altaite has the chemical formula of PbTe. It has face-centered cubic structure with four formula molecules (Z=4) per unit cell. It is 50 atomic percent lead and 50 at. % tellurium. Crystal habits include cubic and octahedral crystals; but much more commonly found in massive and granular forms.
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==Tennessines==
[[Image:DecayChain Tennessine.svg|thumb|upright=1.5|right|250px|Decay chain of the atoms produced in the original experiment to produce tennessine. Credit: See authors.{{tlx|free media}}]]
The figures near the arrows describe experimental (black) and theoretical (blue) values for the lifetime and energy of each decay. Lifetimes may be converted to half-lives by multiplying by ln&nbsp;2.<ref name=Oganessian>{{cite journal|last1=Oganessian |first1=Yu.Ts. |author-link1=Yuri Oganessian |last2=Abdullin |first2=F.Sh. |last3=Bailey |first3=P.D. |last4=Benker |first4=D.E. |last5=Bennett |first5=M.E. |last6=Dmitriev |first6=S.N. |last7=Ezold |first7=J.G. |last8=Hamilton |first8=J.H. |last9=Henderson |first9=R.A. |first10=M.G. |last10=Itkis |first11=Yuri V. |last11=Lobanov |first12=A.N. |last12=Mezentsev |first13=K. J. |last13=Moody |first14=S.L. |last14=Nelson |first15=A.N. |last15=Polyakov | first16=C.E. |last16=Porter |first17=A.V. |last17=Ramayya |first18=F.D. |last18=Riley |first19=J.B. |last19=Roberto |first20=M. A. |last20=Ryabinin | first21=K.P. |last21=Rykaczewski |first22=R.N. |last22=Sagaidak | first23=D.A. |last23=Shaughnessy |first24=I.V. |last24=Shirokovsky |first25=M.A. |last25=Stoyer |first26=V.G. |last26=Subbotin | first27=R. |last27=Sudowe |first28=A.M. |last28=Sukhov |first29=Yu.S. |last29=Tsyganov |first30=Vladimir K. |last30=Utyonkov |first31=A.A. |last31=Voinov |first32=G.K. |last32=Vostokin | first33=P.A. |last33=Wilk |title=Synthesis of a new element with atomic number {{nowrap|{{mvar|Z}} {{=}} 117}} |year=2010 |journal=Physical Review Letters |volume=104 |issue=14 |page=142502 |doi=10.1103/PhysRevLett.104.142502 |pmid=20481935 |bibcode=2010PhRvL.104n2502O |s2cid=3263480 |url=https://semanticscholar.org/paper/ec9412add23e66f34b6bf51ebd7332278af413fc }}</ref>
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==Terbiums==
[[Image:Terbium spectrum visible.png|thumb|center|400px|Terbium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Pure terbium, 3 grams. Original size - 1 cm.jpg|thumb|right|250px|Terbium is a relatively resistant, sparsely toxic lanthanoid. Credit: Hi-Res Images of Chemical Elements.{{tlx|free media}}]]
Terbium is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite, xenotime and euxenite.

Terfenol-D, an alloy of the formula {{chem|Tb|x|Dy|1-x|Fe|2}} (x ≈ 0.3), is a magnetostrictive material.

Terbium is contained along with other rare earth elements in many minerals, including monazite ({{chem|(Ce,La,Th,Nd,Y)PO|4}} with up to 0.03% terbium), xenotime ({{chem|YPO|4}}) and euxenite ({{chem|(Y,Ca,Er,La,Ce,U,Th)(Nb,Ta,Ti)|2|O|6}} with 1% or more terbium). The crust abundance of terbium is estimated as 1.2&nbsp;mg/kg.<ref name=Patnaik>{{cite book | last =Patnaik | first =Pradyot | date = 2003 | title =Handbook of Inorganic Chemical Compounds | publisher = McGraw-Hill | pages = 920–921| {{isbn|978-0-07-049439-8}} | url= https://books.google.com/books?id=Xqj-TTzkvTEC&pg=PA243 | accessdate = 2009-06-06}}</ref> No terbium-dominant mineral has yet been found.<ref>{{ cite web |url=https://www.mindat.org/ |title=Mindat.org |author=Hudson Institute of Mineralogy |date=1993–2018 |website=www.mindat.org |accessdate=14 January 2018}}</ref>
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==Thalliums==
[[Image:Thallium flame.png|thumb|left|250px|The image shows the color of thallium in a natural gas burner. Credit: Ernest Z.
{{tlx|fairuse}}]]
[[Image:Thallium pieces in ampoule.jpg|thumb|right|250px|Pieces of very pure thallium are in a glass ampoule under argon. Credit: W. Oelen.{{tlx|free media}}]]
Thallium (I) ions are found geologically mostly in potassium-based ores. The radioisotope thallium-201 is the soluble chloride TlCl.

A mercury–thallium alloy, which forms a eutectic at 8.5% thallium, is reported to freeze at −60 °C, some 20 °C below the freezing point of mercury.

[[Image:Thallium spectrum visible.png|thumb|center|400px|Thallium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]

There is a green thallium line that shows up in arc spectra using "two to eight amperes at 120 volts, usually between ordinary arc carbons."<ref name=Nutting/>
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==Thoriums==
{{main|Chemicals/Thoriums}}
[[Image:Thorium sample 0.1g.jpg|right|thumb|300px|Thorium sample (99.9 % = 3N) is a thin sheet under argon in a glass ampoule, ca. 0.1 g. Credit: [[c:user:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
Thorium is a silvery, radioactive, metallic element. At room temperature and pressure, thorium crystallizes into a face-centered cubic lattice, where one thorium atom occupies each location of a black sphere in the diagram on the left.

Thorium can form alloys with many other metals. Addition of small proportions of thorium improves the mechanical strength of magnesium, and thorium-aluminium alloys have been considered as a way to store thorium in thorium nuclear reactors. Thorium forms eutectic mixtures with chromium and uranium, and it is completely miscible in both solid and liquid states with its lighter congener cerium.<ref name=Wickleder>{{cite book |doi=10.1007/1-4020-3598-5_3 |chapter=Thorium |title=The Chemistry of the Actinide and Transactinide Elements |year=2006 |last1=Wickleder |first1=Mathias S. |last2=Fourest |first2=Blandine |last3=Dorhout |first3=Peter K. |pages=52–160 |isbn=978-1-4020-3555-5 }}</ref>

[[Image:Cubic-face-centered.svg|thumb|left|100px|This diagram shows a face-centered cubic lattice. Credit: [[w:User:Daniel Mayer|Daniel Mayer]] and [[w:User:DrBob|DrBob]].{{tlx|free media}}]]
[[Image:Thorium spectrum visible.png|thumb|center|400px|Thorium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
'''Def.''' a chemical element (''symbol Th'') with atomic number 90 is called '''thorium'''.

Tetravalent thorium compounds are usually colourless or yellow, like those of silver or lead, as the Th<sup>4+</sup> ion has no 5f or 6d electrons.<ref name=Tretyakov>{{cite book|editor-first=Yu. D. |editor-last=Tretyakov|title= Non-organic chemistry in three volumes| publisher= Academy|date= 2007|volume= 3|series= Chemistry of transition elements|{{isbn|978-5-7695-2533-9}} }}</ref>
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==Monazites==
[[Image:Monazite - Rostadheia, Iveland, Norvegia 01.jpg|thumb|right|250px|This monazite is a tabular crystal from Rostadheia, Iveland, Norway. Credit: [[c:User:Aangelo|Aangelo]].{{tlx|free media}}]]
[[Image:MonaziteUSGOV.jpg|thumb|left|250px|The primary source of the world's thorium is the rare-earth-and-thorium-phosphate mineral monazite. Credit: USGS.{{tlx|free media}}]]
[[Image:Monazite-(Ce)-164025.jpg|thumb|right|200px|Monazite gets its name from the Greek word "monazein", which means "to be alone", in allusion to its isolated crystals and their rarity when first found. Credit: [[c:user:Robert M. Lavinsky|Robert M. Lavinsky]].{{tlx|free media}}]]
Monazite, a primarily reddish-brown phosphate mineral that contains rare-earth elements, with variability composition, is considered a group of minerals:<ref name=MindatMonazite>[http://www.mindat.org/min-2750.html Monazite group on Mindat.org]</ref>
* monazite-(Ce), (Ce,La,Nd,Th){{chem|PO|4}} (the most common member),
* monazite-(La), (La,Ce,Nd){{chem|PO|4}},
* monazite-(Nd), (Nd,La,Ce){{chem|PO|4}},
* monazite-(Sm), (Sm,Gd,Ce,Th){{chem|PO|4}},
* monazite-(Pr), (Pr,Ce,Nd,Th){{chem|PO|4}}.
(Ce,La,Nd,Th){{chem|PO|4}} occurs usually in small isolated crystals has a hardness of 5.0 to 5.5 on the Mohs scale of mineral hardness and is relatively dense, about 4.6 to 5.7 g/cm<sup>3</sup>.

The primary source of the world's thorium is the rare-earth, and thorium, phosphate mineral monazite.

Silica ({{chem|SiO|2}}) is present in trace amounts, as is small amounts of uranium.

Due to the alpha decay of thorium and uranium, monazite contains a significant amount of [[helium]], which can be extracted by heating.<ref name=Helium>[https://books.google.com/books?id=S-QDAAAAMBAJ&pg=PA460#v=onepage&f=true "Helium From Sand"], March 1931, ''Popular Mechanics'' p. 460.</ref>
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==Umbozerites==
[[Image:Umbozerite.jpg|thumb|right|200px|Umbozerite is from Karnasurt Mt., Lovozero Massif, Kola, Russia, size 4.2 cm. Credit: [[c:user:Weirdmeister|Weirdmeister]].{{tlx|free media}}]]
The IMA-CNMNC approved mineral symbol is Ubz.<ref name=Warr>Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43</ref>

Umbozerites have the chemical formula {{chem|Na|3|Sr|4|Th|[{{chem|Si(O,OH|(3-4)}}]|8}}, IMA formula {{chem|Na|3|Sr|4|ThSi|8|(O,OH)|24}}, common impurities: Ti,Ce,Fe,U,Mn,Ca,Ba,K, and Crystal System: Amorphous.<ref name=MindatUmbozerite>{{ cite web
|url=https://www.mindat.org/min-4092.html
|title=Umbozerite
|accessdate=19 November 2021 }}</ref>

Environment: In ussingite veinlets cutting alkalic rocks, type locality: Umbozero (Lake Umba), Kola Peninsula, Russia, dark brown prismatic umbozerite masses in pegmatite rock, Metamict - Mineral originally crystalline, now amorphous due to radiation damage, Pseudo Tetragonal - Crystals show a tetragonal shape, Umbozerite is Radioactive as defined in 49 CFR 173.403, greater than 70 Bq / gram.<ref name=WebmineralUmbozerite>{{ cite web
|url=http://www.webmineral.com/data/Umbozerite.shtml#.YZf8BS1h0RY
|title=Umbozerite Mineral Data
|accessdate=19 November 2021 }}</ref>

Occurrence: In pneumatolytic-hydrothermal veins cutting alkalic rocks in the upper part of a differentiated alkalic massif, Crystal Data: Metamict; tetragonal after recrystallization<ref name=HandbookUmbozerite>{{ cite web
|url=http://www.handbookofmineralogy.com/pdfs/umbozerite.pdf
|title=Umbozerite
|accessdate=19 November 2021 }}</ref>

Association: Ussingite, sphalerite, belovite, manganoan pectolite, lorenzenite, niobium-bearing minerals of the lomonosovite group.<ref name=HandbookUmbozerite/>

Distribution: Found on Mts. Karnasurt and Punkaruaiv, near Lake Umba, Lovozero massif, Kola Peninsula, Russia.<ref name=HandbookUmbozerite/>
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==Thuliums==
[[Image:Thulium sublimed dendritic and 1cm3 cube.jpg|thumb|right|250px|Thulium, sublimed-dendritic, high purity 99.99 % Tm/TREM. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Thulium spectrum visible.png|thumb|center|400px|Thulium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Thulium dissolves readily in dilute sulfuric acid to form solutions containing the pale green Tm (III) ions, which exist as {{chem|[Tm({{chem|OH|2}})|9|]|3+}} complexes:<ref>{{cite web |url= https://www.webelements.com/thulium/chemistry.html |title= Chemical reactions of Thulium |publisher=Webelements |access-date=2009-06-06}}</ref>

:{{chem|2Tm|(s)| + 3H|2|SO|4(aq)| → 2Tm|3+|(aq)| + 3SO|4 (aq)|2-| + 3H|2(aq)}}

{{clear}}

==Tins==
[[Image:Tin-160365.jpg|thumb|right|200px|This small piece of native tin is from the Badiko District, Bauchi State, Nigeria. Credit: [[c:User:Robert Lavinsky|Robert Lavinsky]].{{tlx|free media}}]]
[[Image:Native tin.jpg|thumb|left|200px|This is native tin from a porphyry copper deposit in the Bingham Deposit, Utah, USA. Credit: Alison Roberts.{{tlx|fairuse}}]]
Native tin such as in the images on the right and left occurs in two crystal forms: α-Sn (cubic) and β-Sn (tetragonal).<ref name=Roberts/>
[[Image:Sn-Alpha-Beta.jpg|thumb|center|250px|Purest tin 99,999 % = 5N, beta (left, white) and alpha (right, gray) allotropes. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Tin spectrum visible.png|thumb|center|400px|Tin spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
α-tin, the nonmetallic form or gray tin, is stable below {{convert|13.2|C|F}} and is brittle. α-tin has a diamond cubic crystal structure, similar to diamond, silicon or germanium. α-tin has no metallic properties, because its atoms form a covalent structure in which electrons cannot move freely. α-tin is a dull-gray powdery material with no common uses other than specialized semiconductor applications.<ref name=Holleman1985>{{cite book |publisher=Walter de&nbsp;Gruyter |date=1985 |edition=91–100 |pages=793–800 |{{isbn|978-3-11-007511-3}} |title=Lehrbuch der Anorganischen Chemie |first1=Arnold F. |last1=Holleman |last2=Wiberg |first2=Egon |last3=Wiberg |first3=Nils |chapter=Tin |language=de}}</ref>

The α-β transformation temperature is {{convert|13.2|C|F}}, but impurities (e.g. Al, Zn, etc.) lower it well below {{convert|0|C|F}}. With the addition of antimony or bismuth the transformation might not occur at all, increasing durability.<ref name=Schwartz>{{cite book |first=Mel |last=Schwartz |title=Encyclopedia of Materials, Parts and Finishes |edition=2nd |chapter=Tin and alloys, properties |publisher=CRC Press |year=2002 |{{isbn|978-1-56676-661-6}} }}</ref>

β–α transition of tin is at −40&nbsp;°C.

β-tin, the metallic form or white tin, has Tetragonal crystal system, body-centered tetragonal (BCT structure) and is stable at and above room temperature and is malleable.

γ-tin and σ-tin exist at temperatures above {{convert|161|C|F}}&nbsp; and pressures above several GPa.<ref name=Molodets>{{cite journal |first1=A.M. |last1=Molodets |last2=Nabatov |first2=S.S. |title=Thermodynamic potentials, diagram of state, and phase transitions of tin on shock compression |journal=High Temperature |volume=38 |issue=5 |year=2000 |pages=715–721 |doi=10.1007/BF02755923|s2cid=120417927 }}</ref>
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==Bronzes==

Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (such as aluminum, manganese, nickel or zinc) and sometimes non-metals, such as phosphorus, or metalloids such as arsenic, or silicon.

==Titaniums==
[[Image:Iron-titanium phase diagram.png|thumb|left|250px|This is an iron-titanium phase diagram. Credit: Hirokai.{{tlx|fairuse}}]]
[[Image:Titanium spectrum visible.png|thumb|center|400px|This is an emission spectrum that covers the visible range: 400 nm - 700 nm. Credit: [[c:User:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Ti,22.jpg|right|thumb|150px|Titanium strips inside a glass jar are part of the Everest Element Set from Russia. Credit: [[w:user:RTC|RTC]].{{tlx|free media}}]]
[[Image:Titan-crystal bar.JPG|thumb|center|250px|A titanium crystal bar, high purity 99.995 %, made by the iodide process at URALREDMET in the Soviet era. Credit: [[:de:user:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
"Microbeam analysis of eclogites from the ultrahigh-pressure metamorphic belt in Dabieshan, China has revealed native titanium inclusions in garnets of coesite eclogite. The inclusions are about 10 μm in size, have a submetallic luster from the thin oxidation film on the surface, and are brown under reflected light."<ref name=Chen>{{ cite journal
|author=Jing Chen, Jiliang Li, and Jun Wu
|title=Native titanium inclusions in the coesite eclogites from Dabieshan, China
|journal=Earth and Planetary Science Letters
|month=30 April
|year=2000
|volume=177
|issue=3-4
|pages=237-40
|url=http://www.sciencedirect.com/science/article/pii/S0012821X00000571
|arxiv=
|bibcode=
|doi=10.1016/S0012-821X(00)00057-1
|pmid=
|accessdate=2015-08-19 }}</ref>

Titanium is a dimorphic allotrope that "undergoes a phase transformation (hcp to bcc) at 882 °C [5]."<ref name=Panigrahi>{{ cite journal
|author=B.B. Panigrahi, M.M. Godkhindi , K. Das, P.G. Mukunda, and P. Ramakrishnan
|title=Sintering kinetics of micrometric titanium powder
|journal=Materials Science and Engineering: A
|month=15 April
|year=2005
|volume=396
|issue=1-2
|pages=255-62
|url=http://www.sciencedirect.com/science/article/pii/S0921509305000778
|arxiv=
|bibcode=
|doi=10.1016/j.msea.2005.01.016
|pmid=
|accessdate=2015-08-19 }}</ref>

As the phase diagram on the left indicates, there is a miscibility gap between bcc iron (α-Fe) and hcp (α-Ti) up to about 800°C.

Titanium (Ti) has green emission lines at 521.97, 522.268, 522.413, 524.729, and 526.596 nm as observed in solar limb faculae.<ref name=Stellmacher>{{ cite journal
|author=G. Stellmacher
|author2=E. Wiehr
|title=Geometric line elevation in solar limb faculae
|journal=Astronomy and Astrophysics
|month=August
|year=1991
|volume=248
|issue=1
|pages=227-31
|url=
|arxiv=
|bibcode=1991A&A...248..227S
|doi=
|pmid=
|accessdate=2012-02-18 }}</ref>

Titanium (Ti II) has an absorption band, 391.346-441.108 nm, with an excitation potential range of 0.60-3.08 eV.<ref name=Sadakane/> 

Titanium has two emission lines at 456.3757 and 457.1971 nm from Ti II.<ref name=Catanzaro>{{ cite journal
|author=G. Catanzaro
|title=First spectroscopic analysis of β Scorpii C and β Scorpii E Discovery of a new HgMn star in the multiple system β Scorpii
|journal=Astronomy & Astrophysics
|month=January
|year=2010
|volume=509
|issue=
|pages=7
|url=http://www.aanda.org/articles/aa/pdf/2010/01/aa13332-09.pdf
|arxiv=
|bibcode=
|doi=10.1051/0004-6361/200913332
|pmid=
|accessdate=2013-01-18 }}</ref>

Titanium can be alloyed with iron, aluminium, zirconium, nickel, vanadium, copper, and molybdenum.
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==Osbornites==

''Osbornite'' is a very rare natural form of titanium nitride (TiN), found almost exclusively in meteorites.<ref>{{cite web |website=Mindat.org |url=http://www.mindat.org/min-3035.html |title=Osbornite |publisher=Hudson Institute of Mineralogy |accessdate=February 29, 2016}}</ref><ref name=WebmineralOsbornites>{{cite web|url=http://webmineral.com/data/Osbornite.shtml#.V_cFauArJaQ|website=Mineralogy Database|title=Osbornite Mineral Data|date=September 5, 2012|accessdate=October 6, 2015|publisher=David Barthelmy}}</ref>
{{clear}}

==Tungstens==
[[Image:Native tungsten Luna 24 landing site.jpg|thumb|right|250px|The small, bright crystalline mass on the right of this electron micrograph is native tungsten. Credit: Andrei V. Mokhov.{{tlx|fairuse}}]]
[[Image:Fe-W-phase-diagram.jpg|thumb|left|250px|This is an iron-tungsten phase diagram. Credit: Satyendra.{{tlx|fairuse}}]]
[[Image:Wolfram evaporated crystals and 1cm3 cube.jpg|thumb|center|250px|Tungsten rods are shown with evaporated crystals, partially oxidized with colorful tarnish. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Tungsten spectrum visible.png|thumb|center|400px|Tungsten spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
In the scanning electron micrograph on the right is a bright grain, or crystalline mass, of native tungsten. The sample is a fragment of lunar silicate glass from the Luna 24 landing site, Mare Crisium, The Moon. The fragment is bright in backscattered electrons.

The iron-tungsten phase diagram on the left shows that the bcc phase of tungsten (α-W) occurs from lower temperatures on up to the melting temperature.

Tungsten is usually alloyed with nickel, iron, or cobalt to form heavy alloys,

Tungsten carbide (chemical formula: WC) is a chemical compound (specifically, a carbide) containing equal parts of tungsten and carbon atoms.
{{clear}}

==Uraniums==
[[Image:Uranium spectrum visible.png|thumb|center|400px|Uranium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:HEUraniumC.jpg|thumb|right|250px|A billet of highly enriched uranium was recovered from scrap processed at the Y-12 National Security Complex Plant. Credit: [[c:user:Choihei|Choihei]].{{tlx|free media}}]]
Uranium "not only exists in the forms of tetravalent and hexavalent uranium oxides, but also occurs in the form of native uranium [from the hydrothermal Guidong and Zhuguang uranium deposits of the middle Nanling metallogenic belt, Southern China]."<ref name=Ziying>{{ cite journal
|author=Li Ziying, Huang Zhizhang, Li Xiuzhen, Guo Jian, Fan Chou
|title=The Discovery of Natural Native Uranium and Its Significance
|journal=Acta Geologica Sinica
|date=24 October 2015
|volume=89
|issue=5
|pages=1561-1567
|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/1755-6724.12564
|arxiv=
|bibcode=
|doi=10.1111/1755-6724.12564
|pmid=
|accessdate=29 June 2022 }}</ref>

Depleted uranium (DU) is alloyed with 1–2% other elements, such as titanium or molybdenum.<ref>{{cite web|url=http://www.gulflink.osd.mil/du_ii/du_ii_tabe.htm#TAB_E_Development_of_DU_Munitions|title=Development of DU Munitions|year=2000|work=Depleted Uranium in the Gulf (II)|publisher=Gulflink, official website of Force Health Protection & Readiness}}</ref> UCo is a superconductor at 1.70°K.<ref name=Chandrasekhar>{{ cite journal
|author=B. S. Chandrasekhar and J. K. Hulm
|title=The electrical resistivity and super-conductivity of some uranium alloys and compounds
|journal=Journal of Physics and Chemistry of Solids
|date=November 1958
|volume=7
|issue=2-3
|pages=259-267
|url=https://www.sciencedirect.com/science/article/abs/pii/0022369758902713
|arxiv=
|bibcode=
|doi=10.1016/0022-3697(58)90271-3
|pmid=
|accessdate=29 June 2022 }}</ref>

UMnGe (Pnma, a = 686.12(9), b = 425.49(6) and c = 736.5(1) pm) adopts the orthorhombic structure of TiNiSi and {{chem|U|2|Mn|3|Ge}} (P6<sub>3</sub>/mmc, a = 524.3(2) and c = 799.2(3) pm) possesses the hexagonal {{chem|Mg|2|Cu|3|Si}}-type structure (ordered variant of the hexagonal Laves phase {{chem|MgZn|2}}).<ref name=Hoffmann>{{ cite journal
|author=Rolf-Dieter Hoffmann, Rainer Pöttgen, Bernard Chevalier, Etienne Gaudin, and Samir F. Matar
|title=The ternary germanides UMnGe and {{chem|U|2|Mn|3|Ge}}
|journal=Solid State Sciences
|date=July 2013
|volume=21
|issue=
|pages=73-80
|url=https://www.sciencedirect.com/science/article/abs/pii/S1293255813001301
|arxiv=
|bibcode=
|doi=10.1016/j.solidstatesciences.2013.04.006
|pmid=
|accessdate=29 June 2022 }}</ref>
{{clear}}

==Vanadiums==
[[Image:Native vanadium crystals.png|thumb|right|250px|In this backscattered electron micrograph on the left, the native vanadium crystals have been colorized in red. Credit: MikhailI Ostrooumov and Yuri Taran.{{tlx|fairuse}}]]
[[Image:Fe-V Phase Diagram.gif|thumb|left|200px|This Fe-V phase diagram shows which phases are to be expected at equilibrium for different combinations of vanadium content and temperature. Credit: Computational Thermodynamics Inc.{{tlx|fairuse}}]]
[[Image:Vanadium2.jpg|right|thumb|300px|Vanadium pieces are shown. Credit: W. Oelen.{{tlx|free media}}]]
[[Image:Vanadiumoxidationstates.jpg|thumb|left|upright|100px|Oxidation states of vanadium are shown from left +2 (lilac), +3 (green), +4 (blue) and +5 (yellow). Credit: Steffen Kristensen.
{{tlx|free media}}]]
"[N]ative vanadium [occurs] in natural fumarolic incrustations and in the mineral assemblage precipitated in silica tubes inserted into high-temperature (750-830°C) fumaroles of Colima volcano – the most active volcano of Mexico, and one of the most active in the Americas. [...] The new mineral and its name (“vanadium”) have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (Williams et al., 2013; IMA # 2012- 021a). The holotype material has been deposited in the Geological Museum of National Mexican University (New mineral collection of Mexican Mineralogical Society with cataloged under FIM 12/01)."<ref name=Ostrooumov>{{ cite journal
|author=MikhailI Ostrooumov and Yuri Taran
|title=Discovery of Native Vanadium, a New Mineral from the Colima Volcano, State of Colima (Mexico)
|journal=Revista de la Sociedad Española de Mineralogía
|month=20 May
|year=2015
|volume=
|issue=
|pages=109-10
|url=http://www.uhu.es/fexp/sem2015/arc/macla/macla_20_109-110.pdf
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=2015-08-19 }}</ref>

In the image on the right, the backscattered electron micrograph on the left side, has the native vanadium crystals colorized in red. The energy dispersive X-ray spectroscopy (EDS) spectrum on the right shows the vanadium peaks plus small amounts of Fe and S.<ref name=Ostrooumov/>

As the phase diagram on the left indicates vanadium is bcc down to lower temperatures from its melting point.

[[Image:Vanadium spectrum visible.png|thumb|center|400px|This is an emission spectrum that covers the visible range: 400 nm - 700 nm. Credit: [[c:User:McZusatz|McZusatz]].{{tlx|free media}}]]

The chemistry of vanadium is noteworthy for the accessibility of the four adjacent [[w:oxidation state|oxidation state]]s 2-5. In [[w:Metal ions in aqueous solution|aqueous solution]] the colours are lilac V<sup>2+</sup>(aq), green V<sup>3+</sup>(aq), blue VO<sup>2+</sup>(aq) and, at high pH, yellow VO<sub>4</sub><sup>2-</sup>.

Vanadium (V II) has an absorption band, 392.973-403.678 nm, with an excitation potential range of 1.07-1.81 eV.<ref name=Sadakane/>
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==Xenons==
{{main|Chemicals/Xenons}}

==Ytterbiums==
[[Image:Ytterbium-3.jpg|thumb|right|250px|Ytterbium metal solid is 0.5 x 1 cm. Credit: [[c:user:Jurii|Jurii]].{{tlx|free media}}]]
[[Image:Euxenite - Vegusdal, Norvegia 01.jpg|thumb|left|250px|Euxenite  crystal aggregation (11 cm) is from Vegusdal, Norway. Credit: [[c:user:Aangelo|Aangelo]].{{tlx|free media}}]]
Natural ytterbium is a mixture of seven stable isotopes, which altogether are present at concentrations of 0.3 parts per million.

Ytterbium has three allotropes: alpha, beta and gamma; their transformation temperatures are −13&nbsp;°C and 795&nbsp;°C,<ref name=Hammond/> although the exact transformation temperature depends on the pressure and stress.<ref name=Bucher/> The beta allotrope (6.966&nbsp;g/cm<sup>3</sup>) exists at room temperature, and it has a face-centered cubic crystal structure. The high-temperature gamma allotrope (6.57&nbsp;g/cm<sup>3</sup>) has a body-centered cubic crystalline structure.<ref name=Hammond/> The alpha allotrope (6.903&nbsp;g/cm<sup>3</sup>) has a hexagonal crystalline structure and is stable at low temperatures.<ref name=Holleman/> The beta allotrope has a metallic electrical conductivity at normal atmospheric pressure, but it becomes a semiconductor when exposed to a pressure of about 16,000 atmospheres (1.6&nbsp;GPa). Its electrical resistivity increases ten times upon compression to 39,000 atmospheres (3.9&nbsp;GPa), but then drops to about 10% of its room-temperature resistivity at about 40,000&nbsp;atm (4.0&nbsp;GPa).<ref name=Hammond/><ref name=Emsley2003/>

[[Image:Ytterbium spectrum visible.png|thumb|center|400px|Ytterbium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]

The alpha allotrope is diamagnetic.<ref name=Bucher>{{Cite journal | last1 = Bucher | first1 = E. | last2 = Schmidt | first2 = P. | last3 = Jayaraman | first3 = A. | last4 = Andres | first4 = K. | last5 = Maita | first5 = J. | last6 = Nassau | first6 = K. | last7 = Dernier | first7 = P. | doi = 10.1103/PhysRevB.2.3911 | title = New First-Order Phase Transition in High-Purity Ytterbium Metal | journal = Physical Review B | volume = 2 | issue = 10 | pages = 3911 | year = 1970 |bibcode = 1970PhRvB...2.3911B }}</ref>

Ytterbium is paramagnetic at temperatures above 1.0 K.<ref name=Jackson>Jackson, M. (2000). [http://www.irm.umn.edu/quarterly/irmq10-3.pdf "Magnetism of Rare Earth"]. The IRM quarterly 10(3): 1</ref>

Natural ytterbium is composed of seven stable isotopes: <sup>168</sup>Yb, <sup>170</sup>Yb, <sup>171</sup>Yb, <sup>172</sup>Yb, <sup>173</sup>Yb, <sup>174</sup>Yb, and <sup>176</sup>Yb, with <sup>174</sup>Yb being the most common, at 31.8% of the natural abundance). 27 radioisotopes have been observed, with the most stable ones being <sup>169</sup>Yb with a half-life of 32.0 days, <sup>175</sup>Yb with a half-life of 4.18 days, and <sup>166</sup>Yb with a half-life of 56.7 hours. All of the remaining radioactive isotopes have half-lives that are less than two hours, and most of these have half-lives under 20 minutes. Ytterbium also has 12 meta states, with the most stable being <sup>169m</sup>Yb (''t''<sub>1/2</sub> 46 seconds).<ref name="nucleonica">{{cite web |url=http://www.nucleonica.net/unc.aspx |title=Nucleonica: Universal Nuclide Chart |date=2007–2011 |publisher=Nucleonica |accessdate=July 22, 2011}}</ref><ref name=Audi>Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001</ref>

The isotopes of ytterbium range in atomic weight from 147.9674 atomic mass unit (u) for <sup>148</sup>Yb to 180.9562&nbsp;u for <sup>181</sup>Yb. The primary decay mode of ytterbium isotopes lighter than the most abundant stable isotope, <sup>174</sup>Yb, is electron capture, and the primary decay mode for those heavier than <sup>174</sup>Yb is beta decay. The primary decay products of ytterbium isotopes lighter than <sup>174</sup>Yb are thulium isotopes, and the primary decay products of ytterbium isotopes with heavier than <sup>174</sup>Yb are lutetium isotopes.<ref name="nucleonica" /><ref name=Audi/>

It occurs in the minerals monazite, euxenite, and xenotime.
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==Ytterbium Oxides==

The +2 oxidation state occurs only in solid compounds and reacts in some ways similarly to the alkaline earth metal compounds; for example, ytterbium(II) oxide (YbO) shows the same structure as calcium oxide (CaO).<ref name=Holleman/>
{{clear}}

==Yttriums==
[[Image:Yttrium sublimed dendritic and 1cm3 cube.jpg|thumb|right|250px|Yttrium, sublimed-dendritic, high purity 99.99 % Y/TREM, as well as an argon arc remelted 1 cm<sup>3</sup> yttrium cube for comparison, purity 99.9 %. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Yttrium spectrum visible.png|thumb|center|400px|Yttrium spectrum is 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:Xenotímio1.jpeg|thumb|left|250px|Xenotime crystals contain yttrium. Credit: Tom Epaminondas (mineral collector) / Eurico Zimbres (FGEL-UERJ).{{tlx|free media}}]]
Yttrium (Y II) has an absorption band from 395.035 to 439.802 nm, with an excitation potential range of 0.10-0.13 eV.<ref name=Sadakane/>

The orange system, in [[orange astronomy]] is a number of emission lines very close together forming a band in the orange portion of the visible spectrum. These lines are usually associated with particular molecular species, including ScO, YO, and TiO.<ref name=Herbig>{{ cite journal
|author=G. H. Herbig
|title=VY Canis Majoris. IV. The emission bands of ScO
|journal=The Astrophysical Journal
|month=March
|year=1974
|volume=188
|issue=3
|pages=533-8
|url=
|arxiv=
|bibcode=1974ApJ...188..533H
|doi=10.1086/152744
|pmid=
|accessdate=2012-02-01 }}</ref>

Small amounts of yttrium (0.1 to 0.2%) have been used to reduce the grain sizes of chromium, molybdenum, titanium, and zirconium.<ref>{{cite book|chapter=Yttrium|title =Periodic Table of Elements: LANL |url = http://periodic.lanl.gov/39.shtml|publisher = Los Alamos National Security}}</ref> Yttrium is used to increase the strength of aluminium and magnesium alloys.<ref name=Lide2008>{{Cite book|editor = Lide, David R.|chapter = Yttrium
|date = 2007–2008|title = CRC Handbook of Chemistry and Physics|volume = 4
|page = 41|location = New York|publisher = CRC Press|{{isbn = 978-0-8493-0488-0}} }}</ref> The addition of yttrium to alloys generally improves workability, adds resistance to high-temperature recrystallization, and significantly enhances resistance to high-temperature oxidation.<ref name=Daane>Daane, A. H. (1968). "Yttrium". In Hampel, Clifford A. (ed.). The Encyclopedia of the Chemical Elements. New York: Reinhold Book Corporation. pp. 810–821. LCCN 68029938. OCLC 449569.</ref>
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==Yttrium nitrides==

Yttrium nitride (YN) is formed when the metal is heated to 1000&nbsp;°C in nitrogen.<ref name=Daane>Daane, A. H. (1968). "Yttrium". In Hampel, Clifford A. (ed.). The Encyclopedia of the Chemical Elements. New York: Reinhold Book Corporation. pp. 810–821. LCCN 68029938. OCLC 449569.</ref>

==Zincs==
[[Image:Zinc spectrum visible.png|center|thumb|400px|Zinc emission spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
[[Image:ZincMetalUSGOV.jpg|right|thumb|300px|Pure zinc metal wedge is shown. Credit: United States Geological Survey.{{tlx|free media}}]]
[[Image:Zinc burning.JPG|thumb|left|200px|The image shows the color of zinc in a natural gas burner. Credit: [[c:user:Chemicalinterest|Chemicalinterest]].{{tlx|free media}}]]
[[Image:Zinc fragment sublimed and 1cm3 cube.jpg|thumb|left|250px|Zinc, purity 99.995 %, left: a crystaline fragment of an ingot, right: sublimed-dendritic, and a 1 cm<sup>3</sup> zinc cube for comparison. Credit: [[c:User:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
"Satellite images taken over the past several decades show the dramatic disappearance of ice, including on the island’s inland areas, where the ice fields can in places be up to three and a half kilometers deep."<ref name=Weiden>{{ cite book
|author=Silvia von der Weiden
|title=As Greenland's Glaciers Recede, A Rush On The Riches Buried Below
|publisher=WorldCrunch
|location=
|date=21 March 2012
|url=http://www.worldcrunch.com/business-finance/as-greenland-s-glaciers-recede-a-rush-on-the-riches-buried-below/c2s4915/
|accessdate=20 September 2014 }}</ref>

"Along with uranium, zinc, iron ore, copper and gold, Greenland’s ancient rocks also harbor large quantities of those minerals known as “rare earth,” among them lanthanum, cerium, neodymium, praesodymium, terbium and yttrium."<ref name=Weiden/>

Metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium.<ref name=Ingalls>{{Cite book|title=Production and Properties of Zinc: A Treatise on the Occurrence and Distribution of Zinc Ore, the Commercial and Technical Conditions Affecting the Production of the Spelter, Its Chemical and Physical Properties and Uses in the Arts, Together with a Historical and Statistical Review of the Industry|last=Ingalls|first=Walter Renton|publisher=The Engineering and Mining Journal|date=1902|pages=142–6|url=https://books.google.com/books?id=RhNDAAAAIAAJ&pg=PA133}}</ref>

Although neither zinc nor zirconium is ferromagnetic, their alloy {{chem|ZrZn|2}} exhibits ferromagnetism below 35&nbsp;K.<ref name=Lide2006>David R. Lide, ed. (2006). Handbook of Chemistry and Physics (87th ed.). Boca Raton, Florida: CRC Press, Taylor & Francis Group. {{ISBN|978-0-8493-0487-3}}.</ref>
{{clear}}

==Brasses==
[[Image:Diagramme binaire Cu Zn.svg|thumb|right|250px|Copper-zinc (Cu-Zn) binary phase diagram is for brass. Credit: [[c:user:Cdang|Cdang]].{{tlx|free media}}]]
The earliest brasses may have been natural alloys made by smelting zinc-rich copper ores.<ref name=Craddock>Craddock, P.T. and Eckstein, K (2003) "Production of Brass in Antiquity by Direct Reduction" in Craddock, P.T. and Lang, J. (eds) ''Mining and Metal Production Through the Ages'' London: British Museum pp. 226–7</ref>

The compositions of these early "brass" objects are highly variable and most have zinc contents of between 5% and 15% wt which is lower than in brass produced by cementation.<ref name=Craddock/>

Alpha-brass is {{chem|Cu|3|Zn}}.<ref name=MindatBrasses>https://www.mindat.org/min-6830.html</ref>
{{clear}}

==Zincites==
[[Image:Zincite from Arizona.jpg|thumb|right|250px|This giant chunk of a crystal cluster is enormous. Credit: [https://www.flickr.com/people/cobalt/ cobalt123].{{tlx|free media}}]]
Zincite has the formula ZnO.<ref name=MindatZincites>http://www.mindat.org/min-4410.html</ref>
# Colour: Red, orange, yellow, white; rarely green.<ref name=MindatZincites/>
# Lustre: Sub-Vitreous, Resinous, Waxy, Greasy, Silky, Dull, Earthy.<ref name=MindatZincites/>
# Crystal System: Hexagonal.<ref name=MindatZincites/>
{{clear}}

==Zinc selenides==

"ZnSe appears as an attractive material to blue and near UV optoelectronics."<ref name=Vigue>{{ cite journal
|author=F. Vigué
|author2=E. Tournié
|author3=J.-P. Faurie
|title=Zn(Mg)BeSe-based p-i-n photodiodes operating in the blue-violet and near-ultraviolet spectral range
|journal=Applied Physics Letters
|month=January
|year=2000
|volume=76
|issue=2
|pages=242-4
|url=http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4915124
|arxiv=
|bibcode=
|doi=10.1063/1.125715
|pmid=
|accessdate=2013-06-01 }}</ref>
{{clear}}

==Zirconiums==
[[Image:Zirconium crystal bar and 1cm3 cube.jpg|right|thumb|300px|Purest zirconium 99.97%, two samples of crystal bar showing different surface textures, made by crystal bar process, as well as a highly pure (99,95 % = 3N5) 1 cm<sup>3</sup> zirconium cube for comparison. Credit: [[c:use:Alchemist-hp|Alchemist-hp]].{{tlx|free media}}]]
[[Image:Fe-Zr phase diagram.gif|thumb|left|300px|This is a binary phase diagram of the iron-zirconum system. Credit: D. Arias and J.P. Abriata.{{tlx|fairuse}}]]
[[Image:Zirconium spectrum visible.png|center|thumb|400px|Zirconium spectrum is for 400 nm - 700 nm. Credit: [[c:user:McZusatz|McZusatz]].{{tlx|free media}}]]
Zirconium is a lustrous, greyish-white, soft, ductile, malleable metal that is solid at room temperature, though it is hard and brittle at lesser purities.<ref name=Emsley2001/><ref name="madehow">{{ cite web
|title= Zirconium, In: ''How Products Are Made''
|publisher= Advameg Inc.
|date= 2007
|url= http://www.madehow.com/Volume-1/Zirconium.html
|accessdate= 2008-03-26 }}</ref>

Zirconium is highly resistant to corrosion by alkalis, acids, salt water and other agents.<ref name=Lide2008/> However, it will dissolve in hydrochloric and sulfuric acid, especially when fluorine is present.<ref name="Nostrand">{{ cite book
|date=2005
|title=Zirconium, In: ''Van Nostrand's Encyclopedia of Chemistry''
|editor=Glenn D. Considine
|pages=1778–1779
|place=New York
|publisher=Wylie-Interscience
|isbn=978-0-471-61525-5
}}</ref>

Alloys with zinc are magnetic at less than 35&nbsp;K.<ref name=Lide2008/>

The melting point of zirconium is 1855&nbsp;°C (3371&nbsp;°F), and the boiling point is 4371&nbsp;°C (7900&nbsp;°F).<ref name=Lide2007>{{ cite book
|contribution=
|date=2007
|title=Zirconium, In: ''CRC Handbook of Chemistry and Physics''
|editor=David R. Lide
|volume=4
|page=42
|location=New York
|publisher=CRC Press
|{{isbn=978-0-8493-0488-0}} }}</ref> Zirconium has an electronegativity of 1.33 on the Pauling scale for the elements within the d-block with known electronegativities, zirconium has the fifth lowest electronegativity after hafnium, yttrium, lanthanum, and actinium.<ref>{{ cite web
|author=Mark Winter
|title=Electronegativity (Pauling)
|publisher=University of Sheffield
|date= 2007
|url= http://www.webelements.com/webelements/properties/text/image-flash/electroneg-pauling.html
|accessdate= 2008-03-05
}}</ref>

At room temperature zirconium exhibits a hexagonally close-packed crystal structure, α-Zr, which changes to β-Zr, a body-centered cubic crystal structure, at 863&nbsp;°C, β-phase until the melting point.<ref>{{ cite journal
|author=Schnell I
|author2=Albers RC
|title=Zirconium under pressure: phase transitions and thermodynamics
|journal=Journal of Physics: Condensed Matter
|volume=18
|pages=16
|date=January 2006
|doi=10.1088/0953-8984/18/5/001
|issue=5
|bibcode= 2006JPCM...18.1483S
}}</ref>

As the Fe-Zr phase diagram on the left demonstrates, zirconium has a hcp structure (α-Zr) at lower temperatures, including room temperature, and a bcc structure (β-Zr) at higher temperatures up to melting.

"Zirconium isotopic abundances [may be] determined from ZrO bandheads near 6925 Å via synthetic spectra for a sample of S stars."<ref name=Lambert>{{ cite journal
|author=David L. Lambert
|author2=Verne V. Smith
|author3=Maurizio Busso
|author4=Roberto Gallino
|author5=Oscar Straniero
|title=The Chemical Composition of Red Giants. IV. The Neutron Density at the s-Process Site
|journal=The Astrophysical Journal
|month=September 1,
|year=1995
|volume=450
|issue=09
|pages=302-17
|url=http://adsabs.harvard.edu/abs/1995ApJ...450..302L
|arxiv=
|bibcode=1995ApJ...450..302L
|doi=10.1086/176141
|pmid=
|accessdate=2013-08-01 }}</ref>

Zirconium (Zr II) has an absorption band, 395.824-415.624 nm, with an excitation potential of 0.52-0.75 eV.<ref name=Sadakane/>

The mineral zircon is the most important source of zirconium.

Naturally occurring zirconium is composed of five isotopes:
# <sup>90</sup>Zr is the most common, making up 51.45% of all zirconium,
# <sup>91</sup>Zr,
# <sup>92</sup>Zr and
# <sup>94</sup>Zr are stable, although <sup>94</sup>Zr is predicted to undergo double beta decay (not observed experimentally) with a half-life of more than 1.10×10<sup>17</sup>&nbsp;years,
# <sup>96</sup>Zr has a half-life of 2.4×10<sup>19</sup>&nbsp;years, is the longest-lived radioisotope of zirconium and is the least common, comprising only 2.80% of zirconium.<ref name="nubase">{{cite journal
|title=Nubase2003 Evaluation of Nuclear and Decay Properties
|journal=Nuclear Physics A
|volume=729
|issue=1
|pages=3–128
|date=2003
|doi=10.1016/j.nuclphysa.2003.11.001
|author=Audi, G
|bibcode=2003NuPhA.729....3A
|last2=Bersillon
|first2=O.
|last3=Blachot
|first3=J.
|last4=Wapstra
|first4=A. H.
|url=http://hal.in2p3.fr/in2p3-00014184
|citeseerx=10.1.1.692.8504
}}</ref>

Twenty-eight artificial isotopes of zirconium have been synthesized, ranging in atomic mass from 78 to 110.
# <sup>88</sup>Zr, decays by electron capture,
# <sup>93</sup>Zr is the longest-lived artificial isotope, with a half-life of 1.53×10<sup>6</sup>&nbsp;years,
# <sup>110</sup>Zr, the heaviest isotope of zirconium, is the most radioactive, with an estimated half-life of 30&nbsp;milliseconds.<ref name="nubase"/>

Radioactive isotopes at or above mass number 93 decay by electron emission, whereas those at or below 89 usually decay by positron emission.

Five isotopes of zirconium also exist as metastable isomers:
# <sup>83m</sup>Zr,
# <sup>85m</sup>Zr,
# <sup>89m</sup>Zr, is the longest lived with a half-life of 4.161&nbsp;minutes,
# <sup>90m1</sup>Zr,
# <sup>90m2</sup>Zr has the shortest half-life at 131&nbsp;nanoseconds, and
# <sup>91m</sup>Zr.<ref name="nubase"/>

<sup>88</sup>Zr: "When irradiated with low-energy neutrons from a nuclear reactor, each atom of zirconium-88 had a high probability of absorbing a neutron into its nucleus, causing the element to transform into another isotope, zirconium-89. The reaction was about 85,000 times as likely to occur as predicted."<ref name=Conover>{{ cite book
|author=Emily Conover
|title=A weird type of zirconium soaks up neutrons like a sponge
|publisher=Science News
|location=
|date=January 7, 2019
|url=https://www.sciencenews.org/article/weird-type-zirconium-soaks-neutrons-sponge?utm_source=email&utm_medium=email&utm_campaign=latest-newsletter-v2
|accessdate=9 January 2019 }}</ref>

"<sup>88</sup>Zr has a thermal neutron capture cross-section of 861,000 ± 69,000 barns (1σ uncertainty), which is five orders 
of magnitude larger than the theoretically predicted value of 10 barns<sup>2</sup>."<ref name=Shusterman>{{ cite journal
|author=Jennifer A. Shusterman
|author2=Nicholas D. Scielzo
|author3=Keenan J. Thomas
|author4=Eric B. Norman
|author5=Suzanne E. Lapi
|author6=C. Shaun Loveless
Nickie J. Peters, J. David Robertson, Dawn A. Shaughnessy & Anton P. Tonchev
|title=The surprisingly large neutron capture cross-section of <sup>88</sup>Zr
|journal=Nature
|date=7 January 2019
|volume=18
|issue=838
|pages=10
|url=https://www.nature.com/articles/s41586-018-0838-z.epdf?referrer_access_token=dHufYV4FNXVsGEZyZ6g46dRgN0jAjWel9jnR3ZoTv0Mc5ChkkjTroRA03db24PlRo5oLvqS_cQqr3Ff-LqPf8ZW9FUa-GytgPnedZFlJA3sJHCPQ-Wb0LQHgUooFhbXFT2u0gCjThP3WjpB7tVio9JlGs_SyStggLGcHQu7l_hT2N2TYQtXDBqInN55QTO7c3rRCffeqfGp9nOYIDqm3LtP2DriqXGv9cFWQjji220S1F_HyMnoVXS8PYQKna8D8JsxmnGI5DENoTSqjSgCoRCc8rj1Fc9iU2JqJ1KGsMmzESD_APHFsnyOGfnXNr1URBD6edhDX5R8Ax1g0rQo0mTNUjtaJyadTVh12QnoMqcg%3D&tracking_referrer=www.sciencenews.org
|arxiv=
|bibcode=
|doi=10.1038/s41586-018-0838-z
|pmid=
|accessdate=9 January 2019 }}</ref>

"Only one other isotope, xenon-135, is known to be better at capturing neutrons. Previously studied versions of zirconium are much more reluctant to take on another neutron, with absorption probabilities about a millionth that of zirconium-88, or less."<ref name=Conover/>

"Isotopes with a high neutron capture probability can be used to control nuclear reactors by sopping up loose neutrons, slowing the rate of reactions."<ref name=Conover/>
{{clear}}

==Hypotheses==
{{main|Hypotheses}}
# The use of satellites should provide ten times the information as sounding rockets or balloons.

A control group for a radiation satellite would contain
# a radiation astronomy telescope,
# a two-way communication system,
# a positional locator,
# an orientation propulsion system, and
# power supplies and energy sources for all components.

A control group for radiation astronomy satellites may include an ideal or rigorously stable orbit so that the satellite observes the radiation at or to a much higher resolution than an Earth-based ground-level observatory is capable of.

==See also==
{{div col|colwidth=20em}}
* [[Gamma-ray astronomy]]
* [[Rocks/Meteorites|Meteorites]]
* [[Radiation/Neutrons|Neutron astronomy]]
* [[Optical astronomy]]
* [[Minerals/Pnictogens|Pnictogens]]
* [[Submillimeter astronomy]]
* [[X-ray astronomy]]
{{Div col end}}

==References==
{{reflist|2}}

==External links==
* [https://en.wikipedia.org/wiki/Glossary_of_meteoritics Glossary of meteoritics]
* [http://www.iau.org/ International Astronomical Union]
* [http://nedwww.ipac.caltech.edu/ NASA/IPAC Extragalactic Database - NED]
* [http://nssdc.gsfc.nasa.gov/ NASA's National Space Science Data Center]
* [http://www.osti.gov/ Office of Scientific & Technical Information]
* [http://www.adsabs.harvard.edu/ The SAO/NASA Astrophysics Data System]
* [http://www.scirus.com/srsapp/advanced/index.jsp?q1= Scirus for scientific information only advanced search]
* [http://cas.sdss.org/astrodr6/en/tools/quicklook/quickobj.asp SDSS Quick Look tool: SkyServer]
* [http://simbad.u-strasbg.fr/simbad/ SIMBAD Astronomical Database]
* [http://nssdc.gsfc.nasa.gov/nmc/SpacecraftQuery.jsp Spacecraft Query at NASA]
* [http://heasarc.gsfc.nasa.gov/cgi-bin/Tools/convcoord/convcoord.pl Universal coordinate converter]

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