View source for Xenon

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{{About|the chemical element}}
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{{Infobox xenon}}
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'''Xenon''' is a [[chemical element]]; it has [[symbol (chemistry)|symbol]] '''Xe''' and [[atomic number]] 54. It is a dense, colorless, odorless [[noble gas]] found in [[Earth's atmosphere]] in trace amounts.<ref>{{cite encyclopedia | title = Xenon | year = 2007 | url = http://www.infoplease.com/ce6/sci/A0852881.html | encyclopedia = Columbia Electronic Encyclopedia | edition = 6th | publisher = Columbia University Press | access-date = October 23, 2007 }}</ref> Although generally unreactive, it can undergo a few [[chemical reaction]]s such as the formation of [[xenon hexafluoroplatinate]], the first [[noble gas compound]] to be synthesized.<ref name="Husted_2003">{{cite web | vauthors = Husted R, Boorman M | title = Xenon | date = December 15, 2003 | url = http://periodic.lanl.gov/54.shtml | publisher = [[Los Alamos National Laboratory]], Chemical Division | access-date = September 26, 2007 }}</ref><ref>{{cite book | vauthors = Rabinovich VA, Vasserman AA, Nedostup VI, Veksler LS | title = Thermophysical properties of neon, argon, krypton, and xenon | journal = <!--None--> |location = Washington, DC | volume = 10 | date = 1988 | series = National Standard Reference Data Service of the USSR | publisher = Hemisphere Publishing Corp. | isbn = 978-0-89116-675-7 | bibcode = 1988wdch...10.....R }}</ref><ref name="Freemantle_2003" />

Xenon is used in [[Flashtube#Xenon|flash lamps]]<ref name="Burke_2003" /> and [[xenon arc lamp|arc lamps]],<ref name="Mellor_2000" /> and as a [[general anesthetic]].<ref name="Sanders_2005">{{cite journal | vauthors = Sanders RD, Ma D, Maze M | title = Xenon: elemental anaesthesia in clinical practice | journal = [[British Medical Bulletin]] | volume = 71 | issue = 1 | pages = 115–135 | year = 2005 | pmid = 15728132 | doi = 10.1093/bmb/ldh034 | doi-access = free }}</ref> The first [[excimer laser]] design used a xenon [[dimerization (chemistry)|dimer]] molecule (Xe<sub>2</sub>) as the [[active laser medium|lasing medium]],<ref name="Basov_1971" /> and the earliest [[laser]] designs used xenon flash lamps as [[laser pumping|pumps]].<ref name="Toyserkani_2004" /> Xenon is also used to search for hypothetical [[weakly interacting massive particles]]<ref name="Ball_2002">{{cite journal | vauthors = Ball P | title = Xenon outs WIMPs | journal = [[nature (journal) | nature]] | date = May 1, 2002 | doi = 10.1038/news020429-6 | url = http://www.nature.com/news/2002/020429/full/news020429-6.html | access-date = October 8, 2007 | url-access = subscription }}</ref> and as a [[propellant]] for [[ion thruster]]s in spacecraft.<ref name="Saccoccia_2006" />

Naturally occurring xenon consists of [[isotopes of xenon|seven stable isotopes]] and two long-lived radioactive isotopes. More than 40 unstable xenon isotopes undergo [[radioactive decay]], and the isotope ratios of xenon are an important tool for studying the early history of the [[Solar System]].<ref name="Kaneoka_1998" /> Radioactive [[xenon-135]] is produced by [[beta decay]] from [[iodine-135]] (a product of [[nuclear fission]]), and is the most significant (and unwanted) [[neutron absorber]] in [[nuclear reactor]]s.<ref name="Stacey_2007" />

== History ==
Xenon was discovered in England by the Scottish chemist [[William Ramsay]] and English chemist [[Morris Travers]] on July 12, 1898,<ref name="Nobel">{{cite web | vauthors = Ramsay SW | title = Nobel Lecture – The Rare Gases of the Atmosphere | date = July 12, 1898 | url = https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1904/ramsay-lecture.html | website = Nobel prize | publisher = Nobel Media AB | access-date = November 15, 2015 }}</ref> shortly after their discovery of the elements [[krypton]] and [[neon]]. They found xenon in the residue left over from evaporating components of [[liquid air]].<ref>{{cite journal | vauthors = Ramsay W, Travers MW | title = On the extraction from air of the companions of argon, and neon | journal = Report of the Meeting of the British Association for the Advancement of Science | pages = 828 | year = 1898 }}</ref><ref>{{cite web | vauthors = Gagnon S | title = It's Elemental – Xenon | url = http://education.jlab.org/itselemental/ele054.html | access-date = June 16, 2007 | publisher = Thomas Jefferson National Accelerator Facility | archive-date = June 12, 2020 | archive-url = https://web.archive.org/web/20200612100726/https://education.jlab.org/itselemental/ele054.html | url-status = dead }}</ref> Ramsay suggested the name ''xenon'' for this gas from the [[Greek language|Greek]] word ξένον ''xénon'', neuter singular form of ξένος ''xénos'', meaning 'foreign(er)', 'strange(r)', or 'guest'.<ref>{{cite book | title = The New International Encyclopædia | pages = 906 | date = 1904 | veditors = Gilman DC, Peck HT, Colby FM | publisher = [[Dodd, Mead and Company]] }}</ref><ref>{{cite book | title = The Merriam-Webster New Book of Word Histories | pages = 513 | date = 1991 | url = https://books.google.com/books?id=IrcZEZ1bOJsC&pg=PA513 | publisher = Merriam-Webster | isbn = 978-0-87779-603-9 }}</ref> In 1902, Ramsay estimated the proportion of xenon in the Earth's atmosphere to be one part in 20 million.<ref>{{cite journal | vauthors = Ramsay W | title = An Attempt to Estimate the Relative Amounts of Krypton and of Xenon in Atmospheric Air | journal = [[Proceedings of the Royal Society of London]] | volume = 71 | issue = 467–476 | pages = 421–426 | year = 1902 | doi = 10.1098/rspl.1902.0121 | s2cid = 97151557 | bibcode = 1902RSPS...71..421R }}</ref>

During the 1930s, American engineer [[Harold Eugene Edgerton|Harold Edgerton]] began exploring [[strobe light]] technology for [[High-speed photography|high speed photography]]. This led him to the invention of the xenon [[Flashtube|flash lamp]] in which light is generated by passing brief electric current through a tube filled with xenon gas. In 1934, Edgerton was able to generate flashes as brief as one [[microsecond]] with this method.<ref name="Burke_2003" /><ref>{{cite web | title = History | url = http://www.millisecond-cine.com/history.html | archive-url = https://web.archive.org/web/20060822141910/http://www.millisecond-cine.com/history.html | archive-date = August 22, 2006 | publisher = Millisecond Cinematography | access-date = November 7, 2007 }}</ref><ref>{{cite encyclopedia | vauthors = Paschotta R | title = Lamp-pumped lasers | date = November 1, 2007 | url = https://www.rp-photonics.com/lamp_pumped_lasers.html | encyclopedia = Encyclopedia of Laser Physics and Technology | publisher = RP Photonics | access-date = November 7, 2007 }}</ref>

In 1939, American physician [[Albert R. Behnke]] Jr. began exploring the causes of "drunkenness" in deep-sea divers. He tested the effects of varying the breathing mixtures on his subjects, and discovered that this caused the divers to perceive a change in depth. From his results, he deduced that xenon gas could serve as an [[Anesthesia|anesthetic]]. Although Russian toxicologist [[Nikolay Lazarev|Nikolay V. Lazarev]] apparently studied xenon anesthesia in 1941, the first published report confirming xenon anesthesia was in 1946 by American medical researcher John H. Lawrence, who experimented on mice. Xenon was first used as a surgical anesthetic in 1951 by American anesthesiologist Stuart C. Cullen, who successfully used it with two patients.<ref>{{cite journal | vauthors = Marx T, Schmidt M, Schirmer U, Reinelt H | title = Xenon anesthesia | journal = Journal of the Royal Society of Medicine | volume = 93 | issue = 10 | pages = 513–517 | date = Oct 2000 | pmid = 11064688 | pmc = 1298124 | doi = 10.1177/014107680009301005 | url = http://www.jrsm.org/cgi/reprint/93/10/513.pdf | access-date = October 2, 2007 }}</ref>
[[File:An acrylic cube specially prepared for element collectors containing an ampoule filled with liquefied xenon.JPG|thumb|left|An acrylic cube specially prepared for element collectors containing a glass [[ampoule]] of liquefied xenon]]
Xenon and the other noble gases were for a long time considered to be completely chemically inert and not able to form [[chemical compound|compounds]]. However, while teaching at the [[University of British Columbia]], [[Neil Bartlett (chemist)|Neil Bartlett]] discovered that the gas [[platinum hexafluoride]] (PtF<sub>6</sub>) was a powerful [[Redox|oxidizing]] agent that could oxidize oxygen gas (O<sub>2</sub>) to form [[dioxygenyl hexafluoroplatinate]] ({{chem|O|2|+|[PtF|6|]|-}}).<ref>{{cite journal | vauthors = Bartlett N, Lohmann DH | title = Dioxygenyl hexafluoroplatinate (V), {{chem | O | 2 | + | [PtF | 6 | ] | -}}|journal=Proceedings of the Chemical Society|location=London|issue=3|pages=115|date=1962|doi=10.1039/PS9620000097|publisher=Chemical Society}}</ref> Since O<sub>2</sub> (1165 kJ/mol) and xenon (1170&nbsp;kJ/mol) have almost the same first [[Ionization energy|ionization potential]], Bartlett realized that platinum hexafluoride might also be able to oxidize xenon. On March 23, 1962, he mixed the two gases and produced the first known compound of a noble gas, [[xenon hexafluoroplatinate]].<ref name="Bartlett_1962">{{cite journal | vauthors = Bartlett N | title = Xenon hexafluoroplatinate (V) Xe<sup>+</sup>[PtF<sub>6</sub>]<sup>−</sup> | journal = Proceedings of the Chemical Society | location = London | issue = 6 | pages = 218 | date = 1962 | doi = 10.1039/PS9620000197 | publisher = [[Chemical Society]] }}</ref><ref name="Freemantle_2003">{{cite magazine | vauthors = Freemantle M | title = Chemistry at its Most Beautiful | volume = 81 | issue = 34 | pages = 27–30 | date = August 25, 2003 | doi = 10.1021/cen-v081n034.p027 | magazine = Chemical & Engineering News }}</ref>

Bartlett thought its composition to be Xe<sup>+</sup>[PtF<sub>6</sub>]<sup>−</sup>, but later work revealed that it was probably a mixture of various xenon-containing salts.<ref name="Graham_2000">{{cite journal | vauthors = Graham L, Graudejus O, Narendra JK, Bartlett N | title = Concerning the nature of XePtF<sub>6</sub> | journal = Coordination Chemistry Reviews | volume = 197 | issue = 1 | pages = 321–334 | date = 2000 | doi = 10.1016/S0010-8545(99)00190-3 }}</ref><ref>{{cite book | vauthors = Holleman AF, Wiberg E | title = Inorganic Chemistry | location = San Diego | date = 2001 | veditors = Aylett | others = translated by Mary Eagleson and William Brewer | publisher = [[Academic Press]] | isbn = 978-0-12-352651-9 }}; translation of ''Lehrbuch der Anorganischen Chemie'', BJ founded by A. F. Holleman, [https://books.google.com/books?id=vEwj1WZKThEC&pg=PA395 continued by Egon Wiberg], edited by Nils Wiberg, Berlin: de Gruyter, 1995, 34th edition, {{ISBN|3-11-012641-9}}.</ref><ref>{{cite web | vauthors = Steel J | title = Biography of Neil Bartlett | date = 2007 | url = http://chemistry.berkeley.edu/publications/news/2006/bio_bartlett.php | publisher = College of Chemistry, University of California, Berkeley | access-date = October 25, 2007 | url-status = dead | archive-url = https://web.archive.org/web/20090923143345/http://chemistry.berkeley.edu/publications/news/2006/bio_bartlett.php | archive-date = September 23, 2009 }}</ref> Since then, many other xenon compounds have been discovered,<ref>{{cite journal | vauthors = Bartlett N | title = The Noble Gases | journal = Chemical & Engineering News | volume = 81 | issue = 36 | pages = 32–34 | date = September 9, 2003 | doi = 10.1021/cen-v081n036.p032 | url = http://pubs.acs.org/cen/80th/noblegases.html | publisher = American Chemical Society | access-date = October 1, 2007 | url-access = subscription }}</ref> in addition to some compounds of the noble gases [[argon]], [[krypton]], and [[radon]], including [[argon fluorohydride]] (HArF),<ref>{{cite journal | vauthors = Khriachtchev L, Pettersson M, Runeberg N, Lundell J, Räsänen M | title = A stable argon compound | journal = Nature | volume = 406 | issue = 6798 | pages = 874–876 | date = August 24, 2000 | pmid = 10972285 | doi = 10.1038/35022551 | s2cid = 4382128 | bibcode = 2000Natur.406..874K }}</ref> [[krypton difluoride]] (KrF<sub>2</sub>),<ref>{{cite book | vauthors = Lynch CT, Summitt R, Sliker A | title = CRC Handbook of Materials Science | year = 1980 | publisher = [[CRC Press]] | isbn = 978-0-87819-231-1 | url-access = registration | url = https://archive.org/details/crchandbookofmat0000unse }}</ref><ref>{{cite journal | vauthors = MacKenzie DR | title = Krypton Difluoride: Preparation and Handling | journal = Science | volume = 141 | issue = 3586 | pages = 1171 | date = Sep 1963 | pmid = 17751791 | doi = 10.1126/science.141.3586.1171 | s2cid = 44475654 | bibcode = 1963Sci...141.1171M }}</ref> and [[Radon difluoride|radon fluoride]].<ref>{{cite journal | vauthors = Fields PR, Stein L, Zirin MH | title = Radon Fluoride | journal = [[Journal of the American Chemical Society]] | volume = 84 | issue = 21 | pages = 4164–4165 | year = 1962 | doi = 10.1021/ja00880a048 | bibcode = 1962JAChS..84.4164F }}</ref> By 1971, more than 80 xenon compounds were known.<ref name="CRC">{{cite web | title = Xenon | url = http://www.chemnetbase.com/periodic_table/elements/xenon.htm | work = Periodic Table Online | publisher = CRC Press | access-date = October 8, 2007 | archive-url = https://web.archive.org/web/20070410040717/http://chemnetbase.com/periodic_table/elements/xenon.htm | archive-date = April 10, 2007 }}</ref><ref>{{cite journal | vauthors = Moody GJ | title = A Decade of Xenon Chemistry | journal = Journal of Chemical Education | volume = 51 | issue = 10 | pages = 628–630 | year = 1974 | doi = 10.1021/ed051p628 | url = http://www.eric.ed.gov/ERICWebPortal/recordDetail?accno=EJ111480 | access-date = October 16, 2007 | bibcode = 1974JChEd..51..628M | url-access = subscription }}</ref>

In November 1989, [[IBM]] scientists demonstrated a technology capable of manipulating individual [[atom]]s. The program, called [[IBM (atoms)|IBM in atoms]], used a [[scanning tunneling microscope]] to arrange 35 individual xenon atoms on a substrate of chilled crystal of [[nickel]] to spell out the three-letter company initialism. It was the first-time atoms had been precisely positioned on a flat surface.<ref>Browne, Malcolm W. (April 5, 1990) [https://www.nytimes.com/1990/04/05/us/2-researchers-spell-ibm-atom-by-atom.html "2 Researchers Spell 'I.B.M.,' Atom by Atom"]. ''The New York Times''</ref>

== Characteristics ==
[[File:Solid and liquid xenon.jpg|left|thumb|A layer of solid xenon building inside a high voltage apparatus. The layer of solid xenon (white color) is surrounded by liquid xenon (transparent).]]
[[File:Xe nanoparticles in Al.jpg|thumb|left|Liquid (featureless) and crystalline solid Xe nanoparticles produced by implanting Xe<sup>+</sup> ions into aluminium at room temperature]]
Xenon has [[atomic number]] 54; that is, its nucleus contains 54 [[proton]]s. At [[standard temperature and pressure]], pure xenon gas has a density of 5.894&nbsp;kg/m<sup>3</sup>, about 4.5 times the density of the Earth's atmosphere at sea level, 1.217&nbsp;kg/m<sup>3</sup>.<ref>{{cite web | vauthors = Williams DR | title = Earth Fact Sheet | date = April 19, 2007 | url = http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html | publisher = NASA | access-date = October 4, 2007 | archive-date = May 8, 2013 | archive-url = https://web.archive.org/web/20130508021904/http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html | url-status = dead }}</ref> As a liquid, xenon has a density of up to 3.100&nbsp;g/mL, with the density maximum occurring at the triple point.<ref name="Aprile_2006">{{cite book | vauthors = Aprile E, Bolotnikov AE, Doke T | title = Noble Gas Detectors | pages = 8–9 | date = 2006 | publisher = [[Wiley-VCH]] | isbn = 978-3-527-60963-5 | url = https://books.google.com/books?id=tsnHM8x6cHAC&pg=PT1 }}</ref> Liquid xenon has a high [[polarizability]] due to its large atomic volume, and thus is an excellent solvent. It can dissolve hydrocarbons, biological molecules, and even water.<ref>{{Cite journal | vauthors = Rentzepis PM, Douglass DC | title = Xenon as a solvent | journal = Nature | volume = 293 | issue = 5828 | pages = 165–166 | date = September 10, 1981 | doi = 10.1038/293165a0 | s2cid = 4237285 | bibcode = 1981Natur.293..165R }}</ref> Under the same conditions, the density of solid xenon, 3.640&nbsp;g/cm<sup>3</sup>,<ref name="Aprile_2006" /> is greater than the average density of [[granite]], 2.75&nbsp;g/cm<sup>3</sup>. Under [[pascal (unit)|gigapascals]] of [[pressure]], xenon forms a metallic phase.<ref>{{cite journal | vauthors = Caldwell WA, Nguyen J, Pfrommer B, Louie S, Jeanloz R | title = Structure, bonding and geochemistry of xenon at high pressures | journal = [[science (journal) | science]] | volume = 277 | issue = 5328 | pages = 930–933 | date = 1997 | doi = 10.1126/science.277.5328.930 }}</ref>

Solid xenon changes from [[Face-centered cubic]] (fcc) to [[Close-packing of spheres|hexagonal close packed]] (hcp) crystal phase under pressure and begins to turn metallic at about 140&nbsp;GPa, with no noticeable volume change in the hcp phase.<ref name="citeb37b7ff9">{{cite web | vauthors = Fontes E | title = Golden Anniversary for Founder of High-pressure Program at CHESS | publisher = Cornell University | url = https://news.chess.cornell.edu/articles/2006/RuoffAnnv.html | access-date = May 30, 2009 }}</ref> It is completely metallic at 155&nbsp;GPa.<ref>{{cite journal | vauthors = Eremets MI, Gregoryanz EA, Struzhkin VV, Mao HK, Hemley RJ, Mulders N, Zimmerman NM | title = Electrical Conductivity of Xenon at Megabar Pressures | journal = Physical Review Letters | volume = 85 | issue = 13 | pages = 2797–2800 | date = Sep 2000 | pmid = 10991236 | doi = 10.1103/PhysRevLett.85.2797 | bibcode = 2000PhRvL..85.2797E | s2cid = 19937739 }}</ref> When metallized, xenon appears sky blue because it absorbs red light and transmits other visible frequencies. Such behavior is unusual for a metal and is explained by the relatively small width of the electron bands in that state.<ref name="Fontes">{{cite web | vauthors = Fontes E | title = Golden Anniversary for Founder of High-pressure Program at CHESS | publisher = Cornell University | url = https://news.chess.cornell.edu/articles/2006/RuoffAnnv.html | access-date = May 30, 2009 }}</ref>{{Better citation needed|reason=The current source is self-published (by a university) and not primarily scientific|date=May 2024}}

[[File:Xenon-flash.gif|thumb|200px|Xenon flashing inside a [[flashtube]] frame by frame]]
Liquid or solid xenon [[nanoparticle]]s can be formed at room temperature by implanting Xe<sup>+</sup> ions into a solid matrix. Many solids have lattice constants smaller than solid Xe. This results in compression of the implanted Xe to pressures that may be sufficient for its liquefaction or solidification.<ref>{{cite journal | vauthors = Iakoubovskii K, Mitsuishi K, Furuya K | title = Structure and pressure inside Xe nanoparticles embedded in Al | journal = Physical Review B | volume = 78 | issue = 6 | article-number = 064105 | year = 2008 | doi = 10.1103/PhysRevB.78.064105 | s2cid = 29156048 | bibcode = 2008PhRvB..78f4105I | url = https://mdr.nims.go.jp/pid/0e7dcc69-b57a-41e3-8c29-470317925117 }}</ref>

Xenon is a member of the zero-[[Valence (chemistry)|valence]] elements that are called [[noble gas|noble]] or [[inert gas]]es. It is inert to most common chemical reactions (such as combustion, for example) because the outer [[valence shell]] contains eight electrons. This produces a stable, minimum energy configuration in which the outer electrons are tightly bound.<ref>{{cite web | vauthors = Bader RF | title = An Introduction to the Electronic Structure of Atoms and Molecules | url = http://miranda.chemistry.mcmaster.ca/esam/ | publisher = [[McMaster University]] | access-date = September 27, 2007 }}</ref>

In a [[gas-filled tube]], xenon emits a [[blue]] or [[lavender (color)|lavenderish]] glow when excited by [[Electric arc|electrical discharge]]. Xenon emits a band of [[Spectral line|emission lines]] that span the visual spectrum,<ref>{{cite web | vauthors = Talbot J | title = Spectra of Gas Discharges | url = http://web.physik.rwth-aachen.de/~harm/aixphysik/atom/discharge/index1.html | publisher = Rheinisch-Westfälische Technische Hochschule Aachen | access-date = August 10, 2006 | url-status = dead | archive-url = https://web.archive.org/web/20070718115616/http://web.physik.rwth-aachen.de/~harm/aixphysik/atom/discharge/index1.html | archive-date = July 18, 2007 }}</ref> but the most intense lines occur in the region of blue light, producing the coloration.<ref>{{cite book | vauthors = Watts WM | title = An Introduction to the Study of Spectrum Analysis | location = London | date = 1904 | url = https://archive.org/details/anintroductiont00hugggoog | publisher = [[Longmans, Green, and Co.]] }}</ref>

== Occurrence and production ==
Xenon is a [[trace gas]] in [[Earth's atmosphere]], occurring at a volume fraction of {{val|87|1|u=nL/L}} ([[parts per billion]]), or approximately 1 part per 11.5 million.<ref name="Hwang_2005">{{cite book | vauthors = Hwang SC, Lein RD, Morgan DA | chapter = Noble Gases | title = Kirk-Othmer Encyclopedia of Chemical Technology | year = 2005 | doi = 10.1002/0471238961.0701190508230114.a01 | publisher = [[John Wiley & Sons | Wiley]] | edition = 5th | isbn = 978-0-471-48511-7 }}</ref> It is also found as a component of gases emitted from some [[mineral spring]]s. Given a total mass of the atmosphere of {{convert|5.15e18|kg}}, the atmosphere contains on the order of {{convert|2.03|Gt}} of xenon in total when taking the average molar mass of the atmosphere as 28.96&nbsp;g/mol which is equivalent to some 394-mass ppb.

=== The missing Xe problem ===
The concentration of Xe in the atmosphere is much lower than Ar and Kr, a geological mystery known as "the missing Xe problem". Numerous proposals have been made to explain the mystery, including formation of Xe–Fe oxides in the Earth's lower mantle,<ref>{{Cite journal | vauthors = Peng F, Song X, Liu C, Li Q, Miao M, Chen C, Ma Y | title = Xenon iron oxides predicted as potential Xe hosts in Earth's lower mantle | journal = Nature Communications | volume = 11 | issue = 1 | article-number = 5227 | date = October 16, 2020 | pmid = 33067445 | pmc = 7568531 | doi = 10.1038/s41467-020-19107-y | language = en | issn = 2041-1723 | bibcode = 2020NatCo..11.5227P }}</ref> formation of xenon dioxide in silica,<ref>{{Cite journal | vauthors = Brock DS, Schrobilgen GJ | title = Synthesis of the Missing Oxide of Xenon, XeO2, and Its Implications for Earth's Missing Xenon | journal = Journal of the American Chemical Society | volume = 133 | issue = 16 | pages = 6265–6269 | date = April 27, 2011 | pmid = 21341650 | doi = 10.1021/ja110618g | url = https://pubs.acs.org/doi/10.1021/ja110618g | bibcode = 2011JAChS.133.6265B | issn = 0002-7863 | url-access = subscription }}</ref> and reactions between Xe and Fe/Ni in the Earth's core.<ref>{{Cite journal | vauthors = Zhu L, Liu H, Pickard CJ, Zou G, Ma Y | title = Reactions of xenon with iron and nickel are predicted in the Earth's inner core | journal = Nature Chemistry | volume = 6 | issue = 7 | pages = 644–648 | date = July 2014 | pmid = 24950336 | doi = 10.1038/nchem.1925 | url = https://www.nature.com/articles/nchem.1925 | language = en | issn = 1755-4349 | arxiv = 1309.2169 | bibcode = 2014NatCh...6..644Z }}</ref>

=== Commercial ===
Xenon is obtained commercially as a by-product of the [[air separation|separation of air]] into [[oxygen]] and [[nitrogen]].<ref>{{cite journal | vauthors = Lebedev PK, Pryanichnikov VI | title = Present and future production of xenon and krypton in the former USSR region and some physical properties of these gases | journal = Nuclear Instruments and Methods in Physics Research A | volume = 327 | issue = 1 | pages = 222–226 | year = 1993 | doi = 10.1016/0168-9002(93)91447-U | url = https://www.nevis.columbia.edu/~ju/Paper/Paper-detector/science16.pdf | bibcode = 1993NIMPA.327..222L }}</ref> After this separation, generally performed by [[fractional distillation]] in a double-column plant, the [[liquid oxygen]] produced will contain small quantities of [[krypton]] and xenon. By additional fractional distillation, the liquid oxygen may be enriched to contain 0.1–0.2% of a krypton/xenon mixture, which is extracted either by [[adsorption]] onto [[silica gel]] or by distillation. Finally, the krypton/xenon mixture may be separated into krypton and xenon by further distillation.<ref>{{cite book | vauthors = Kerry FG | title = Industrial Gas Handbook: Gas Separation and Purification | pages = 101–103 | date = 2007 | publisher = CRC Press | isbn = 978-0-8493-9005-0 | url = https://books.google.com/books?id=cXNmyTTGbRIC&pg=PA101 }}</ref><ref>{{cite web | title = Xenon – Xe | date = August 10, 1998 | url = http://www.c-f-c.com/specgas_products/xenon.htm | access-date = September 7, 2007 | publisher = CFC StarTec LLC | archive-date = June 12, 2020 | archive-url = https://web.archive.org/web/20200612100905/http://www.c-f-c.com/specgas_products/xenon.htm | url-status = dead }}</ref>

Worldwide production of xenon in 1998 was estimated at {{convert|5,000–7,000|m3}}.<ref name="Haussinger_2001">{{cite book | vauthors = Häussinger P, Glatthaar R, Rhode W, Kick H, Benkmann C, Weber J, Wunschel HJ, Stenke V, Leicht E, Stenger H | chapter = Noble Gases | title = Ullmann's Encyclopedia of Industrial Chemistry | year = 2001 | doi = 10.1002/14356007.a17_485 | publisher = Wiley | edition = 6th | isbn = 978-3-527-20165-5 }}</ref> At a density of {{Convert|5.894|g/L}} this is equivalent to roughly {{Convert|30 to 40|t}}. Because of its scarcity, xenon is much more expensive than the lighter noble gases—approximate prices for the purchase of small quantities in Europe in 1999 were 10&nbsp;[[Euro|€]]/L (=~€1.7/g) for xenon, 1&nbsp;€/L (=~€0.27/g) for krypton, and 0.20&nbsp;€/L (=~€0.22/g) for neon,<ref name="Haussinger_2001" /> while the much more plentiful argon, which makes up over 1% by volume of earth's atmosphere, costs less than a cent per liter.

=== Solar System ===
Within the Solar System, the [[nucleon]] fraction of xenon is {{val|1.56|e=-8}}, for an [[Abundance of the chemical elements|abundance]] of approximately one part in 630&nbsp;thousand of the total mass.<ref>{{cite book | vauthors = Arnett D | title = Supernovae and Nucleosynthesis | location = Princeton, [[New Jersey | NJ]] | date = 1996 | publisher = [[Princeton University Press]] | isbn = 978-0-691-01147-9 | url = https://books.google.com/books?id=PXGWGnPPo0gC&pg=PA30 }}</ref> Xenon is relatively rare in the [[Sun]]'s atmosphere, on [[Earth]], and in [[asteroid]]s and [[comet]]s. The abundance of xenon in the atmosphere of planet [[Jupiter]] is unusually high, about 2.6 times that of the Sun.<ref name="Mahaffy_2000">{{cite journal | vauthors = Mahaffy PR, Niemann HB, Alpert A, Atreya SK, Demick J, Donahue TM, Harpold DN, Owen TC | title = Noble gas abundance and isotope ratios in the atmosphere of Jupiter from the Galileo Probe Mass Spectrometer | journal = Journal of Geophysical Research | volume = 105 | issue = E6 | pages = 15061–15072 | date = 2000 | doi = 10.1029/1999JE001224 | bibcode = 2000JGR...10515061M | doi-access = free }}</ref>{{efn | Mass fraction calculated from the average mass of an atom in the Solar System of about 1.29 atomic mass units.}} This abundance remains unexplained, but may have been caused by an early and rapid buildup of [[planetesimal]]s—small, sub-planetary bodies—before the heating of the [[solar nebula|presolar disk]];<ref>{{cite journal | vauthors = Owen T, Mahaffy P, Niemann HB, Atreya S, Donahue T, Bar-Nun A, de Pater I | title = A low-temperature origin for the planetesimals that formed Jupiter | journal = Nature | volume = 402 | issue = 6759 | pages = 269–270 | date = Nov 1999 | pmid = 10580497 | doi = 10.1038/46232 | s2cid = 4426771 | bibcode = 1999Natur.402..269O | hdl = 2027.42/62913 | url = https://deepblue.lib.umich.edu/bitstream/2027.42/62913/1/402269a0.pdf | hdl-access = free }}</ref> otherwise, xenon would not have been trapped in the planetesimal ices. The problem of the low terrestrial xenon may be explained by [[covalent bond]]ing of xenon to oxygen within [[quartz]], reducing the [[outgassing]] of xenon into the atmosphere.<ref>{{cite journal | vauthors = Sanloup C, Schmidt BC, Perez EM, Jambon A, Gregoryanz E, Mezouar M | title = Retention of Xenon in Quartz and Earth's Missing Xenon | journal = Science | volume = 310 | issue = 5751 | pages = 1174–1177 | date = Nov 2005 | pmid = 16293758 | doi = 10.1126/science.1119070 | s2cid = 31226092 | bibcode = 2005Sci...310.1174S }}</ref>

=== Stellar ===
Unlike the lower-mass noble gases, the normal [[stellar nucleosynthesis]] process inside a star does not form xenon. Nucleosynthesis consumes energy to produce nuclides more massive than [[iron-56]], and thus the synthesis of xenon represents no energy gain for a star.<ref>{{cite book | vauthors = Clayton DD | title = Principles of Stellar Evolution and Nucleosynthesis | pages = [https://archive.org/details/principlesofstel0000clay/page/604 604] | date = 1983 | publisher = [[University of Chicago Press]] | isbn = 978-0-226-10953-4 | url = https://archive.org/details/principlesofstel0000clay | url-access = registration }}</ref> Instead, xenon is formed during [[supernova]] explosions during the [[r-process]],<ref name="Heymann_1979">{{cite conference | vauthors = Heymann D, Dziczkaniec M | title = Xenon from intermediate zones of supernovae | location = Houston, Texas | pages = 1943–1959 | date = March 19–23, 1979 | work = Proceedings 10th Lunar and Planetary Science Conference | publisher = Pergamon Press, Inc. | bibcode = 1979LPSC...10.1943H }}</ref> by the slow neutron-capture process ([[s-process]]) in [[red giant]] stars that have exhausted their core hydrogen and entered the [[asymptotic giant branch]],<ref>{{cite journal | vauthors = Beer H, Kaeppeler F, Reffo G, Venturini G | title = Neutron capture cross-sections of stable xenon isotopes and their application in stellar nucleosynthesis | journal = Astrophysics and Space Science | volume = 97 | issue = 1 | pages = 95–119 | date = November 1983 | doi = 10.1007/BF00684613 | s2cid = 123139238 | bibcode = 1983Ap&SS..97...95B }}</ref> and from radioactive decay, for example by [[beta decay]] of [[extinct radionuclide|extinct]] [[iodine-129]] and [[spontaneous fission]] of [[thorium]], [[uranium]], and [[plutonium]].<ref name="Caldwell_2004" />

=== Nuclear fission ===
[[File:Fission yield volatile 2.png|thumb|class=skin-invert-image|Fission product yields from nuclear fission of <sup>235</sup>U with thermal neutrons. Xenon is represented by the tallest blue bar in the graph]]

[[Xenon-135]] is a notable [[neutron poison]] with a high [[fission product yield]]. As it is relatively short lived, it decays at the same rate it is produced during ''steady'' operation of a nuclear reactor. However, if power is reduced or the reactor is [[scram]]med, less xenon is destroyed than is produced from the beta decay of its [[parent nuclide]]s. This phenomenon called [[xenon poisoning]] can cause significant problems in restarting a reactor after a scram or increasing power after it had been reduced and it was one of several contributing factors in the [[Chernobyl nuclear accident]].<ref>{{cite web | title = "Xenon Poisoning" or Neutron Absorption in Reactors | url = http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/xenon.html }}</ref><ref>{{cite web | title = Chernobyl Appendix 1: Sequence of Events – World Nuclear Association | url = https://world-nuclear.org/information-library/safety-and-security/safety-of-plants/appendices/chernobyl-accident-appendix-1-sequence-of-events.aspx }}</ref>

Stable or extremely long lived isotopes of xenon are also produced in appreciable quantities in nuclear fission. Xenon-136 is produced both as a fission product and when xenon-135 undergoes [[neutron capture]] before it can decay. The ratio of xenon-136 to xenon-135 (or its decay products) can give hints as to the power history of a given reactor or identify a nuclear explosion, as xenon-135 is mostly produced by successive beta decays of more neutron-rich fission products. These short-lived nuclides do not share its neutron-absorbing prowess, and so absorb fewer neutrons during the brief moment of a nuclear explosion, lowering the ratio of mass-136 to mass-135 products.<ref>{{Cite journal | vauthors = Lee SK, Beyer GJ, Lee JS | title = Development of Industrial-Scale Fission 99Mo Production Process Using Low Enriched Uranium Target | journal = Nuclear Engineering and Technology | volume = 48 | issue = 3 | pages = 613–623 | year = 2016 | doi = 10.1016/j.net.2016.04.006 | doi-access = free }}</ref>

The stable isotope xenon-132 has a fission product yield of over 4% in the [[thermal neutron]] fission of {{chem|235|U}} which means that stable or nearly stable xenon isotopes have a higher mass fraction in [[spent nuclear fuel]] (which is about 3% fission products in the case of [[light water reactor]]s) than it does in air. However, there is as of 2022 no commercial effort to extract xenon from spent fuel during [[nuclear reprocessing]].<ref>{{Cite web | title = Novel gas-capture approach advances nuclear fuel management | date = July 24, 2020 | url = https://news.mit.edu/2020/novel-gas-capture-approach-advances-nuclear-fuel-management-0724 }}</ref><ref>{{Cite web | title = What's in Spent Nuclear Fuel? (After 20 yrs) – Energy from Thorium | date = June 22, 2010 | url = https://energyfromthorium.com/2010/06/22/whats-in-spent-nuclear-fuel-after-20-yrs/ }}</ref>

== Isotopes ==
{{Main|Isotopes of xenon}}
Naturally occurring xenon is composed of seven [[stable isotope|stable]] and two [[primordial radionuclide|almost stable]] [[isotope]]s: <sup>126</sup>Xe, <sup>128–132</sup>Xe, and <sup>134</sup>Xe are stable, <sup>124</sup>Xe and <sup>136</sup>Xe have very long half-lives, trillions of times the age of the universe. The isotopes <sup>126</sup>Xe<ref>{{cite journal | vauthors = Akerib DS | title = Search for two neutrino double electron capture of <sup>124</sup>Xe and <sup>126</sup>Xe in the full exposure of the LUX detector | journal = Journal of Physics G: Nuclear and Particle Physics | volume = 47 | issue = 10 | pages = 105105 | date = 2020-10-01 | doi = 10.1088/1361-6471/ab9c2d | issn = 0954-3899 | arxiv = 1912.02742 | bibcode = 2020JPhG...47j5105A }}</ref> and <sup>134</sup>Xe<ref>{{cite journal | vauthors = Yan X, Cheng Z, Abdukerim A, Bo Z, Chen W, Chen X, Cheng C, Cui X, Fan Y, Fang D, Fu C, Fu M, Geng L, Giboni K, Gu L, Guo X, Han C, Han K, He C, He J, Huang D, Huang Y, Huang J, Huang Z, Hou R, Hou Y, Ji X, Ju Y, Li C, Li J, Li M, Li S, Li T, Lin Q, Liu J, Lu X, Lu C, Luo L, Luo Y, Ma W, Ma Y, Mao Y, Meng Y, Ning X, Pang B, Qi N, Qian Z, Ren X, Shaheed N, Shang X, Shao X, Shen G, Si L, Sun W, Tan A, Tao Y, Wang A, Wang M, Wang Q, Wang S, Wang S, Wang W, Wang X, Wang Z, Wei Y, Wu M, Wu W, Xia J, Xiao M, Xiao X, Xie P, Yan B, Yang J, Yang Y, Yao Y, Yu C, Yuan Y, Yuan Z, Zeng X, Zhang D, Zhang M, Zhang P, Zhang S, Zhang S, Zhang T, Zhang W, Zhang Y, Zhang Y, Zhang Y, Zhao L, Zheng Q, Zhou J, Zhou N, Zhou X, Zhou Y, Zhou Y | title = Searching for two-neutrino and neutrinoless double beta decay of <sup>134</sup>Xe with the PandaX-4T experiment | journal = Physical Review Letters | volume = 132 | issue = 15 | article-number = 152502 | date = 2024 | pmid = 38682998 | doi = 10.1103/PhysRevLett.132.152502 | arxiv = 2312.15632 | bibcode = 2024PhRvL.132o2502Y }}</ref> are also predicted by theory to undergo [[double beta decay]], but this has never been observed so they are considered stable.

More than 40 unstable isotopes are known. The longest-lived of these isotopes are the [[primordial nuclide|primordial]] <sup>124</sup>Xe, which undergoes [[double electron capture]] with a half-life of {{val|1.1|e=22|u=yr}}, and <sup>136</sup>Xe, which undergoes double beta decay with a half-life of {{val|2.18|e=21|u=yr}}.{{NUBASE2020|ref}}

<sup>129</sup>Xe is produced by [[beta decay]] of <sup>129</sup>[[iodine|I]], which has a [[half-life]] of 16.1&nbsp;million years. <sup>131m</sup>Xe, <sup>133</sup>Xe, <sup>133m</sup>Xe, and <sup>135</sup>Xe are some of the [[nuclear fission|fission]] products of <sup>235</sup>[[uranium|U]] and <sup>239</sup>[[plutonium|Pu]],<ref name="Caldwell_2004">{{cite web | vauthors = Caldwell E | title = Periodic Table – Xenon | date = January 2004 | url = https://wwwrcamnl.wr.usgs.gov/isoig/period/xe_iig.html | work = Resources on Isotopes | publisher = USGS | access-date = October 8, 2007 | archive-date = December 13, 2013 | archive-url = https://web.archive.org/web/20131213053952/http://wwwrcamnl.wr.usgs.gov/isoig/period/xe_iig.html | url-status = dead }}</ref> and are used to detect and monitor nuclear explosions.

=== Nuclear spin ===
Nuclei of the stable isotopes with odd mass number, <sup>129</sup>Xe and <sup>131</sup>Xe have non-zero intrinsic [[angular momentum|angular momenta]] ([[Spin (physics)|nuclear spins]], suitable for [[nuclear magnetic resonance]]). The nuclear spins can be aligned beyond ordinary polarization levels by means of circularly polarized light and [[rubidium]] vapor.<ref>{{cite journal | vauthors = Otten EW | title = Take a breath of polarized noble gas | journal = Europhysics News | volume = 35 | issue = 1 | pages = 16–20 | date = 2004 | doi = 10.1051/epn:2004109 | s2cid = 51224754 | bibcode = 2004ENews..35...16O | doi-access = free }}</ref> The resulting [[spin polarization]] of xenon [[atomic nucleus|nuclei]] can surpass 50% of its maximum possible value, greatly exceeding the thermal equilibrium value dictated by [[paramagnetic]] statistics (typically 0.001% of the maximum value at [[room temperature]], even in the strongest [[magnet]]s). Such non-equilibrium alignment of spins is a temporary condition, and is called ''[[hyperpolarization (physics)|hyperpolarization]]''. The process of hyperpolarizing the xenon is called ''optical pumping'' (although the process is different from [[optical pumping|pumping a laser]]).<ref>{{cite journal | vauthors = Ruset IC, Ketel S, Hersman FW | title = Optical Pumping System Design for Large Production of Hyperpolarized <sup>129</sup>Xe | journal = Physical Review Letters | volume = 96 | issue = 5 | article-number = 053002 | date = Feb 2006 | pmid = 16486926 | doi = 10.1103/PhysRevLett.96.053002 | bibcode = 2006PhRvL..96e3002R }}</ref>

Because a <sup>129</sup>Xe nucleus has a [[Spin (physics)|spin]] of 1/2, and therefore a zero [[electric field|electric]] [[quadrupole moment]], the <sup>129</sup>Xe nucleus does not experience any quadrupolar interactions during collisions with other atoms, and the hyperpolarization persists for long periods even after the engendering light and vapor have been removed. Spin polarization of <sup>129</sup>Xe can persist from several [[second]]s for xenon atoms dissolved in [[blood]]<ref>{{cite journal | vauthors = Wolber J, Cherubini A, Leach MO, Bifone A | title = On the oxygenation-dependent <sup>129</sup>Xe t<sub>1</sub> in blood | journal = [[NMR in Biomedicine]] | volume = 13 | issue = 4 | pages = 234–237 | date = Jun 2000 | pmid = 10867702 | doi = 10.1002/1099-1492(200006)13:4<234::AID-NBM632>3.0.CO;2-K | s2cid = 94795359 | doi-access = free }}</ref> to several hours in the [[gas phase]]<ref>{{cite journal | vauthors = Chann B, Nelson IA, Anderson LW, Driehuys B, Walker TG | title = <sup>129</sup>Xe–Xe molecular spin relaxation | journal = Physical Review Letters | volume = 88 | issue = 11 | article-number = 113201 | date = Mar 2002 | pmid = 11909399 | doi = 10.1103/PhysRevLett.88.113201 | bibcode = 2002PhRvL..88k3201C }}</ref> and several days in deeply frozen solid xenon.<ref>{{cite encyclopedia | vauthors = von Schulthess GK, Smith HJ, Pettersson H, Allison DJ | title = The Encyclopaedia of Medical Imaging | pages = 194 | year = 1998 | publisher = Taylor & Francis | isbn = 978-1-901865-13-4 | url = https://books.google.com/books?id=zvDY5unRC4oC&pg=PA194 }}</ref> In contrast, [[isotopes of xenon|<sup>131</sup>Xe]] has a nuclear spin value of {{frac|3|2}} and a nonzero quadrupole moment, and has t<sub>1</sub> relaxation times in the [[millisecond]] and second ranges.<ref>{{cite journal | vauthors = Warren WW, Norberg RE | title = Nuclear Quadrupole Relaxation and Chemical Shift of Xe<sup>131</sup> in Liquid and Solid Xenon | journal = Physical Review | volume = 148 | issue = 1 | pages = 402–412 | year = 1966 | doi = 10.1103/PhysRev.148.402 | bibcode = 1966PhRv..148..402W }}</ref>

=== From fission ===
Some radioactive isotopes of xenon (for example, <sup>133</sup>Xe and <sup>135</sup>Xe) are produced by [[neutron]] irradiation of fissionable material within [[nuclear reactor]]s.<ref name="Husted_2003" /> [[Xenon-135|<sup>135</sup>Xe]] is of considerable significance in the operation of nuclear fission reactors. <sup>135</sup>Xe has a huge [[Neutron cross-section|cross section]] for [[thermal neutron]]s, 2.6 million&nbsp;[[Barn (unit)|barns]],<ref name="Stacey_2007">{{cite book | vauthors = Stacey WM | title = Nuclear Reactor Physics | pages = 213 | date = 2007 | url = https://books.google.com/books?id=y1UgcgVSXSkC&pg=PA213 | publisher = Wiley-VCH | isbn = 978-3-527-40679-1 }}</ref> and operates as a [[neutron absorber]] or "[[nuclear poison|poison]]" that can slow or stop the chain reaction after a period of operation. This was discovered in the earliest nuclear reactors built by the American [[Manhattan Project]] for [[plutonium]] production. However, the designers had made provisions in the design to increase the reactor's reactivity (the number of neutrons per fission that go on to fission other atoms of [[nuclear fuel]]).<ref>{{cite web | vauthors = Staff | title = Hanford Becomes Operational | url = http://www.cfo.doe.gov/me70/manhattan/hanford_operational.htm | archive-url = https://web.archive.org/web/20091210094859/http://www.cfo.doe.gov/me70/manhattan/hanford_operational.htm | archive-date = December 10, 2009 | work = The Manhattan Project: An Interactive History | publisher = U.S. Department of Energy | access-date = October 10, 2007 }}</ref>

<sup>135</sup>Xe reactor poisoning was a major factor in the [[Chernobyl disaster]].<ref>{{cite book | vauthors = Pfeffer JI, Nir S | title = Modern Physics: An Introductory Text | pages = 421 ff | date = 2000 | publisher = [[Imperial College Press]] | isbn = 978-1-86094-250-1 | url = https://books.google.com/books?id=KmMYWP56t98C&pg=PA421 }}</ref> A shutdown or decrease of power of a reactor can result in buildup of <sup>135</sup>Xe, with reactor operation going into a condition known as the [[iodine pit]]. Under adverse conditions, relatively high concentrations of radioactive xenon isotopes may emanate from cracked [[fuel rod]]s,<ref>{{cite book | vauthors = Laws EA | title = Aquatic Pollution: An Introductory Text | pages = 505 | date = 2000 | publisher = John Wiley and Sons | isbn = 978-0-471-34875-7 | url = https://books.google.com/books?id=11LI7XyEIsAC&pg=PA505 }}</ref> or fissioning of uranium in [[Water cooling|cooling water]].<ref>{{cite news | vauthors = Staff | title = A Nuclear Nightmare | date = April 9, 1979 | magazine = [[Time (magazine) | Time]] | url = http://www.time.com/time/magazine/article/0,9171,920196-4,00.html | archive-url = https://web.archive.org/web/20071012190713/http://www.time.com/time/magazine/article/0,9171,920196-4,00.html | url-status = dead | archive-date = October 12, 2007 | access-date = October 9, 2007 }}</ref>

Isotope ratios of xenon produced in [[natural nuclear fission reactor]]s at [[Oklo]] in Gabon reveal the reactor properties during the chain reaction that took place about 2 billion years ago.<ref name="Meshik PRL 2004">{{cite journal | vauthors = Meshik AP, Hohenberg CM, Pravdivtseva OV | title = Record of Cycling Operation of the Natural Nuclear Reactor in the Oklo/Okelobondo Area in Gabon | journal = Phys. Rev. Lett. | volume = 93 | issue = 18 | article-number = 182302 | date = 2004 | pmid = 15525157 | doi = 10.1103/physrevlett.93.182302 | issn = 0031-9007 | bibcode = 2004PhRvL..93r2302M }}</ref>

=== Cosmic processes ===
Because xenon is a tracer for two parent isotopes, xenon isotope ratios in [[meteorite]]s are a powerful tool for studying the [[formation of the Solar System]]. The [[Iodine–xenon dating|iodine–xenon method]] of [[Radiometric dating|dating]] gives the time elapsed between [[nucleosynthesis]] and the condensation of a solid object from the [[solar nebula]]. In 1960, physicist [[John Reynolds (physicist)|John H. Reynolds]] discovered that certain meteorites contained an isotopic anomaly in the form of an overabundance of xenon-129. He inferred that this was a [[decay product]] of radioactive [[iodine-129]]. This isotope is produced slowly by [[cosmic ray spallation]] and [[nuclear fission]], but is produced in quantity only in supernova explosions.<ref name="Clayton 1983 75">{{cite book | vauthors = Clayton DD | title = Principles of Stellar Evolution and Nucleosynthesis | pages = [https://archive.org/details/principlesofstel0000clay/page/75 75] | date = 1983 | edition = 2nd | url = https://archive.org/details/principlesofstel0000clay | url-access = registration | publisher = University of Chicago Press | isbn = 978-0-226-10953-4 }}</ref><ref name="Bolt, B. A. 2007">{{cite web | vauthors = Bolt BA, Packard RE, Price PB | title = John H. Reynolds, Physics: Berkeley | year = 2007 | url = http://content.cdlib.org/xtf/view?docId=hb1r29n709&doc.view=content&chunk.id=div00061&toc.depth=1&brand=oac&anchor.id=0 | publisher = [[The University of California, Berkeley]] | access-date = October 1, 2007 }}</ref>

Because the half-life of <sup>129</sup>I is comparatively short on a cosmological time scale (~16 million years), this demonstrated that only a short time had passed between the supernova and the time the meteorites had solidified and trapped the <sup>129</sup>I. These two events (supernova and solidification of gas cloud) were inferred to have happened during the early history of the [[Solar System]], because the <sup>129</sup>I isotope was likely generated shortly before the Solar System was formed, seeding the solar gas cloud with isotopes from a second source. This supernova source may also have caused collapse of the solar gas cloud.<ref name="Clayton 1983 75" /><ref name="Bolt, B. A. 2007" />

In a similar way, xenon isotopic ratios such as <sup>129</sup>Xe/<sup>130</sup>Xe and <sup>136</sup>Xe/<sup>130</sup>Xe are a powerful tool for understanding planetary differentiation and early outgassing.<ref name="Kaneoka_1998">{{cite journal | vauthors = Kaneoka I | title = Xenon's Inside Story | journal = Science | volume = 280 | issue = 5365 | pages = 851–852 | year = 1998 | doi = 10.1126/science.280.5365.851b | s2cid = 128502357 }}</ref> For example, the [[atmosphere of Mars]] shows a xenon abundance similar to that of Earth (0.08&nbsp;parts per million<ref>{{cite web | vauthors = Williams DR | title = Mars Fact Sheet | date = September 1, 2004 | url = http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html | publisher = NASA | access-date = October 10, 2007 | archive-url = https://web.archive.org/web/20100612092806/http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html | archive-date = June 12, 2010 | url-status = dead }}</ref>) but Mars shows a greater abundance of <sup>129</sup>Xe than the Earth or the Sun. Since this isotope is generated by radioactive decay, the result may indicate that Mars lost most of its primordial atmosphere, possibly within the first 100 million years after the planet was formed.<ref>{{cite web | vauthors = Schilling J | title = Why is the Martian atmosphere so thin and mainly carbon dioxide? | url = http://humbabe.arc.nasa.gov/mgcm/HTML/FAQS/thin_atm.html | publisher = Mars Global Circulation Model Group | access-date = October 10, 2007 | url-status = dead | archive-url = https://web.archive.org/web/20100528010109/http://humbabe.arc.nasa.gov/mgcm/HTML/FAQS/thin_atm.html | archive-date = May 28, 2010 }}</ref><ref>{{cite journal | vauthors = Zahnle KJ | title = Xenological constraints on the impact erosion of the early Martian atmosphere | journal = [[Journal of Geophysical Research]] | volume = 98 | issue = E6 | pages = 10,899–10,913 | year = 1993 | doi = 10.1029/92JE02941 | bibcode = 1993JGR....9810899Z | url = https://zenodo.org/record/1231333 }}</ref> In another example, excess <sup>129</sup>Xe found in [[carbon dioxide]] well gases from [[New Mexico]] is believed to be from the decay of [[Mantle (geology)|mantle]]-derived gases from soon after Earth's formation.<ref name="Caldwell_2004" /><ref>{{cite journal | vauthors = Boulos MS, Manuel O | title = The xenon record of extinct radioactivities in the Earth | journal = [[science (journal) | science]] | volume = 174 | issue = 4016 | pages = 1334–1336 | date = 1971 | pmid = 17801897 | doi = 10.1126/science.174.4016.1334 | s2cid = 28159702 | bibcode = 1971Sci...174.1334B }}</ref>

== Compounds ==
{{Main article|Xenon compounds}}
{{Category see also|Xenon compounds}}
After Neil Bartlett's discovery in 1962 that xenon can form chemical compounds, a large number of xenon compounds have been discovered and described. Almost all known xenon compounds contain the [[electronegative]] atoms fluorine or oxygen. The chemistry of xenon in each oxidation state is analogous to that of the neighboring element [[iodine]] in the immediately lower oxidation state.<ref name="Harding_2002" />

=== Halides ===
[[File:Xenon-tetrafluoride-3D-vdW.png|thumb|class=bg-transparent|[[Xenon tetrafluoride]] | alt=A model of planar chemical molecule with a blue center atom (Xe) symmetrically bonded to four peripheral atoms (fluorine).]]

[[File:Xenon tetrafluoride.png|thumb|XeF<sub>4</sub> crystals, 1962|alt=Many cubic transparent crystals in a petri dish.]]

Three [[fluoride]]s are known: [[xenon difluoride|{{chem|XeF|2}}]], [[xenon tetrafluoride|{{chem|XeF|4}}]], and [[xenon hexafluoride|{{chem|XeF|6}}]]. These are the starting points for the synthesis of almost all xenon compounds.

The solid, crystalline difluoride {{chem|XeF|2}} is formed when a mixture of [[fluorine]] and xenon gases is exposed to ultraviolet light.<ref>{{cite journal | vauthors = Weeks JL, Chernick C, Matheson MS | title = Photochemical Preparation of Xenon Difluoride | journal = Journal of the American Chemical Society | volume = 84 | issue = 23 | pages = 4612–4613 | year = 1962 | doi = 10.1021/ja00882a063 | bibcode = 1962JAChS..84.4612W }}</ref> The ultraviolet component of ordinary daylight is sufficient.<ref>{{cite journal | vauthors = Streng LV, Streng AG | title = Formation of Xenon Difluoride from Xenon and Oxygen Difluoride or Fluorine in Pyrex Glass at Room Temperature | journal = Inorganic Chemistry | volume = 4 | issue = 9 | pages = 1370–1371 | year = 1965 | doi = 10.1021/ic50031a035 }}</ref> Long-term heating of {{chem|XeF|2}} at high temperatures under an {{chem|NiF|2}} catalyst yields {{chem|XeF|6}}.<ref name="Tramsek_2006">{{cite journal | vauthors = Tramšek M, Žemva B | title = Synthesis, Properties and Chemistry of Xenon(II) Fluoride | journal = Acta Chimica Slovenica | volume = 53 | issue = 2 | pages = 105–116 | date = December 5, 2006 | article-number = chin.200721209 | doi = 10.1002/chin.200721209 }}</ref> Pyrolysis of {{chem|XeF|6}} in the presence of [[sodium fluoride|NaF]] yields high-purity {{chem|XeF|4}}.<ref>{{cite journal | vauthors = Ogrin T, Bohinc M, Silvnik J | title = Melting-point determinations of xenon difluoride-xenon tetrafluoride mixtures | journal = [[Journal of Chemical and Engineering Data]] | volume = 18 | issue = 4 | pages = 402 | year = 1973 | doi = 10.1021/je60059a014 }}</ref>

The xenon fluorides behave as both fluoride acceptors and fluoride donors, forming salts that contain such cations as {{chem |XeF|+}} and {{chem |Xe}}{{su |b= 2}}{{chem |F|3|+}}, and anions such as {{chem |XeF|5|-}}, {{chem |XeF|7|-}}, and {{chem |XeF|8|2-}}. The green, paramagnetic {{chem |Xe|2|+}} is formed by the reduction of {{chem|XeF|2}} by xenon gas.<ref name="Harding_2002">{{cite book | vauthors = Harding C, Johnson DA, Janes R | title = Elements of the ''p'' block | location = Great Britain | pages = 93–94 | date = 2002 | publisher = Royal Society of Chemistry | isbn = 978-0-85404-690-4 | url = https://books.google.com/books?id=W0HW8wgmQQsC&pg=PA93 }}</ref>

{{chem|XeF|2}} also forms [[complex (chemistry)|coordination complexes]] with transition metal ions. More than 30 such complexes have been synthesized and characterized.<ref name="Tramsek_2006" />

Whereas the xenon fluorides are well characterized, the other halides are not. [[Xenon dichloride]], formed by the high-frequency irradiation of a mixture of xenon, fluorine, and [[silicon tetrachloride|silicon]] or [[carbon tetrachloride]],<ref name="Scott_1994">{{cite encyclopedia | vauthors = Scott T, Eagleson M | title = Xenon Compounds | pages = 1183 | year = 1994 | encyclopedia = Concise encyclopedia chemistry | publisher = [[Walter de Gruyter]] | url = https://books.google.com/books?id=Owuv-c9L_IMC&pg=PA1183 | isbn = 978-3-11-011451-5 }}</ref> is reported to be an endothermic, colorless, crystalline compound that decomposes into the elements at 80&nbsp;°C. However, {{chem|XeCl|2}} may be merely a [[van der Waals molecule]] of weakly bound Xe atoms and {{chem |Cl|2}} molecules and not a real compound.<ref>{{cite journal | vauthors = Proserpio DM, Hoffmann R, Janda KC | title = The xenon-chlorine conundrum: van der Waals complex or linear molecule? | journal = Journal of the American Chemical Society | volume = 113 | issue = 19 | pages = 7184–7189 | year = 1991 | doi = 10.1021/ja00019a014 | bibcode = 1991JAChS.113.7184P }}</ref> Theoretical calculations indicate that the linear molecule {{chem|XeCl|2}} is less stable than the van der Waals complex.<ref>{{cite journal | vauthors = Richardson NA, Hall MB | title = The potential energy surface of xenon dichloride | journal = The Journal of Physical Chemistry | volume = 97 | issue = 42 | pages = 10952–10954 | year = 1993 | doi = 10.1021/j100144a009 | bibcode = 1993JPhCh..9710952R }}</ref> [[Xenon tetrachloride]] and [[xenon dibromide]] are even more unstable and they cannot be synthesized by chemical reactions. They were created by [[radioactive decay]] of {{chem |129|ICl|4|-}} and {{chem |129|IBr|2|-}}, respectively.<ref name="book bell2013syntheses">{{cite book | vauthors = Bell C | title = Syntheses and Physical Studies of Inorganic Compounds | pages = 143 | year = 2013 | isbn = 978-1-4832-8060-8 | publisher = Elsevier Science }}</ref><ref name="book cockett2013chemistry">{{Cite book | vauthors = Cockett A, Smith K, Bartlett N | title = The Chemistry of the Monatomic Gases: Pergamon Texts in Inorganic Chemistry | pages = 292 | year = 2013 | isbn = 978-1-4831-5736-8 | publisher = Elsevier Science }}</ref>

=== Oxides and oxohalides ===
Three oxides of xenon are known: [[xenon trioxide]] ({{chem|XeO|3}}) and [[xenon tetroxide]] ({{chem|XeO|4}}), both of which are dangerously explosive and powerful oxidizing agents, and [[xenon dioxide]] (XeO<sub>2</sub>), which was reported in 2011 with a [[coordination number]] of four.<ref>{{cite journal | vauthors = Brock D, Schrobilgen G | title = Synthesis of the missing oxide of xenon, XeO<sub>2</sub>, and its implications for Earth's missing xenon | journal = [[Journal of the American Chemical Society]] | volume = 133 | issue = 16 | pages = 6265–6269 | date = Apr 2011 | pmid = 21341650 | doi = 10.1021/ja110618g | bibcode = 2011JAChS.133.6265B }}</ref> XeO<sub>2</sub> forms when xenon tetrafluoride is poured over ice. Its crystal structure may allow it to replace silicon in silicate minerals.<ref name="ChemistryWhere2011">{{Cite journal | title = Chemistry: Where did the xenon go? | journal = Nature | volume = 471 | issue = 7337 | pages = 138 | year = 2011 | doi = 10.1038/471138d | bibcode = 2011Natur.471T.138. | doi-access = free }}</ref> The XeOO<sup>+</sup> cation has been identified by [[infrared spectroscopy]] in solid [[argon]].<ref>{{cite journal | vauthors = Zhou M, Zhao Y, Gong Y, Li J | title = Formation and Characterization of the XeOO<sup>+</sup> Cation in Solid Argon | journal = [[Journal of the American Chemical Society]] | volume = 128 | issue = 8 | pages = 2504–2505 | date = Mar 2006 | pmid = 16492012 | doi = 10.1021/ja055650n | bibcode = 2006JAChS.128.2504Z }}</ref>

Xenon does not react with oxygen directly; the trioxide is formed by the hydrolysis of {{chem|XeF|6}}:<ref>{{cite book | vauthors = Holloway JH, Hope EG | title = Advances in Inorganic Chemistry Press | pages = 65 | date = 1998 | veditors = Sykes AG | publisher = Academic | isbn = 978-0-12-023646-6 | url = https://books.google.com/books?id=6iqXRtz6p3QC&pg=PA65 }}</ref>
: {{chem|XeF|6}} + 3 {{chem|H|2|O}} → {{chem|XeO|3}} + 6 HF

{{chem|XeO|3}} is weakly acidic, dissolving in alkali to form unstable ''xenate'' salts containing the {{chem|HXeO|4|−}} anion. These unstable salts easily [[disproportionation|disproportionate]] into xenon gas and [[perxenate]] salts, containing the {{chem|XeO|6|4−}} anion.<ref name="Henderson_2000">{{cite book | vauthors = Henderson W | title = Main group chemistry | location = Great Britain | pages = 152–153 | date = 2000 | publisher = [[Royal Society of Chemistry]] | isbn = 978-0-85404-617-1 | url = https://books.google.com/books?id=twdXz1jfVOsC&pg=PA152 }}</ref>

Barium perxenate, when treated with concentrated [[sulfuric acid]], yields gaseous xenon tetroxide:<ref name="Scott_1994" />
: {{chem|Ba|2|XeO|6}} + 2 {{chem|H|2|SO|4}} → 2 {{chem|BaSO|4}} + 2 {{chem|H|2|O}} + {{chem|XeO|4}}

To prevent decomposition, the xenon tetroxide thus formed is quickly cooled into a pale-yellow solid. It explodes above −35.9&nbsp;°C into xenon and oxygen gas, but is otherwise stable.

A number of xenon oxyfluorides are known, including {{chem|XeOF|2}}, [[xenon oxytetrafluoride|{{chem|XeOF|4}}]], {{chem|XeO|2|F|2}}, and {{chem|XeO|3|F|2}}. {{chem |XeOF|2}} is formed by reacting [[oxygen difluoride|{{chem|OF|2}}]] with xenon gas at low temperatures. It may also be obtained by partial hydrolysis of {{chem|XeF|4}}. It disproportionates at −20&nbsp;°C into {{chem|XeF|2}} and {{chem|XeO|2|F|2}}.<ref name="Mackay_2002">{{cite book | vauthors = Mackay KM, Mackay RA, Henderson W | title = Introduction to modern inorganic chemistry | pages = 497–501 | date = 2002 | edition = 6th | publisher = CRC Press | isbn = 978-0-7487-6420-4 | url = https://books.google.com/books?id=LpJPWKT3PNcC&pg=PA497 }}</ref> {{chem |XeOF|4}} is formed by the partial hydrolysis of {{chem |XeF|6}}...<ref>{{cite journal | vauthors = Smith DF | title = Xenon Oxyfluoride | journal = Science | volume = 140 | issue = 3569 | pages = 899–900 | date = May 1963 | pmid = 17810680 | doi = 10.1126/science.140.3569.899 | s2cid = 42752536 | bibcode = 1963Sci...140..899S }}</ref>
:{{chem |XeF|6}} + {{chem |H|2|O}} → {{chem |XeOF|4}} + 2 {{chem |H|F}}
...or the reaction of {{chem|XeF|6}} with sodium perxenate, {{chem |Na|4|XeO|6}}. The latter reaction also produces a small amount of {{chem|XeO|3|F|2}}.

{{chem |Xe|O|2|F|2}} is also formed by partial hydrolysis of {{chem |Xe|F|6}}.<ref>{{cite book | chapter = P Block Elements | title = Chemistry Textbook Part – 1 for Class XII | pages = 204 | date = 2007 | publisher = NCERT | isbn = 978-81-7450-648-1 | edition = October 2022 | url = https://ncert.nic.in/ncerts/l/lech107.pdf | language = English }}</ref>
:{{chem |Xe|F|6}} + 2 {{chem |H|2|O}} → {{chem |Xe|O|2|F|2}} + 4 {{chem |HF}}
{{chem|XeOF|4}} reacts with [[caesium fluoride|CsF]] to form the {{chem |XeOF|5|−}} anion,<ref name="Mackay_2002" /><ref>{{cite journal | vauthors = Christe KO, Dixon DA, Sanders JC, Schrobilgen GJ, Tsai SS, Wilson WW | title = On the Structure of the [XeOF<sub>5</sub>]<sup>−</sup> Anion and of Heptacoordinated Complex Fluorides Containing One or Two Highly Repulsive Ligands or Sterically Active Free Valence Electron Pairs | journal = [[inorganic Chemistry (journal) | inorg. Chem.]] | volume = 34 | issue = 7 | pages = 1868–1874 | year = 1995 | doi = 10.1021/ic00111a039 }}</ref> while XeOF<sub>3</sub> reacts with the alkali metal fluorides [[potassium fluoride|KF]], [[rubidium fluoride|RbF]] and CsF to form the {{chem|XeOF|4|−}} anion.<ref>{{cite journal | vauthors = Christe KO, Schack CJ, Pilipovich D | title = Chlorine trifluoride oxide. V. Complex formation with Lewis acids and bases | journal = [[inorganic Chemistry (journal) | inorg. Chem.]] | volume = 11 | issue = 9 | pages = 2205–2208 | year = 1972 | doi = 10.1021/ic50115a044 }}</ref>

=== Other compounds ===
Xenon can be directly bonded to a less electronegative element than fluorine or oxygen, particularly [[carbon]].<ref>{{cite book | vauthors = Holloway JH, Hope EG | title = Advances in Inorganic Chemistry | pages = 61–90 | year = 1998 | others = Contributor A. G. Sykes | publisher = Academic Press | isbn = 978-0-12-023646-6 | url = https://books.google.com/books?id=6iqXRtz6p3QC&pg=PA61 }}</ref> Electron-withdrawing groups, such as groups with fluorine substitution, are necessary to stabilize these compounds.<ref name="Henderson_2000" /> Numerous such compounds have been characterized, including:<ref name="Mackay_2002" /><ref>{{cite journal | vauthors = Frohn H, Theißen M | title = C<sub>6</sub>F<sub>5</sub>XeF, a versatile starting material in xenon–carbon chemistry | journal = Journal of Fluorine Chemistry | volume = 125 | issue = 6 | pages = 981–988 | year = 2004 | doi = 10.1016/j.jfluchem.2004.01.019 }}</ref>
* {{chem|C|6|F|5|–Xe|+|–N≡C–CH|3}}, where C<sub>6</sub>F<sub>5</sub> is the pentafluorophenyl group.
* {{chem|[C|6|F|5|]|2|Xe}}
* {{chem|C|6|F|5|–Xe–C≡N}}
* {{chem|C|6|F|5|–Xe–F}}
* {{chem|C|6|F|5|–Xe–Cl}}
* {{chem|C|2|F|5|–C≡C–Xe|+}}
* {{chem|[C|H|3|]|3|C–C≡C–Xe|+}}
* {{chem|C|6|F|5|–XeF|2|+}}
* {{chem|(C|6|F|5|Xe)|2|Cl|+}}

Other compounds containing xenon bonded to a less electronegative element include {{chem|F–Xe–N(SO|2|F)|2}} and {{chem|F–Xe–BF|2}}. The latter is synthesized from [[dioxygenyl]] tetrafluoroborate, {{chem|O|2|BF|4}}, at −100&nbsp;°C.<ref name="Mackay_2002" /><ref>{{cite journal | vauthors = Goetschel CT, Loos KR | title = Reaction of xenon with dioxygenyl tetrafluoroborate. Preparation of FXe–BF<sub>2</sub> | journal = Journal of the American Chemical Society | volume = 94 | issue = 9 | pages = 3018–3021 | date = 1972 | doi = 10.1021/ja00764a022 | bibcode = 1972JAChS..94.3018G }}</ref>

An unusual ion containing xenon is the [[tetraxenonogold(II)]] cation, {{chem|AuXe|4|2+}}, which contains Xe–Au bonds.<ref name="Li_2008">{{cite book | vauthors = Li WK, Zhou GD, Mak TC | title = Advanced Structural Inorganic Chemistry | pages = 678 | date = 2008 | veditors = Zhou GD, Mak TC | publisher = [[Oxford University Press]] | isbn = 978-0-19-921694-9 | url = https://books.google.com/books?id=2qAa5hp6KX4C&pg=PA678 }}</ref> This ion occurs in the compound {{chem|AuXe|4|(Sb|2|F|11|)|2}}, and is remarkable in having direct chemical bonds between two notoriously unreactive atoms, xenon and [[gold]], with xenon acting as a transition metal ligand. A similar mercury complex (HgXe)(Sb<sub>3</sub>F<sub>17</sub>) (formulated as [HgXe<sup>2+</sup>][Sb<sub>2</sub>F<sub>11</sub><sup>–</sup>][SbF<sub>6</sub><sup>–</sup>]) is also known.<ref>{{Cite journal | vauthors = Hwang IC, Seidel S, Seppelt K | title = Gold( I ) and Mercury( II ) Xenon Complexes | journal = Angewandte Chemie International Edition | volume = 42 | issue = 36 | pages = 4392–4395 | date = September 22, 2003 | pmid = 14502720 | doi = 10.1002/anie.200351208 | bibcode = 2003ACIE...42.4392H | url = https://onlinelibrary.wiley.com/doi/10.1002/anie.200351208 | language = en | issn = 1433-7851 | url-access = subscription }}</ref>

The compound {{chem|Xe|2|Sb|2|F|11}} contains a Xe–Xe bond, the longest element-element bond known (308.71&nbsp;pm = 3.0871&nbsp;[[Angstrom|Å]]).<ref>{{cite book | vauthors = Li WK, Zhou GD, Mak TC | title = Advanced Structural Inorganic Chemistry | pages = [https://archive.org/details/advancedstructur00liwa/page/n696 674] | date = 2008 | url = https://archive.org/details/advancedstructur00liwa | url-access = limited | publisher = Oxford University Press | isbn = 978-0-19-921694-9 }}</ref>

In 1995, M. Räsänen and co-workers, scientists at the [[University of Helsinki]] in [[Finland]], announced the preparation of xenon dihydride (HXeH), and later xenon hydride-hydroxide (HXeOH), hydroxenoacetylene (HXeCCH), and other Xe-containing molecules.<ref>{{cite journal | vauthors = Gerber RB | title = Formation of novel rare-gas molecules in low-temperature matrices | journal = Annual Review of Physical Chemistry | volume = 55 | issue = 1 | pages = 55–78 | date = 2004 | pmid = 15117247 | doi = 10.1146/annurev.physchem.55.091602.094420 | bibcode = 2004ARPC...55...55G }}</ref> In 2008, Khriachtchev ''et al.'' reported the preparation of HXeOXeH by the [[photolysis]] of water within a [[cryogenic]] xenon matrix.<ref>{{cite journal | vauthors = Khriachtchev L, Isokoski K, Cohen A, Räsänen M, Gerber RB | title = A Small Neutral Molecule with Two Noble-Gas Atoms: HXeOXeH | journal = Journal of the American Chemical Society | volume = 130 | issue = 19 | pages = 6114–6118 | date = May 2008 | pmid = 18407641 | doi = 10.1021/ja077835v | bibcode = 2008JAChS.130.6114K }}</ref> [[Deuterium|Deuterated]] molecules, HXeOD and DXeOH, have also been produced.<ref>{{cite journal | vauthors = Pettersson M, Khriachtchev L, Lundell J, Räsänen M | title = A Chemical Compound Formed from Water and Xenon: HXeOH | journal = Journal of the American Chemical Society | volume = 121 | issue = 50 | pages = 11904–11905 | date = 1999 | doi = 10.1021/ja9932784 | bibcode = 1999JAChS.12111904P }}</ref>

=== Clathrates and excimers ===
{{See also|Excimer laser}}
In addition to compounds where xenon forms a [[chemical bond]], xenon can form [[clathrate]]s—substances where xenon atoms or pairs are trapped by the [[Crystal structure|crystalline lattice]] of another compound. One example is [[xenon hydrate]] (Xe·{{frac|5|3|4}}H<sub>2</sub>O), where xenon atoms occupy vacancies in a lattice of water molecules.<ref>{{cite journal | vauthors = Pauling L | title = A molecular theory of general anesthesia | url = https://archive.org/details/sim_science_1961-07-07_134_3471/page/14 | journal = Science | volume = 134 | issue = 3471 | pages = 15–21 | date = Jul 1961 | pmid = 13733483 | doi = 10.1126/science.134.3471.15 | bibcode = 1961Sci...134...15P }} Reprinted as {{cite book | title = Linus Pauling: Selected Scientific Papers | volume = 2 | pages = 1328–1334 | year = 2001 | veditors = Pauling L, Linus, Kamb B | place = River Edge, NJ | publisher = World Scientific | isbn = 978-981-02-2940-5 | url = https://books.google.com/books?id=2QduA19d_X8C&pg=PA1329 }}</ref> This clathrate has a melting point of 24&nbsp;°C.<ref name="Henderson_2000a">{{cite book | vauthors = Henderson W | title = Main group chemistry | location = Great Britain | pages = 148 | date = 2000 | publisher = Royal Society of Chemistry | isbn = 978-0-85404-617-1 | url = https://books.google.com/books?id=twdXz1jfVOsC&pg=PA148 }}</ref> The [[deuterate]]d version of this hydrate has also been produced.<ref>{{cite journal | vauthors = Ikeda T, Mae S, Yamamuro O, Matsuo T, Ikeda S, Ibberson RM | title = Distortion of Host Lattice in Clathrate Hydrate as a Function of Guest Molecule and Temperature | journal = Journal of Physical Chemistry A | volume = 104 | issue = 46 | pages = 10623–10630 | date = November 23, 2000 | doi = 10.1021/jp001313j | bibcode = 2000JPCA..10410623I }}</ref> Another example is xenon [[hydride]] (Xe(H<sub>2</sub>)<sub>8</sub>), in which xenon pairs ([[Dimer (chemistry)|dimers]]) are trapped inside [[solid hydrogen]].<ref name="Kleppe_2014">{{cite journal | vauthors = Kleppe AK, Amboage M, Jephcoat AP | title = New high-pressure van der Waals compound Kr(H<sub>2</sub>)<sub>4</sub> discovered in the krypton-hydrogen binary system | journal = Scientific Reports | volume = 4 | article-number = 4989 | year = 2014 | doi = 10.1038/srep04989 | bibcode = 2014NatSR...4.4989K | doi-access = free }}</ref> Such [[clathrate hydrate]]s can occur naturally under conditions of high pressure, such as in [[Lake Vostok]] underneath the [[Antarctica|Antarctic]] ice sheet.<ref>{{cite journal | vauthors = McKay CP, Hand KP, Doran PT, Andersen DT, Priscu JC | title = Clathrate formation and the fate of noble and biologically useful gases in Lake Vostok, Antarctica | journal = Geophysical Research Letters | volume = 30 | issue = 13 | pages = 35 | date = 2003 | article-number = 2003GL017490 | doi = 10.1029/2003GL017490 | bibcode = 2003GeoRL..30.1702M | s2cid = 20136021 }}</ref> Clathrate formation can be used to fractionally distill xenon, argon and krypton.<ref>{{cite journal | vauthors = Barrer RM, Stuart WI | title = Non-Stoichiometric Clathrate of Water | journal = Proceedings of the Royal Society of London | volume = 243 | issue = 1233 | pages = 172–189 | year = 1957 | doi = 10.1098/rspa.1957.0213 | s2cid = 97577041 | bibcode = 1957RSPSA.243..172B }}</ref>

Xenon can also form [[endohedral fullerene]] compounds, where a xenon atom is trapped inside a [[fullerene]] molecule. The xenon atom trapped in the fullerene can be observed by <sup>129</sup>Xe [[nuclear magnetic resonance]] (NMR) spectroscopy. Through the sensitive [[chemical shift]] of the xenon atom to its environment, chemical reactions on the fullerene molecule can be analyzed. These observations are not without caveat, however, because the xenon atom has an electronic influence on the reactivity of the fullerene.<ref>{{cite journal | vauthors = Frunzi M, Cross RJ, Saunders M | title = Effect of Xenon on Fullerene Reactions | journal = Journal of the American Chemical Society | volume = 129 | issue = 43 | pages = 13343–13346 | date = 2007 | pmid = 17924634 | doi = 10.1021/ja075568n | bibcode = 2007JAChS.12913343F | url = https://figshare.com/articles/journal_contribution/2977702 | url-access = subscription }}</ref>

When xenon atoms are in the [[stationary state|ground energy state]], they repel each other and will not form a bond. When xenon atoms becomes energized, however, they can form an [[excimer]] (excited dimer) until the electrons return to the [[ground state]]. This entity is formed because the xenon atom tends to complete the outermost [[Electron shell|electronic shell]] by adding an electron from a neighboring xenon atom. The typical lifetime of a xenon excimer is 1–5&nbsp;nanoseconds, and the decay releases [[photon]]s with [[wavelength]]s of about 150 and 173&nbsp;[[Nanometre|nm]].<ref>{{cite book | vauthors = Silfvast WT | title = Laser Fundamentals | year = 2004 | publisher = [[Cambridge University Press]] | isbn = 978-0-521-83345-5 | url = https://books.google.com/books?id=x3VB2iwSaxsC&pg=RA1-PA152 }}</ref><ref>{{cite book | vauthors = Webster JG | title = The Measurement, Instrumentation, and Sensors Handbook | date = 1998 | publisher = Springer | isbn = 978-3-540-64830-7 | url = https://books.google.com/books?id=b7UuZzf9ivIC&pg=PT2427 }}</ref> Xenon can also form excimers with other elements, such as the [[halogen]]s [[fluorine]], [[chlorine]], and [[bromine]].<ref name=Brau1979>{{cite book | vauthors = Brau CA |author-link1=:d:Q79275751 |chapter=Rare Gas Halogen Excimers | veditors = Rhodes CK | title = Excimer Lasers |series=Topics in Applied Physics |volume=30 |date=1979 |publisher=Springer-Verlag |location=New York |isbn=978-0-387-09017-7}}</ref><ref>{{cite book | vauthors = McGhee C, Taylor HR, Gartry DS, Trokel SL | title = Excimer Lasers in Ophthalmology | date = 1997 | publisher = Informa Health Care | isbn = 978-1-85317-253-3 |url=https://archive.org/details/excimerlasersino0000unse/page/4/mode/2up?q=XeF}}</ref> The diatomic molecule XeF, present in xenon fluoride excimer lasers, has a ground state that is bound, but only very weakly, with an Xe–F [[bond dissociation energy]] of ~3 kcal·mol<sup>−1</sup>.<ref>{{cite journal | vauthors = Ovchinnikov M, Masyagutova G, Khursan S | title = High level ab initio thermochemistry of XeF radical | journal = Journal of Fluorine Chemistry | volume = 209 | pages = 1–5 | date = May 2018 | doi = 10.1016/j.jfluchem.2018.02.003 | bibcode = 2018JFluC.209....1O }}</ref><ref>{{cite journal | vauthors = Tellinghuisen PC, Tellinghuisen J | title = Precise Characterization of the B (1/2) and C (3/2) States of XeF from a Deperturbation Analysis of the B → X Spectrum of <sup>136</sup>XeF | journal = The Journal of Physical Chemistry A | volume = 106 | issue = 36 | pages = 8317–8322 | date = 1 September 2002 | doi = 10.1021/jp0156221 }}</ref>

== Applications ==
Although xenon is rare and relatively expensive to extract from the [[atmosphere of Earth|Earth's atmosphere]], it has a number of applications.

=== Illumination and optics ===

==== Gas-discharge lamps ====
[[File:Xenon short arc 1.jpg|thumb|Xenon short-arc lamp|alt=Elongated glass sphere with two metal rod electrodes inside, facing each other. One electrode is blunt and another is sharpened.]]
[[File:STS-135 Atlantis rollout 1.jpg|thumb|Space Shuttle ''[[Space Shuttle Atlantis|Atlantis]]'' bathed in xenon lights]]
[[File:Xenon discharge tube.jpg|thumb|Xenon gas discharge tube]]
Xenon is used in light-emitting devices called xenon flash lamps, used in [[Flash (photography)|photographic flashes]] and stroboscopic lamps;<ref name="Burke_2003">{{cite book | vauthors = Burke J | title = Twin Tracks: The Unexpected Origins of the Modern World | pages = [https://archive.org/details/twintracks00jame/page/33 33] | date = 2003 | publisher = Oxford University Press | isbn = 978-0-7432-2619-6 | url = https://archive.org/details/twintracks00jame/page/33 }}</ref> to excite the [[active laser medium|active medium]] in [[laser]]s which then generate [[coherent light]];<ref>{{cite web | vauthors = Staff | title = Xenon Applications | year = 2007 | url = http://www.praxair.com/praxair.nsf/1928438066cae92d85256a63004b880d/32f3a328e11bb600052565660052c139?OpenDocument | publisher = Praxair Technology | access-date = October 4, 2007 | archive-date = March 22, 2013 | archive-url = https://web.archive.org/web/20130322123535/http://www.praxair.com/praxair.nsf/1928438066cae92d85256a63004b880d/32f3a328e11bb600052565660052c139?OpenDocument | url-status = dead }}</ref> and, occasionally, in [[Bactericide|bactericidal]] lamps.<ref>{{cite journal | vauthors = Baltás E, Csoma Z, Bodai L, Ignácz F, Dobozy A, Kemény L | title = A xenon-iodine electric discharge bactericidal lamp | journal = [[Technical Physics Letters]] | volume = 29 | issue = 10 | pages = 871–872 | year = 2003 | doi = 10.1134/1.1623874 | s2cid = 122651818 | bibcode = 2003TePhL..29..871S }}</ref> The first solid-state laser, invented in 1960, was pumped by a xenon flash lamp,<ref name="Toyserkani_2004">{{cite book | vauthors = Toyserkani E, Khajepour A, Corbin S | title = Laser Cladding | pages = 48 | date = 2004 | publisher = CRC Press | isbn = 978-0-8493-2172-6 | url = https://books.google.com/books?id=zfvbyCHzVqMC&pg=PA48 }}</ref> and lasers used to power [[inertial confinement fusion]] are also pumped by xenon flash lamps.<ref>{{cite journal | vauthors = Skeldon MD, Saager R, Okishev A, Seka W | title = Thermal distortions in laser-diode- and flash-lamp-pumped Nd:YLF laser rods | journal = LLE Review | volume = 71 | pages = 137–144 | year = 1997 | url = http://www.lle.rochester.edu/pub/review/v71/6_thermal.pdf | access-date = February 4, 2007 | archive-url = https://web.archive.org/web/20031016171340/http://www.lle.rochester.edu/pub/review/v71/6_thermal.pdf | archive-date = October 16, 2003 }}</ref>

Continuous, short-arc, high pressure [[xenon arc lamp]]s have a [[color temperature]] closely approximating noon sunlight and are used in [[Solar Simulator|solar simulators]]. That is, the [[chromaticity]] of these lamps closely approximates a heated [[black body]] radiator at the temperature of the Sun. First introduced in the 1940s, these lamps replaced the shorter-lived [[carbon arc lamp]]s in movie projectors.<ref name="Mellor_2000">{{cite book | vauthors = Mellor D | title = Sound Person's Guide to Video | pages = [https://archive.org/details/soundpersonsguid0000mell/page/186 186] | year = 2000 | publisher = [[Focal Press]] | isbn = 978-0-240-51595-3 | url = https://archive.org/details/soundpersonsguid0000mell | url-access = registration }}</ref> They are also employed in typical [[35mm movie film|35mm]], [[IMAX]], and [[digital projectors|digital]] [[Movie projector|film projection]] systems. They are an excellent source of short wavelength [[ultraviolet]] radiation and have intense emissions in the near [[infrared]] used in some [[night vision]] systems. Xenon is used as a starter gas in [[Metal-halide lamp|metal halide lamps]] for [[HID Headlight|automotive HID headlights]], and high-end [[tactical light|"tactical" flashlights]].

The individual cells in a [[plasma display]] contain a mixture of xenon and neon ionized with [[electrode]]s. The interaction of this plasma with the electrodes generates ultraviolet [[photon]]s, which then excite the [[phosphor]] coating on the front of the display.<ref>{{cite web | vauthors = Anonymous | title = The plasma behind the plasma TV screen | url = http://www.plasmatvscience.org/theinnerworkings.html | publisher = Plasma TV Science | access-date = October 14, 2007 | url-status = dead | archive-url = https://web.archive.org/web/20071015160452/http://plasmatvscience.org/theinnerworkings.html | archive-date = October 15, 2007 }}</ref><ref>{{cite news | vauthors = Marin R | title = Plasma TV: That New Object Of Desire | date = March 21, 2001 | newspaper = [[The New York Times]] | url = https://www.nytimes.com/2001/03/25/style/plasma-tv-that-new-object-of-desire.html?sec=&spon= | access-date = April 3, 2009 }}</ref>

Xenon is used as a "starter gas" in [[Sodium vapor lamp|high pressure sodium lamps]]. It has the lowest [[thermal conductivity]] and lowest [[ionization potential]] of all the non-radioactive noble gases. As a noble gas, it does not interfere with the chemical reactions occurring in the operating lamp. The low thermal conductivity minimizes thermal losses in the lamp while in the operating state, and the low ionization potential causes the [[breakdown voltage]] of the gas to be relatively low in the cold state, which allows the lamp to be more easily started.<ref>{{cite book | vauthors = Waymouth J | title = Electric Discharge Lamps | location = Cambridge, MA | date = 1971 | publisher = [[MIT Press]] | isbn = 978-0-262-23048-3 | url = https://archive.org/details/electricdischarg00waym }}</ref>

==== Lasers ====
In 1962, a group of researchers at [[Bell Labs|Bell Laboratories]] discovered laser action in xenon,<ref>{{cite journal | vauthors = Patel CK, Bennett Jr WR, Faust WL, McFarlane RA | title = Infrared spectroscopy using stimulated emission techniques | journal = Physical Review Letters | volume = 9 | issue = 3 | pages = 102–104 | date = August 1, 1962 | doi = 10.1103/PhysRevLett.9.102 | bibcode = 1962PhRvL...9..102P }}</ref> and later found that the laser gain was improved by adding [[helium]] to the lasing medium.<ref>{{cite journal | vauthors = Patel CK, Faust WL, McFarlane RA | title = High gain gaseous (Xe–He) optical masers | journal = Applied Physics Letters | volume = 1 | issue = 4 | pages = 84–85 | date = December 1, 1962 | doi = 10.1063/1.1753707 | bibcode = 1962ApPhL...1...84P | doi-access = free }}</ref><ref>{{cite journal | vauthors = Bennett Jr WR | title = Gaseous optical masers | journal = Applied Optics | volume = 1 | issue = S1 | pages = 24–61 | year = 1962 | doi = 10.1364/AO.1.000024 | bibcode = 1962ApOpt...1S..24B }}</ref> The first [[excimer laser]] used a xenon [[Dimer (chemistry)|dimer]] (Xe<sub>2</sub>) energized by a beam of electrons to produce [[stimulated emission]] at an [[ultraviolet]] wavelength of 176 [[nanometre|nm]].<ref name="Basov_1971">{{cite journal | vauthors = Basov NG, Danilychev VA, Popov YM | title = Stimulated Emission in the Vacuum Ultraviolet Region | journal = Soviet Journal of Quantum Electronics | volume = 1 | issue = 1 | pages = 18–22 | year = 1971 | doi = 10.1070/QE1971v001n01ABEH003011 | bibcode = 1971QuEle...1...18B }}</ref>
Xenon chloride and xenon fluoride have also been used in excimer (or, more accurately, exciplex) lasers.<ref>{{cite web | title = Laser Output | url = http://www.safetyoffice.uwaterloo.ca/hse/laser/documents/laser_types.html | publisher = University of Waterloo | access-date = October 7, 2007 | archive-date = July 6, 2011 | archive-url = https://web.archive.org/web/20110706212050/http://www.safetyoffice.uwaterloo.ca/hse/laser/documents/laser_types.html | url-status = dead }}</ref>

=== Medical ===
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| DailyMedID        = Xenon
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| ATC_suffix        = CX12
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| legal_UK_comment  = 
| legal_US          = Rx-only
| legal_US_comment  = <ref>{{cite web | title = Xenon, Xe-133- xenon gas | date = October 16, 2024 | website = DailyMed | url = https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5eb971be-8808-4aeb-9898-0d22d5dffe04 | access-date = December 24, 2024 }}</ref><ref>{{cite web | title = Xenon- xenon xe-133 gas | date = November 28, 2022 | website = DailyMed | url = https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=35bdc182-2a41-41d2-8fe7-aa0c140d4425 | access-date = December 24, 2024 }}</ref><ref>{{cite web | title = Xenoview- xenon xe 129 hyperpolarized gas | date = December 30, 2022 | website = DailyMed | url = https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=70e33fe3-c722-439b-b3db-c2a22f229c8a | access-date = December 24, 2024 }}</ref>
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| StdInChI=1S/Xe
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==== Anesthesia ====
Xenon has been used as a [[general anesthetic]], but it is more expensive than conventional anesthetics.<ref>{{cite journal | vauthors = Neice AE, Zornow MH | title = Xenon anaesthesia for all, or only a select few? | journal = Anaesthesia | volume = 71 | issue = 11 | pages = 1267–1272 | date = Nov 2016 | pmid = 27530275 | doi = 10.1111/anae.13569 | doi-access = free }}</ref>

Xenon interacts with many different receptors and ion channels, and like many theoretically multi-modal inhalation anesthetics, these interactions are likely complementary. Xenon is a high-affinity glycine-site [[NMDA receptor antagonist]].<ref name="Banks_2010">{{cite journal | vauthors = Banks P, Franks NP, Dickinson R | title = Competitive inhibition at the glycine site of the N-methyl-D-aspartate receptor mediates xenon neuroprotection against hypoxia-ischemia | journal = Anesthesiology | volume = 112 | issue = 3 | pages = 614–622 | date = Mar 2010 | pmid = 20124979 | doi = 10.1097/ALN.0b013e3181cea398 | doi-access = free }}</ref> However, xenon is different from certain other NMDA receptor antagonists in that it is not [[neurotoxicity|neurotoxic]] and it inhibits the neurotoxicity of [[ketamine]] and [[nitrous oxide]] (N<sub>2</sub>O), while actually producing [[neuroprotection|neuroprotective effects]].<ref>{{cite journal | vauthors = Ma D, Wilhelm S, Maze M, Franks NP | title = Neuroprotective and neurotoxic properties of the 'inert' gas, xenon | journal = British Journal of Anaesthesia | volume = 89 | issue = 5 | pages = 739–746 | date = Nov 2002 | pmid = 12393773 | doi = 10.1093/bja/89.5.739 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Nagata A, Nakao Si S, Nishizawa N, Masuzawa M, Inada T, Murao K, Miyamoto E, Shingu K | title = Xenon inhibits but N<sub>2</sub>O enhances ketamine-induced c-Fos expression in the rat posterior cingulate and retrosplenial cortices | journal = Anesthesia & Analgesia | volume = 92 | issue = 2 | pages = 362–368 | date = Feb 2001 | pmid = 11159233 | doi = 10.1213/00000539-200102000-00016 | s2cid = 15167421 | doi-access = free }}</ref> Unlike ketamine and nitrous oxide, xenon does not stimulate a dopamine efflux in the [[nucleus accumbens]].<ref>{{cite journal | vauthors = Sakamoto S, Nakao S, Masuzawa M, Inada T, Maze M, Franks NP, Shingu K | title = The differential effects of nitrous oxide and xenon on extracellular dopamine levels in the rat nucleus accumbens: a microdialysis study | journal = [[Anesthesia & Analgesia]] | volume = 103 | issue = 6 | pages = 1459–1463 | date = Dec 2006 | pmid = 17122223 | doi = 10.1213/01.ane.0000247792.03959.f1 | s2cid = 1882085 }}</ref>

Like nitrous oxide and [[cyclopropane]], xenon activates the two-pore domain potassium channel [[KCNK2|TREK-1]]. A related channel [[KCNK9|TASK-3]] also implicated in the actions of inhalation anesthetics is insensitive to xenon.<ref>{{cite journal | vauthors = Gruss M, Bushell TJ, Bright DP, Lieb WR, Mathie A, Franks NP | title = Two-pore-domain K<sup>+</sup> channels are a novel target for the anesthetic gases xenon, nitrous oxide, and cyclopropane | journal = Molecular Pharmacology | volume = 65 | issue = 2 | pages = 443–452 | date = Feb 2004 | pmid = 14742687 | doi = 10.1124/mol.65.2.443 | s2cid = 7762447 }}</ref> Xenon inhibits nicotinic acetylcholine [[Alpha-4 beta-2 nicotinic receptor|α4β2]] receptors which contribute to spinally mediated analgesia.<ref>{{cite journal | vauthors = Yamakura T, Harris RA | title = Effects of gaseous anesthetics nitrous oxide and xenon on ligand-gated ion channels. Comparison with isoflurane and ethanol | journal = Anesthesiology | volume = 93 | issue = 4 | pages = 1095–1101 | date = Oct 2000 | pmid = 11020766 | doi = 10.1097/00000542-200010000-00034 | s2cid = 4684919 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Rashid MH, Furue H, Yoshimura M, Ueda H | title = Tonic inhibitory role of α4β2 subtype of nicotinic acetylcholine receptors on nociceptive transmission in the spinal cord in mice | journal = Pain | volume = 125 | issue = 1–2 | pages = 125–135 | date = Nov 2006 | pmid = 16781069 | doi = 10.1016/j.pain.2006.05.011 | s2cid = 53151557 }}</ref> Xenon is an effective inhibitor of [[Plasma membrane Ca2+ ATPase|plasma membrane Ca<sup>2+</sup> ATPase]]. Xenon inhibits Ca<sup>2+</sup> ATPase by binding to a hydrophobic pore within the enzyme and preventing the enzyme from assuming active conformations.<ref>{{cite journal | vauthors = Lopez MM, Kosk-Kosicka D | title = How Do Volatile Anesthetics Inhibit Ca<sup>2+</sup>–ATPases? | journal = [[The Journal of Biological Chemistry]] | volume = 270 | issue = 47 | pages = 28239–28245 | date = Nov 1995 | pmid = 7499320 | doi = 10.1074/jbc.270.47.28239 | doi-access = free }}</ref>

Xenon is a competitive inhibitor of the [[serotonin]] [[5-HT3 receptor|5-HT<sub>3</sub> receptor]]. While neither anesthetic nor antinociceptive, this reduces anesthesia-emergent nausea and vomiting.<ref>{{cite journal | vauthors = Suzuki T, Koyama H, Sugimoto M, Uchida I, Mashimo T | title = The diverse actions of volatile and gaseous anesthetics on human-cloned 5-hydroxytryptamine<sup>3</sup> receptors expressed in ''Xenopus'' oocytes | journal = Anesthesiology | volume = 96 | issue = 3 | pages = 699–704 | date = Mar 2002 | pmid = 11873047 | doi = 10.1097/00000542-200203000-00028 | s2cid = 6705116 | doi-access = free }}</ref>

Xenon has a [[minimum alveolar concentration]] (MAC) of 72% at age 40, making it 44% more potent than N<sub>2</sub>O as an anesthetic.<ref>{{cite journal | vauthors = Nickalls R, Mapleson W | title = Age-related iso-MAC charts for isoflurane, sevoflurane and desflurane in man | journal = British Journal of Anaesthesia | volume = 91 | issue = 2 | pages = 170–174 | date = August 2003 | pmid = 12878613 | doi = 10.1093/bja/aeg132 | doi-access = free }}</ref> Thus, it can be used with oxygen in concentrations that have a lower risk of [[Hypoxia (medical)|hypoxia]]. Unlike nitrous oxide, xenon is not a [[greenhouse gas]] and is viewed as [[environmentally friendly]].<ref name="Goto_2003">{{Cite journal | vauthors = Goto T, Y N, S M | title = Will xenon be a stranger or a friend?: the cost, benefit, and future of xenon anesthesia | journal = Anesthesiology | volume = 98 | issue = 1 | pages = 1–2 | date = Jan 2003 | pmid = 12502969 | doi = 10.1097/00000542-200301000-00002 | s2cid = 19119058 | doi-access = free }}</ref> Though recycled in modern systems, xenon vented to the atmosphere is only returning to its original source, without environmental impact.

==== Neuroprotectant ====
Xenon induces robust [[cardioprotection]] and [[neuroprotection]] through a variety of mechanisms. Through its influence on Ca<sup>2+</sup>, K<sup>+</sup>, [[ATP-sensitive potassium channel|KATP]]\HIF, and NMDA antagonism, xenon is neuroprotective when administered before, during and after [[Ischemia|ischemic]] insults.<ref>{{cite journal | vauthors = Schmidt M, Marx T, Glöggl E, Reinelt H, Schirmer U | title = Xenon Attenuates Cerebral Damage after Ischemia in Pigs | journal = Anesthesiology | volume = 102 | issue = 5 | pages = 929–936 | date = May 2005 | pmid = 15851879 | doi = 10.1097/00000542-200505000-00011 | s2cid = 25266308 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Dingley J, Tooley J, Porter H, Thoresen M | title = Xenon Provides Short-Term Neuroprotection in Neonatal Rats When Administered After Hypoxia-Ischemia | journal = Stroke | volume = 37 | issue = 2 | pages = 501–506 | date = Feb 2006 | pmid = 16373643 | doi = 10.1161/01.STR.0000198867.31134.ac | url = http://www.reanimatology.com/rmt/article/view/1340 | doi-access = free }}</ref> Xenon is a high affinity antagonist at the NMDA receptor glycine site.<ref name="Banks_2010" /> Xenon is cardioprotective in ischemia-reperfusion conditions by inducing [[Pharmacology|pharmacologic]] non-ischemic preconditioning. Xenon is cardioprotective by activating PKC-epsilon and downstream p38-MAPK.<ref>{{cite journal | vauthors = Weber NC, Toma O, Wolter JI, Obal D, Müllenheim J, Preckel B, Schlack W | title = The noble gas xenon induces pharmacological preconditioning in the rat heart in vivo via induction of PKC-epsilon and p38 MAPK | journal = Br J Pharmacol | volume = 144 | issue = 1 | pages = 123–132 | date = Jan 2005 | pmid = 15644876 | pmc = 1575984 | doi = 10.1038/sj.bjp.0706063 }}</ref> Xenon mimics neuronal ischemic preconditioning by activating ATP sensitive potassium channels.<ref>{{cite journal | vauthors = Bantel C, Maze M, Trapp S | title = Neuronal preconditioning by inhalational anesthetics: evidence for the role of plasmalemmal adenosine triphosphate-sensitive potassium channels | journal = Anesthesiology | volume = 110 | issue = 5 | pages = 986–995 | date = May 2009 | pmid = 19352153 | pmc = 2930813 | doi = 10.1097/ALN.0b013e31819dadc7 }}</ref> Xenon allosterically reduces ATP mediated channel activation inhibition independently of the sulfonylurea receptor1 subunit, increasing KATP open-channel time and frequency.<ref>{{cite journal | vauthors = Bantel C, Maze M, Trapp S | title = Noble gas xenon is a novel adenosine triphosphate-sensitive potassium channel opener | journal = Anesthesiology | volume = 112 | issue = 3 | pages = 623–630 | date = Mar 2010 | pmid = 20179498 | pmc = 2935677 | doi = 10.1097/ALN.0b013e3181cf894a }}</ref>

==== Sports doping and mountaineering ====
{{Anchor|Erythropoietin}}
Inhaling a xenon/oxygen mixture activates production of the [[transcription factor]] [[HIF1A|HIF-1-alpha]], which may lead to increased production of [[erythropoietin]]. The latter hormone is known to increase [[red blood cell]] production and athletic performance. Reportedly, doping with xenon inhalation has been used in Russia since 2004 and perhaps earlier.<ref>{{cite news | title = Breathe it in | date = February 8, 2014 | url = https://www.economist.com/news/science-and-technology/21595890-obscure-gas-improves-athletes-performance-breathe-it | newspaper = [[The Economist]] }}</ref> On August 31, 2014, the [[World Anti Doping Agency]] (WADA) added xenon (and [[argon]]) to the list of prohibited substances and methods, although no reliable doping tests for these gases have yet been developed.<ref>{{cite news | title = WADA amends Section S.2.1 of 2014 Prohibited List | date = August 31, 2014 | url = https://www.wada-ama.org/en/media/2014-05/wada-amends-section-s21-of-2014-prohibited-list | access-date = September 1, 2014 | archive-date = September 7, 2014 | archive-url = https://web.archive.org/web/20140907095626/https://www.wada-ama.org/en/media/2014-05/wada-amends-section-s21-of-2014-prohibited-list | url-status = dead }}</ref> In addition, effects of xenon on erythropoietin production in humans have not been demonstrated, so far.<ref>{{cite journal | vauthors = Jelkmann W | title = Xenon Misuse in Sports | journal = Deutsche Zeitschrift für Sportmedizin | volume = 2014 | issue = 10 | pages = 267–271 | year = 2014 | doi = 10.5960/dzsm.2014.143 | s2cid = 55832101 | publisher = Deutsche Zeitschrift für Sportmedizin/German Journal of Sports Medicine | doi-access = free }}</ref>

In 2025, four UK mountaineers, including [[Alistair Carns]], climbed [[Mount Everest]] in an expedition lasting only one week, claiming their inhalation of xenon gas to stimulate erythropoietin production had obviated the usual several weeks' [[altitude acclimatisation]]. The [[International Climbing and Mountaineering Federation]] (UIAA) criticised the decision, citing that there is no evidence that the inhalation of xenon improves performance in high elevation environments. Furthermore, the UIAA warned that as an anesthetic, xenon gas could result in impaired brain function, respiratory compromise, and death if used in an unmonitored setting.<ref>{{Cite web | vauthors = Woodyatt A | title = They want to climb Everest in a week using an anesthetic gas. Critics warn it's dangerous | date = 2025-05-13 | url = https://www.cnn.com/2025/05/13/travel/climb-everest-one-week-xenon-intl | access-date = 2025-05-15 | website = CNN | language = en }}</ref><ref>{{Cite web | title = Can Mount Everest really be climbed in a week? | date = 2025-04-29 | url = https://www.bbc.com/future/article/20250428-can-mount-everest-really-be-climbed-in-a-week | access-date = 2025-05-15 | website = www.bbc.com | language = en-GB }}</ref><ref>{{Cite news | vauthors = Wolfe J, Sharma B | title = They Inhaled a Gas and Scaled Everest in Days. Is It the Future of Mountaineering? | date = 2025-05-27 | url = https://www.nytimes.com/2025/05/27/world/europe/mount-everest-xenon-gas-nepal-uk-climbers.html | access-date = 2025-05-27 | work = The New York Times | language = en-US }}</ref>

==== Imaging ====
{{main|Xenon gas MRI}}
[[gamma ray|Gamma]] emission from the [[radioisotope]] <sup>133</sup>Xe of xenon can be used to image the heart, lungs, and brain, for example, by means of [[single photon emission computed tomography]]. <sup>133</sup>Xe has also been used to measure [[blood flow]].<ref>{{cite book | vauthors = Van Der Wall E | title = What's New in Cardiac Imaging?: SPECT, PET, and MRI | date = 1992 | publisher = Springer | isbn = 978-0-7923-1615-2 | url = https://books.google.com/books?id=PypZMUhqnK8C&pg=PA41 }}</ref><ref>{{cite journal | vauthors = Frank J | title = Introduction to imaging: The chest | journal = Student BMJ | volume = 12 | pages = 1–44 | year = 1999 | url = http://student.bmj.com/issues/04/01/education/8.php | access-date = June 4, 2008 }}</ref><ref>{{cite web | vauthors = Chandak PK | title = Brain SPECT: Xenon-133 | date = July 20, 1995 | url = http://brighamrad.harvard.edu/education/online/BrainSPECT/Theory/Xenon133.html | publisher = Brigham RAD | access-date = June 4, 2008 | url-status = dead | archive-url = https://web.archive.org/web/20120104015834/http://brighamrad.harvard.edu/education/online/BrainSPECT/Theory/Xenon133.html | archive-date = January 4, 2012 }}</ref>

Xenon, particularly hyperpolarized <sup>129</sup>Xe, is a useful [[contrast agent]] for [[MRI|magnetic resonance imaging]] (MRI). In the gas phase, it can image cavities in a porous sample, alveoli in lungs, or the flow of gases within the lungs.<ref>{{cite journal | vauthors = Albert MS, Balamore D | title = Development of hyperpolarized noble gas MRI | journal = Nuclear Instruments and Methods in Physics Research A | volume = 402 | issue = 2–3 | pages = 441–453 | year = 1998 | pmid = 11543065 | doi = 10.1016/S0168-9002(97)00888-7 | bibcode = 1998NIMPA.402..441A }}</ref><ref>{{cite magazine | vauthors = Irion R | title = Head Full of Xenon? | date = March 23, 1999 | magazine = Science News | url = http://sciencenow.sciencemag.org/cgi/content/full/1999/323/3 | access-date = October 8, 2007 | archive-url = https://web.archive.org/web/20040117194538/http://sciencenow.sciencemag.org/cgi/content/full/1999/323/3 | archive-date = January 17, 2004 }}</ref> Because xenon is [[soluble]] both in water and in hydrophobic solvents, it can image various soft living tissues.<ref>{{cite journal | vauthors = Wolber J, Rowland IJ, Leach MO, Bifone A | title = Intravascular delivery of hyperpolarized 129Xenon for in vivo MRI | journal = Applied Magnetic Resonance | volume = 15 | issue = 3–4 | pages = 343–352 | date = 1998 | doi = 10.1007/BF03162020 | s2cid = 100913538 }}</ref><ref>{{cite journal | vauthors = Driehuys B, Möller H, Cleveland Z, Pollaro J, Hedlund L | title = Pulmonary perfusion and xenon gas exchange in rats: MR imaging with intravenous injection of hyperpolarized 129Xe | journal = Radiology | volume = 252 | issue = 2 | pages = 386–393 | date = 2009 | pmid = 19703880 | pmc = 2753782 | doi = 10.1148/radiol.2522081550 }}</ref><ref>{{cite journal | vauthors = Cleveland Z, Möller H, Hedlund L, Driehuys B | title = Continuously infusing hyperpolarized 129Xe into flowing aqueous solutions using hydrophobic gas exchange membranes | journal = The Journal of Physical Chemistry | volume = 113 | issue = 37 | pages = 12489–12499 | date = 2009 | pmid = 19702286 | pmc = 2747043 | doi = 10.1021/jp9049582 | bibcode = 2009JPCB..11312489C }}</ref>

Xenon-129 is used as a visualization agent in MRI scans. When a patient inhales hyperpolarized xenon-129 ventilation and gas exchange in the lungs can be imaged and quantified. Unlike xenon-133, xenon-129 is non-ionizing and is safe to be inhaled with no adverse effects.<ref>{{Cite journal | vauthors = Marshall H, Stewart NJ, Chan HF, Rao M, Norquay G, Wild JM | title = In vivo methods and applications of xenon-129 magnetic resonance | journal = Progress in Nuclear Magnetic Resonance Spectroscopy | volume = 122 | pages = 42–62 | date = February 1, 2021 | pmid = 33632417 | pmc = 7933823 | doi = 10.1016/j.pnmrs.2020.11.002 | language = en | issn = 0079-6565 | bibcode = 2021PNMRS.122...42M }}</ref>

==== Surgery ====
The xenon chloride [[excimer laser]] has certain dermatological uses.<ref>{{cite journal | vauthors = Baltás E, Csoma Z, Bodai L, Ignácz F, Dobozy A, Kemény L | title = Treatment of atopic dermatitis with the xenon chloride excimer laser | journal = Journal of the European Academy of Dermatology and Venereology | volume = 20 | issue = 6 | pages = 657–660 | date = Jul 2006 | pmid = 16836491 | doi = 10.1111/j.1468-3083.2006.01495.x | s2cid = 20156819 }}</ref>

=== NMR spectroscopy ===
Because of the xenon atom's large, flexible outer electron shell, the [[nuclear magnetic resonance|NMR]] spectrum changes in response to surrounding conditions and can be used to monitor the surrounding chemical circumstances. For instance, xenon dissolved in water, xenon dissolved in hydrophobic solvent, and xenon associated with certain proteins can be distinguished by NMR.<ref>{{cite journal | vauthors = Luhmer M, Dejaegere A, Reisse J | title = Interpretation of the solvent effect on the screening constant of Xe-129 | journal = Magnetic Resonance in Chemistry | volume = 27 | issue = 10 | pages = 950–952 | date = 1989 | doi = 10.1002/mrc.1260271009 | s2cid = 95432492 }}</ref><ref>{{cite journal | vauthors = Rubin SM, Spence MM, Goodson BM, Wemmer DE, Pines A | title = Evidence of nonspecific surface interactions between laser-polarized xenon and myoglobin in solution | journal = [[Proceedings of the National Academy of Sciences USA]] | volume = 97 | issue = 17 | pages = 9472–9475 | date = August 15, 2000 | pmid = 10931956 | pmc = 16888 | doi = 10.1073/pnas.170278897 | bibcode = 2000PNAS...97.9472R | doi-access = free }}</ref>

Hyperpolarized xenon can be used by [[Surface science|surface chemists]]. Normally, it is difficult to characterize surfaces with NMR because signals from a surface are overwhelmed by signals from the atomic nuclei in the bulk of the sample, which are much more numerous than surface nuclei. However, nuclear spins on solid surfaces can be selectively polarized by [[Proton Enhanced Nuclear Induction Spectroscopy|transferring spin polarization to them]] from hyperpolarized xenon gas. This makes the surface signals strong enough to measure and distinguish from bulk signals.<ref>{{cite journal | vauthors = Raftery D, MacNamara E, Fisher G, Rice CV, Smith J | title = Optical Pumping and Magic Angle Spinning: Sensitivity and Resolution Enhancement for Surface NMR Obtained with Laser-Polarized Xenon | journal = Journal of the American Chemical Society | volume = 119 | issue = 37 | pages = 8746–8747 | date = 1997 | doi = 10.1021/ja972035d | bibcode = 1997JAChS.119.8746R }}</ref><ref>{{cite journal | vauthors = Gaede HC, Song YQ, Taylor RE, Munson EJ, Reimer JA, Pines A | title = High-field cross polarization NMR from laser-polarized xenon to surface nuclei | journal = Applied Magnetic Resonance | volume = 8 | issue = 3–4 | pages = 373–384 | date = 1995 | doi = 10.1007/BF03162652 | s2cid = 34971961 }}</ref>

=== Other ===
[[File:Xenon ion engine prototype.png|thumb|A prototype of a xenon ion engine being tested at NASA's [[Jet Propulsion Laboratory]] | alt=A metal cylinder with electrodes attached to its side. Blue diffuse light is coming out of the tube.]]
In [[Nuclear physics|nuclear energy]] studies, xenon is used in [[bubble chamber]]s,<ref>{{cite book | vauthors = Galison PL | title = Image and Logic: A Material Culture of Microphysics | pages = 339 | date = 1997 | url = https://books.google.com/books?id=HnRDiDtO5yoC&pg=PA339 | publisher = University of Chicago Press | isbn = 978-0-226-27917-6 }}</ref> probes, and in other areas where a high [[Molecular mass|molecular weight]] and inert chemistry is desirable. A by-product of [[nuclear weapon]] testing is the release of radioactive [[isotopes of xenon|xenon-133 and xenon-135]]. These isotopes are monitored to ensure compliance with nuclear [[Test Ban Treaty (disambiguation)|test ban treaties]],<ref>{{cite journal | vauthors = Fontaine JP, Pointurier F, Blanchard X, Taffary T | title = Atmospheric xenon radioactive isotope monitoring | journal = Journal of Environmental Radioactivity | volume = 72 | issue = 1–2 | pages = 129–135 | date = 2004 | pmid = 15162864 | doi = 10.1016/S0265-931X(03)00194-2 | bibcode = 2004JEnvR..72..129F }}</ref> and to confirm nuclear tests by states such as [[North Korea]].<ref>{{cite journal | vauthors = Garwin RL, Von Hippel FN, Smith H | title = A Technical Analysis: Deconstructing North Korea's October 9 Nuclear Test | journal = Arms Control Today | volume = 38 | issue = 9 | date = November 2006 | publisher = Arms Control Association | access-date = March 26, 2009 | url = http://www.armscontrol.org/act/2006_11/tech }}</ref>

Liquid xenon is used in [[Calorimeter (particle physics)|calorimeters]]<ref>{{cite journal | vauthors = Gallucci G | title = The MEG liquid xenon calorimeter | journal = Journal of Physics: Conference Series | volume = 160 | issue = 1 | article-number = 012011 | date = 2009 | doi = 10.1088/1742-6596/160/1/012011 | bibcode = 2009JPhCS.160a2011G | doi-access = free }}</ref> to measure [[gamma ray]]s, and as a detector of hypothetical [[weakly interacting massive particles]], or WIMPs. When a WIMP collides with a xenon nucleus, theory predicts it will impart enough energy to cause ionization and [[Scintillation (physics)|scintillation]]. Liquid xenon is useful for these experiments because its density makes dark matter interaction more likely and it permits a quiet detector through self-shielding.

Xenon is the preferred [[propellant]] for [[ion propulsion]] of [[spacecraft]] because it has low [[ionization potential]] per [[Atomic mass|atomic weight]] and can be stored as a liquid at near [[room temperature]] (under high pressure), yet easily evaporated to feed the engine. Xenon is inert, environmentally friendly, and less corrosive to an [[ion engine]] than other fuels such as [[Mercury (element)|mercury]] or [[caesium]]. Xenon was first used for satellite ion engines during the 1970s.<ref>{{cite web | vauthors = Zona K | title = Innovative Engines: Glenn Ion Propulsion Research Tames the Challenges of 21st century Space Travel | date = March 17, 2006 | url = http://www.nasa.gov/centers/glenn/about/fs08grc.html | publisher = NASA | access-date = October 4, 2007 | url-status = dead | archive-url = https://web.archive.org/web/20070915023928/http://www.nasa.gov/centers/glenn/about/fs08grc.html | archive-date = September 15, 2007 }}</ref> It was later employed as a propellant for JPL's [[Deep Space 1]] probe, Europe's [[SMART-1]] spacecraft<ref name="Saccoccia_2006">{{cite news | vauthors = Saccoccia G, del Amo JG, Estublier D | title = Ion engine gets SMART-1 to the Moon | date = August 31, 2006 | publisher = ESA | url = http://www.esa.int/SPECIALS/SMART-1/SEMLZ36LARE_0.html | access-date = October 1, 2007 }}</ref> and for the three ion propulsion engines on NASA's [[Dawn Spacecraft]].<ref>{{cite web | title = Dawn Launch: Mission to Vesta and Ceres | url = http://www.jpl.nasa.gov/news/press_kits/dawn-launch.pdf | publisher = NASA | access-date = October 1, 2007 }}</ref>

Chemically, the [[perxenate]] compounds are used as [[oxidizing agent]]s in [[analytical chemistry]]. [[Xenon difluoride]] is used as an etchant for [[silicon]], particularly in the production of [[microelectromechanical systems]] (MEMS).<ref>{{cite conference | vauthors = Brazzle JD, Dokmeci MR, Mastrangelo CH | title = Modeling and Characterization of Sacrificial Polysilicon Etching Using Vapor-Phase Xenon Difluoride | location = Maastricht, Netherlands | pages = 737–740 | date = August 1, 1975 | work = Proceedings 17th IEEE International Conference on Micro Electro Mechanical Systems (MEMS) | publisher = IEEE | isbn = 978-0-7803-8265-7 }}</ref> The anticancer drug [[Fluorouracil|5-fluorouracil]] can be produced by reacting xenon difluoride with [[uracil]].<ref>{{cite web | vauthors = Staff | title = Neil Bartlett and the Reactive Noble Gases | year = 2007 | url = https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/bartlettnoblegases.html | publisher = American Chemical Society | access-date = June 5, 2012 }}</ref> Xenon is also used in [[X-ray crystallography|protein crystallography]]. Applied at pressures from 0.5 to 5&nbsp;[[Pascal (unit)|MPa]] (5 to 50&nbsp;[[atmosphere (unit)|atm]]) to a protein crystal, xenon atoms bind in predominantly [[Hydrophobe|hydrophobic]] cavities, often creating a high-quality, isomorphous, heavy-atom derivative that can be used for solving the [[phase problem]].<ref>{{cite web | vauthors = Staff | title = Protein Crystallography: Xenon and Krypton Derivatives for Phasing | date = December 21, 2004 | url = http://www.srs.ac.uk/px/facilities/xenon_notes_1.html | archive-url = https://web.archive.org/web/20050316174727/http://www.srs.ac.uk/px/facilities/xenon_notes_1.html | archive-date = March 16, 2005 | publisher = Daresbury Laboratory, PX | access-date = October 1, 2007 }}</ref><ref>{{cite book | vauthors = Drenth J, Mesters J | chapter = The Solution of the Phase Problem by the Isomorphous Replacement Method | title = Principles of Protein X-Ray Crystallography | location = New York | pages = [https://archive.org/details/principlesprotei00dren_066/page/n134 123]–171 | year = 2007 | doi = 10.1007/0-387-33746-6_7 | url = https://archive.org/details/principlesprotei00dren_066 | url-access = limited | publisher = [[Springer Science+Business Media | Springer]] | isbn = 978-0-387-33334-2 | edition = 3rd }}</ref>
{{clear}}

== Precautions ==
{{Chembox
| container_only = yes
| Section7={{Chembox Hazards
| NFPA-H = 0
| NFPA-F = 0
| NFPA-R = 0
| NFPA-S = SA
| NFPA_ref = <ref name="NFPA704Xe">{{cite report | title = Safety Data Sheet: Xenon | date = February 15, 2018 | url = https://www.airgas.com/msds/001050.pdf | publisher = [[Airgas]] }}</ref>
 }}
}}

Xenon gas can be safely kept in normal sealed glass or metal containers at [[standard temperature and pressure]]. However, it readily dissolves in most plastics and rubber, and will gradually escape from a container sealed with such materials.<ref>{{
cite journal | vauthors = LeBlanc AD, Johnson PC | title = The handling of xenon-133 in clinical studies | journal = Physics in Medicine and Biology | volume = 16 | issue = 1 | pages = 105–109 | date = Jan 1971 | pmid = 5579743 | doi = 10.1088/0031-9155/16/1/310 | bibcode = 1971PMB....16..105L | s2cid = 250787824 }}</ref> Xenon is non-[[toxic]], although it does dissolve in blood and belongs to a select group of substances that penetrate the [[blood–brain barrier]], causing mild to full surgical [[anesthesia]] when inhaled in high concentrations with oxygen.<ref name="Finkel_1968" />

The [[speed of sound]] in xenon gas (169&nbsp;m/s) is less than that in air<ref>169.44&nbsp;m/s in xenon (at {{cvt|0|C}} and 107&nbsp;kPa), compared to 344&nbsp;m/s in air. See: {{cite journal | vauthors = Vacek V, Hallewell G, Lindsay S | title = Velocity of sound measurements in gaseous per-fluorocarbons and their mixtures | journal = Fluid Phase Equilibria | volume = 185 | issue = 1–2 | pages = 305–314 | year = 2001 | doi = 10.1016/S0378-3812(01)00479-4 | bibcode = 2001FlPEq.185..305V }}</ref> because the average velocity of the heavy xenon atoms is less than that of nitrogen and oxygen molecules in air. Hence, xenon vibrates more slowly in the [[vocal tract|vocal cords]] when exhaled and produces lowered voice tones (low-frequency-enhanced sounds, but the [[fundamental frequency]] or [[Pitch (music)|pitch]] does not change), an effect opposite to the high-toned voice produced in [[helium]]. Specifically, when the vocal tract is filled with xenon gas, its natural resonant frequency becomes lower than when it is filled with air. Thus, the low frequencies of the sound wave produced by the same direct vibration of the [[vocal cords]] would be enhanced, resulting in a change of the [[timbre]] of the sound amplified by the vocal tract. Like helium, xenon does not satisfy the body's need for oxygen, and it is both a simple [[asphyxiant gas|asphyxiant]] and an anesthetic more powerful than nitrous oxide; consequently, and because xenon is expensive, many universities have prohibited the voice stunt as a general chemistry demonstration.<ref>{{Cite web | title = Helium Voice or other effects | url = https://www.bbc.co.uk/safety/resources/aztopics/sfx-helium-voice-effects | access-date = May 6, 2024 | publisher = BBC}}</ref> The gas [[sulfur hexafluoride]] is similar to xenon in molecular weight (146 versus 131), less expensive, and though an asphyxiant, not toxic or anesthetic; it is often substituted in these demonstrations.<ref>{{cite web | vauthors = Spangler S | title = Anti-Helium – Sulfur Hexafluoride | date = 2007 | url = http://www.stevespanglerscience.com/experiment/from-donald-duck-to-barry-white-how-gases-change-your-voice | publisher = Steve Spangler Science | access-date = October 4, 2007 | url-status = dead | archive-url = https://web.archive.org/web/20070929003314/http://www.stevespanglerscience.com/experiment/from-donald-duck-to-barry-white-how-gases-change-your-voice | archive-date = September 29, 2007 }}</ref>

Dense gases such as xenon and sulfur hexafluoride can be breathed safely when mixed with at least 20% oxygen. Xenon at 80% concentration along with 20% oxygen rapidly produces the unconsciousness of general anesthesia. Breathing mixes gases of different densities very effectively and rapidly so that heavier gases are purged along with the oxygen, and do not accumulate at the bottom of the lungs.<ref>{{cite journal | vauthors = Yamaguchi K, Soejima K, Koda E, Sugiyama N | title = Inhaling Gas With Different CT Densities Allows Detection of Abnormalities in the Lung Periphery of Patients With Smoking-Induced COPD | journal = [[chest (journal) | chest]] | volume = 120 | issue = 6 | pages = 1907–1916 | date = Dec 2001 | pmid = 11742921 | doi = 10.1378/chest.120.6.1907 }}</ref> There is, however, a danger associated with any heavy gas in large quantities: it may sit invisibly in a container, and a person who enters an area filled with an odorless, colorless gas may be asphyxiated without warning. Xenon is rarely used in large enough quantities for this to be a concern, though the potential for danger exists any time a tank or container of xenon is kept in an unventilated space.<ref>{{cite web | vauthors = Staff | title = Cryogenic and Oxygen Deficiency Hazard Safety | date = August 1, 2007 | url = http://www-group.slac.stanford.edu/esh/hazardous_substances/cryogenic/p_hazards.htm | publisher = Stanford Linear Accelerator Center | access-date = October 10, 2007 | archive-url = https://web.archive.org/web/20070609173316/http://www-group.slac.stanford.edu/esh/hazardous_substances/cryogenic/p_hazards.htm | archive-date = June 9, 2007 }}</ref>

Water-soluble xenon compounds such as [[monosodium xenate]] are moderately toxic, but have a very short half-life in the body – [[intravenous]]ly injected xenate is reduced to elemental xenon in about a minute.<ref name="Finkel_1968">{{cite web | vauthors = Finkel AJ, Katz JJ, Miller CE | title = Metabolic and toxicological effects of water-soluble xenon compounds are studied | date = April 1, 1968 | url = https://ntrs.nasa.gov/citations/19680000076 | publisher = NASA | access-date = March 18, 2022 }}</ref>

== See also ==
{{portal|Chemistry}}
* [[Levitation (physics)#Buoyant levitation|Buoyant levitation]]
* [[Noble gases]]
* [[Penning mixture]]

== Notes ==
{{notelist}}

== References ==
{{reflist|30em}}

== External links ==
{{Sister project links |wikt=xenon |commons=y |b=no |n=no |q=no |s=no |v=Xenon atom}}
* [http://www.periodicvideos.com/videos/054.htm Xenon] at ''[[The Periodic Table of Videos]]'' (University of Nottingham)
* [https://wwwrcamnl.wr.usgs.gov/isoig/period/xe_iig.html USGS Periodic Table – Xenon] {{Webarchive|url=https://web.archive.org/web/20131213053952/http://wwwrcamnl.wr.usgs.gov/isoig/period/xe_iig.html |date=December 13, 2013 }}
* [http://environmentalchemistry.com/yogi/periodic/Xe.html EnvironmentalChemistry.com – Xenon]
* [http://nobelprize.org/nobel_prizes/chemistry/laureates/1904/ramsay-lecture.html Sir William Ramsay's Nobel-Prize lecture (1904)]

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