Editing Tungsten (section)

{{Short description| Chemical element, symbol W and atomic number 74}}
{{About|the chemical element}}
{{Good article}}
{{Pp-semi-indef|small=yes}}
{{Infobox tungsten}}

'''Tungsten''' (also called '''wolfram''')<ref>[https://www.merriam-webster.com/dictionary/wolfram "wolfram"] on Merriam-Webster.</ref><ref>[https://web.archive.org/web/20171208004126/https://en.oxforddictionaries.com/definition/wolfram "wolfram"] on Oxford Dictionaries.</ref> is a [[chemical element]]; it has [[Symbol (chemistry)|symbol]] '''W''' and [[atomic number]] 74. It is a metal found naturally on [[Earth]] almost exclusively in [[chemical compound|compounds]] with other elements. It was identified as a distinct element in 1781 and first isolated as a metal in 1783. Its important [[ore]]s include [[scheelite]] and [[wolframite]], the latter lending the element its alternative name.

The [[free element]] is remarkable for its robustness, especially the fact that it has the highest [[melting point]] of all known elements, melting at {{convert|3422|C|F K|0}}. It also has the highest [[boiling point]], at {{cvt|5930|C|F K|0}}.<ref>{{cite journal |doi=10.1021/je1011086 |title=Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks |url=https://www.researchgate.net/publication/231538496 |vauthors=Zhang Y, Evans JR, Zhang S |journal=J. Chem. Eng. Data |date=January 2011 |volume=56 |issue=2 |pages= 328–337}}</ref> Its density is 19.254&nbsp;g/cm<sup>3</sup>,<ref name="Arblaster 2018" /><!-- Citation defined in infobox: {{cite book |last=Arblaster |first= John W. |title=Selected Values of the Crystallographic Properties of Elements |publisher=ASM International |publication-place=Materials Park, Ohio |date=2018 |isbn=978-1-62708-155-9}}--> comparable with that of [[uranium]] and [[gold]], and much higher (about 1.7 times) than that of [[lead]].<ref name="daintith">{{cite book |last=Daintith |first=John |title=Facts on File Dictionary of Chemistry |edition=4th |location=New York |publisher=Checkmark Books |date=2005 |isbn=978-0-8160-5649-1 }}</ref> Polycrystalline tungsten is an intrinsically [[brittle]]<ref>{{cite book |title=Tungsten: properties, chemistry, technology of the element, alloys, and chemical compounds|first = Erik|last = Lassner|author2=Schubert, Wolf-Dieter | publisher = Springer|date = 1999|isbn = 978-0-306-45053-2|chapter-url = https://books.google.com/books?id=foLRISkt9gcC&pg=PA20|chapter = low temperature brittleness|pages = 20–21}}</ref><ref>{{cite journal |last1=Prakash |first1=C. |last2=Lee |first2=H. |last3=Alucozai |first3=M. |last4=Tomar |first4=V. |date=2016 |title=An analysis of the influence of grain boundary strength on microstructure dependent fracture in polycrystalline tungsten |journal=International Journal of Fracture |volume=199 |pages=1–20 | doi=10.1007/s10704-016-0083-0|s2cid=137928096 }}</ref><ref>{{cite journal |last1=Gludovatz |first1=B. |last2=Wurster |first2=S. |last3=Weingärtner |first3=T. |last4=Hoffmann |first4=A. |last5=Pippan |first5=R. |title=Influence of impurities on the fracture behavior of tungsten |journal=Philosophical Magazine |date=2011 |volume=91 |issue=22 |pages=3006–3020 |doi=10.1080/14786435.2011.558861 |bibcode=2011PMag...91.3006G|s2cid=137145004 |url=https://hal.archives-ouvertes.fr/hal-00688940 |type=Submitted manuscript }}</ref> and [[hardness|hard]] material (under standard conditions, when uncombined), making it difficult to [[metalworking|work into metal]]. However, pure single-crystalline tungsten is more [[ductility|ductile]] and can be cut with a hard-steel [[hacksaw]].<ref name="albert">{{cite book |last=Stwertka |first=Albert |title=A Guide to the elements |edition=2nd |location=New York |publisher=Oxford University Press |date=2002 |isbn=978-0-19-515026-1 }}</ref>

Tungsten occurs in many alloys, which have numerous applications, including incandescent [[light bulb]] filaments, [[X-ray tube]]s, electrodes in [[gas tungsten arc welding]], [[superalloy]]s, and [[radiation protection|radiation shielding]]. Tungsten's hardness and high [[density]] make it suitable for military applications in [[Kinetic energy penetrator|penetrating projectiles]]. Tungsten compounds are often used as industrial [[catalyst]]s. Its largest use is in [[tungsten carbide]], a wear-resistant metal used in [[metalworking]], [[mining]], and [[construction]].<ref>{{Cite web |year=2024 |title=Tungsten Statistics and Information |url=https://www.usgs.gov/centers/national-minerals-information-center/tungsten-statistics-and-information |access-date=2024-07-04 |website=National Minerals Information Center |publisher=U.S. Geological Survey |language=en}}</ref> About 50% of tungsten is used in tungsten carbide, with the remaining major use being alloys and steels: less than 10% is used in other compounds.<ref name=":1" />

Tungsten is the only metal in the third [[Transition metal|transition]] series that is known to occur in [[biomolecule]]s, being found in a few species of bacteria and [[archaea]].  However, tungsten interferes with [[molybdenum]] and [[copper]] metabolism and is somewhat toxic to most forms of animal life.<ref>{{cite journal
|title = The active sites of molybdenum- and tungsten-containing enzymes
|author = McMaster, J.
|author2 = Enemark, John H.
|name-list-style = amp
|journal = Current Opinion in Chemical Biology
|volume = 2
|issue = 2
|pages = 201–207
|date = 1998
|doi = 10.1016/S1367-5931(98)80061-6
|pmid = 9667924}}</ref><ref>{{cite journal
|title = Molybdenum and tungsten in biology
|author = Hille, Russ
|journal = Trends in Biochemical Sciences
|volume = 27
|issue = 7
|pages = 360–367
|date = 2002
|doi = 10.1016/S0968-0004(02)02107-2
|pmid = 12114025}}</ref>