Isotopes of xenon

{{Short description|none}} {{Infobox xenon isotopes}} Naturally occurring xenon (₅₄Xe) consists of nine isotopes: seven stable isotopes and two very long-lived radioactive isotopes: double electron capture has been observed in ¹²⁴Xe (half-life 1.1&nbsp;±&nbsp;0.2_stat&nbsp;±&nbsp;0.1_sys{{e|22}} years),<ref name="Aprile2022"/> and double beta decay in ¹³⁶Xe (half-life {{nowrap|2.18 {{e|21}} years}}), which are among the longest measured half-lives of all nuclides. The isotopes ¹²⁶Xe and ¹³⁴Xe are also predicted to undergo double beta decay, but such decay processes have not been observed.<ref name="xenon2b">{{cite journal |last1=Barros |first1=N. |last2=Thurn |first2=J. |last3=Zuber |first3=K. |title=Double beta decay searches of ¹³⁴Xe, ¹²⁶Xe, and ¹²⁴Xe with large scale Xe detectors |date=2014 |journal=Journal of Physics G |volume=41 |issue=11 |pages=115105–1–115105–12 |doi=10.1088/0954-3899/41/11/115105 |arxiv=1409.8308 |bibcode=2014JPhG...41k5105B |s2cid=116264328 }}</ref><ref name="134Xe2024">{{cite journal |last1=Yan |first1=X. |last2=Cheng |first2=Z. |last3=Abdukerim |first3=A. |display-authors=etal |title=Searching for two-neutrino and neutrinoless double beta decay of ¹³⁴Xe with the PandaX-4T experiment |journal=Physical Review Letters |volume=132 |number=152502 |date=2024 |article-number=152502 |doi=10.1103/PhysRevLett.132.152502|pmid=38682998 |arxiv=2312.15632 |bibcode=2024PhRvL.132o2502Y }}</ref> Artificial unstable isotopes have been prepared from ¹⁰⁸Xe to ¹⁵⁰Xe, the longest-lived of which is ¹²⁷Xe with a half-life of 36.342 days. All other nuclides have half-lives less than 12 days, most less than one hour. The shortest-lived isotope, ¹⁰⁸Xe,<ref name="Xe108">{{cite journal |last=Auranen |first=K. |display-authors=etal |date=2018 |title=Superallowed α decay to doubly magic ¹⁰⁰Sn |journal=Physical Review Letters |volume=121 |issue=18 |article-number=182501 |doi=10.1103/PhysRevLett.121.182501 |pmid=30444390 |bibcode=2018PhRvL.121r2501A |url=https://www.pure.ed.ac.uk/ws/files/77942573/PhysRevLett.121.pdf |doi-access=free }}</ref> has a half-life of 58&nbsp;μs, and is the heaviest known nuclide with equal numbers of protons and neutrons. Of known isomers, the longest-lived is ^131mXe with a half-life of 11.95 days, the second longest of all xenon's nuclides.

¹²⁹Xe is produced by beta decay of natural or artificial ¹²⁹I (half-life 16.1 million years); ^131mXe, ¹³³Xe, ^133mXe, and ¹³⁵Xe are some of the fission products of both ²³⁵U and ²³⁹Pu, so are used as indicators of nuclear explosions.

The artificial isotope ¹³⁵Xe is of considerable significance in the operation of nuclear fission reactors. ¹³⁵Xe has a huge cross section for thermal neutrons, 2.65 million barns, so it acts as a neutron absorber or "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. Because of this effect, designers must make provisions to increase the reactor's reactivity (the number of neutrons per fission that go on to fission other atoms of nuclear fuel) over the initial value needed to start the chain reaction. For the same reason, the xenon fission products produced in a nuclear explosion and a power plant differ significantly as a large share of {{chem|135|Xe}} will absorb neutrons in a steady state reactor, while in a bomb it can be assumed that none of the {{chem|135|I}} will have had time to decay to xenon before the explosion disperses it, removing it from the neutron radiation.

Relatively high concentrations of radioactive xenon isotopes are also found emanating from nuclear reactors due to the release of this fission gas from cracked fuel rods or fissioning of uranium in cooling water.{{citation needed|date=April 2017}} The concentrations of these isotopes are still usually low compared to the naturally occurring radioactive noble gas ²²²Rn.

Because xenon is a tracer for two parent isotopes, <!-- I-129 is one, what is the other here? --> Xe isotope ratios in meteorites are a powerful tool for studying the formation of the Solar System. The I-Xe method of dating gives the time elapsed between nucleosynthesis and the condensation of a solid object from the solar nebula (xenon being a gas, only that part of it that formed after condensation will be present inside the object). Xenon isotopes are also a powerful tool for understanding terrestrial differentiation. Excess ¹²⁹Xe found in carbon dioxide well gases from New Mexico was believed to be from the decay of mantle-derived gases soon after Earth's formation.<ref>{{cite journal | last1 = Boulos | first1 = M. S. | last2=Manuel |first2=O. K. | title = The xenon record of extinct radioactivities in the Earth. | journal = Science | volume = 174 | issue = 4016 | pages = 1334–1336 | year = 1971 | doi = 10.1126/science.174.4016.1334 | pmid = 17801897 |bibcode = 1971Sci...174.1334B | s2cid = 28159702 }}</ref> It has been suggested{{clarify|date=July 2025}} that the isotopic composition of atmospheric xenon fluctuated prior to the GOE before stabilizing, perhaps as a result of the rise in atmospheric O₂.<ref name="ardoin2022">{{cite journal | title = The end of the isotopic evolution of atmospheric xenon | last1 = Ardoin | first1 = L. | last2 = Broadley | first2 = M.W. | last3 = Almayrac | first3 = M. | last4 = Avice | first4 = G. | last5 = Byrne | first5 = D.J. | last6 = Tarantola | first6 = A. | last7 = Lepland | first7 = A. | last8 = Saito | first8 = T. | last9 = Komiya | first9 = T. | last10 = Shibuya | first10 = T. | last11 = Marty | first11 = B. | journal = Geochemical Perspectives Letters | volume = 20 | pages = 43–47 | date = 2022 | doi = 10.7185/geochemlet.2207| bibcode = 2022GChPL..20...43A | s2cid = 247399987 | doi-access = free | hdl = 2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/342396 | hdl-access = free }}</ref>

== List of isotopes == {{Isotopes table | symbol = Xe | refs = NUBASE2020, AME2020 II, <!-- updated 2024-10-01 --> IsotopeFRIB, IsomerFRIB | notes = m, unc(), mass#, hl-nst, spin(), spin#, daughter-st, EC, IT, n, discoveryname }} |-id=Xenon-108 | ¹⁰⁸Xe{{refn|group="n"|Heaviest known isotope with equal numbers of protons and neutrons}} | style="text-align:right" | 54 | style="text-align:right" | 54 | 107.95423(41) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/108.pdf 2018] | 72(35)&nbsp;μs | α | ¹⁰⁴Te | 0+ | | |-id=Xenon-109 | ¹⁰⁹Xe | style="text-align:right" | 54 | style="text-align:right" | 55 | 108.95076(32)#<ref name="nies2025">{{cite journal |last1=Nies |first1=L. |last2=Atanasov |first2=D. |last3=Athanasakis-Kaklamanakis |first3=M. |last4=Au |first4=M. |last5=Bernerd |first5=C. |last6=Blaum |first6=K. |last7=Chrysalidis |first7=K. |last8=Fischer |first8=P. |last9=Heinke |first9=R. |last10=Klink |first10=C. |last11=Lange |first11=D. |last12=Lunney |first12=D. |last13=Manea |first13=V. |last14=Marsh |first14=B. A. |last15=Müller |first15=M. |last16=Mougeot |first16=M. |last17=Naimi |first17=S. |last18=Schweiger |first18=Ch. |last19=Schweikhard |first19=L. |last20=Wienholtz |first20=F. |title=Refining the nuclear mass surface with the mass of Sn 103 |journal=Physical Review C |date=9 January 2025 |volume=111 |issue=1 |article-number=014315 |doi=10.1103/PhysRevC.111.014315|doi-access=free }}</ref> | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/109.pdf 2006] | 13(2)&nbsp;ms | α | ¹⁰⁵Te | (7/2+) | | |-id=Xenon-110 | rowspan=2|¹¹⁰Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 56 | rowspan=2|109.94426(11) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/110.pdf 1981] | rowspan=2|93(3)&nbsp;ms | α (64%) | ¹⁰⁶Te | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺ (36%) | ¹¹⁰I |-id=Xenon-111 | rowspan=2|¹¹¹Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 57 | rowspan=2|110.941460(64)<ref name="nies2025"/> | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/111.pdf 1979] | rowspan=2|740(200)&nbsp;ms | β⁺ (89.6%) | ¹¹¹I | rowspan=2|5/2+# | rowspan=2| | rowspan=2| |- | α (10.4%) | ¹⁰⁷Te |-id=Xenon-112 | rowspan=2|¹¹²Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 58 | rowspan=2|111.9355591(89) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/112.pdf 1978] | rowspan=2|2.7(8)&nbsp;s | β⁺ (98.8%) | ¹¹²I | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (1.2%) | ¹⁰⁸Te |-id=Xenon-113 | rowspan=4|¹¹³Xe | rowspan=4 style="text-align:right" | 54 | rowspan=4 style="text-align:right" | 59 | rowspan=4|112.9332217(73) | rowspan=4 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/113.pdf 1973] | rowspan=4|2.74(8)&nbsp;s | β⁺ (92.98%) | ¹¹³I | rowspan=4|5/2+# | rowspan=4| | rowspan=4| |- | β⁺, p (7%) | ¹¹²Te |- | α (?%) | ¹⁰⁹Te |- | β⁺, α (~0.007%) | ¹⁰⁹Sb |-id=Xenon-113m | style="text-indent:1em" | ^113mXe | colspan="3" style="text-indent:2em" | 403.6(14)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/113Xe-1.pdf 2013] | 6.9(3)&nbsp;μs | IT | ¹¹³Xe | (11/2−) | | |-id=Xenon-114 | ¹¹⁴Xe | style="text-align:right" | 54 | style="text-align:right" | 60 | 113.927980(12) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/114.pdf 1977] | 10.0(4)&nbsp;s | β⁺ | ¹¹⁴I | 0+ | | |-id=Xenon-115 | rowspan=2|¹¹⁵Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 61 | rowspan=2|114.926294(13) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/115.pdf 1969] | rowspan=2|18(3)&nbsp;s | β⁺ (99.66%) | ¹¹⁵I | rowspan=2|(5/2+) | rowspan=2| | rowspan=2| |- | β⁺, p (0.34%) | ¹¹⁴Te |-id=Xenon-116 | ¹¹⁶Xe | style="text-align:right" | 54 | style="text-align:right" | 62 | 115.921581(14) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/116.pdf 1969] | 59(2)&nbsp;s | β⁺ | ¹¹⁶I | 0+ | | |-id=Xenon-117 | rowspan=2|¹¹⁷Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 63 | rowspan=2|116.920359(11) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/117.pdf 1969] | rowspan=2|61(2)&nbsp;s | β⁺ | ¹¹⁷I | rowspan=2|5/2+ | rowspan=2| | rowspan=2| |- | β⁺, p (0.0029%) | ¹¹⁶Te |-id=Xenon-118 | ¹¹⁸Xe | style="text-align:right" | 54 | style="text-align:right" | 64 | 117.916179(11) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/118.pdf 1965] | 3.8(9)&nbsp;min | β⁺ | ¹¹⁸I | 0+ | | |-id=Xenon-119 | rowspan=2|¹¹⁹Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 65 | rowspan=2|118.915411(11) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/119.pdf 1965] | rowspan=2|5.8(3)&nbsp;min | β⁺ (79%) | ¹¹⁹I | rowspan=2|5/2+ | rowspan=2| | rowspan=2| |- | EC (21%) | ¹¹⁹I |-id=Xenon-120 | ¹²⁰Xe | style="text-align:right" | 54 | style="text-align:right" | 66 | 119.911784(13) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/120.pdf 1965] | 46.0(6)&nbsp;min | β⁺ | ¹²⁰I | 0+ | | |-id=Xenon-121 | ¹²¹Xe | style="text-align:right" | 54 | style="text-align:right" | 67 | 120.911453(11) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/121.pdf 1952] | 40.1(20)&nbsp;min | β⁺ | ¹²¹I | 5/2+ | | |-id=Xenon-122 | ¹²²Xe | style="text-align:right" | 54 | style="text-align:right" | 68 | 121.908368(12) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/122.pdf 1952] | 20.1(1)&nbsp;h | EC | ¹²²I | 0+ | | |-id=Xenon-123 | ¹²³Xe | style="text-align:right" | 54 | style="text-align:right" | 69 | 122.908482(10) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/123.pdf 1952] | 2.08(2)&nbsp;h | β⁺ | ¹²³I | 1/2+ | | |-id=Xenon-123m | style="text-indent:1em" | ^123mXe | colspan="3" style="text-indent:2em" | 185.18(11)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/123Xe-1.pdf 1970] | 5.49(26)&nbsp;μs | IT | ¹²³Xe | 7/2− | | |-id=Xenon-124 | ¹²⁴Xe<ref group="n" name="PN">Primordial radionuclide</ref> | style="text-align:right" | 54 | style="text-align:right" | 70 | 123.9058852(15) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/124.pdf 1922] | '''1.1(2){{e|22}}&nbsp;y'''<ref name="Aprile2022"/> | Double EC | '''¹²⁴Te''' | 0+ | 9.5(5)×10⁻⁴ | |-id=Xenon-125 | ¹²⁵Xe | style="text-align:right" | 54 | style="text-align:right" | 71 | 124.9063876(15) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/125.pdf 1950] | 16.87(8)&nbsp;h | EC / β⁺ | ¹²⁵I | 1/2+ | | |-id=Xenon-125m1 | style="text-indent:1em" | ^125m1Xe | colspan="3" style="text-indent:2em" | 252.61(14)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/125Xe-1.pdf 1954] | 56.9(9)&nbsp;s | IT | ¹²⁵Xe | 9/2− | | |-id=Xenon-125m2 | style="text-indent:1em" | ^125m2Xe | colspan="3" style="text-indent:2em" | 295.89(15)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/125Xe-2.pdf 1979] | 0.14(3)&nbsp;μs | IT | ¹²⁵Xe | 7/2+ | | |-id=Xenon-126 | ¹²⁶Xe | style="text-align:right" | 54 | style="text-align:right" | 72 | 125.904297422(6) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/126.pdf 1922] | colspan=3 align=center|'''Observationally Stable'''<ref group="n">Theoretically capable of 2EC decay to '''¹²⁶Te'''</ref> | 0+ | 8.9(3)×10⁻⁴ | |-id=Xenon-127 | ¹²⁷Xe | style="text-align:right" | 54 | style="text-align:right" | 73 | 126.9051836(44) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/127.pdf 1950] | 36.342(3)&nbsp;d | EC | '''¹²⁷I''' | 1/2+ | | |-id=Xenon-127m | style="text-indent:1em" | ^127mXe | colspan="3" style="text-indent:2em" | 297.10(8)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/127Xe-1.pdf 1954] | 69.2(9)&nbsp;s | IT | ¹²⁷Xe | 9/2− | | |-id=Xenon-128 | ¹²⁸Xe | style="text-align:right" | 54 | style="text-align:right" | 74 | 127.9035307534(56) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/128.pdf 1922] | colspan=3 align=center|'''Stable''' | 0+ | 0.01910(13) | |-id=Xenon-128m | style="text-indent:1em" | ^128mXe | colspan="3" style="text-indent:2em" | 2787.2(3)&nbsp;keV | style="text-align:center" | (1984)<ref group="n">Half-life shorter than 100ns, not included in discovery database</ref> | 83(2)&nbsp;ns | IT | '''¹²⁸Xe''' | 8− | | |-id=Xenon-129 | ¹²⁹Xe<ref group="n">Used in a method of radiodating groundwater and to infer certain events in the Solar System's history</ref> | style="text-align:right" | 54 | style="text-align:right" | 75 | 128.9047808574(54) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/129.pdf 1920] | colspan=3 align=center|'''Stable''' | 1/2+ | 0.26401(138) | |-id=Xenon-129m | style="text-indent:1em" | ^129mXe | colspan="3" style="text-indent:2em" | 236.14(3)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/129Xe-1.pdf 1951] | 8.88(2)&nbsp;d | IT | '''¹²⁹Xe''' | 11/2− | | |-id=Xenon-130 | ¹³⁰Xe | style="text-align:right" | 54 | style="text-align:right" | 76 | 129.903509346(10) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/130.pdf 1922] | colspan=3 align=center|'''Stable''' | 0+ | 0.04071(22) |-id=Xenon-131 | ¹³¹Xe<ref group="n" name="FP">Fission product</ref> | style="text-align:right" | 54 | style="text-align:right" | 77 | 130.9050841281(55) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/131.pdf 1920] | colspan=3 align=center|'''Stable''' | 3/2+ | 0.21232(51) | |-id=Xenon-131m | style="text-indent:1em" | ^131mXe<ref group="n" name="FP" /> | colspan="3" style="text-indent:2em" | 163.930(8)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/131Xe-1.pdf 1949] | 11.948(12)&nbsp;d | IT | '''¹³¹Xe''' | 11/2− | | |-id=Xenon-132 | ¹³²Xe<ref group="n" name="FP" /> | style="text-align:right" | 54 | style="text-align:right" | 78 | 131.9041550835(54) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/132.pdf 1920] | colspan=3 align=center|'''Stable''' | 0+ | 0.26909(55) | |-id=Xenon-132m | style="text-indent:1em" | ^132mXe | colspan="3" style="text-indent:2em" | 2752.21(17)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/132Xe-1.pdf 1965] | 8.39(11)&nbsp;ms | IT | '''¹³²Xe''' | (10+) | | |-id=Xenon-133 | ¹³³Xe<ref group="n" name="FP" /><ref group="n">Has medical uses</ref> | style="text-align:right" | 54 | style="text-align:right" | 79 | 132.9059107(26) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/133.pdf 1940] | 5.2474(5)&nbsp;d | β⁻ | '''¹³³Cs''' | 3/2+ | | |-id=Xenon-133m1 | style="text-indent:1em" | ^133m1Xe<ref group="n" name="FP" /> | colspan="3" style="text-indent:2em" | 233.221(15)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/133Xe-1.pdf 1950] | 2.198(13)&nbsp;d | IT | ¹³³Xe | 11/2− | | |-id=Xenon-133m2 | style="text-indent:1em" | ^133m2Xe | colspan="3" style="text-indent:2em" | 2147(20)#&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/133Xe-2.pdf 2017] | 8.64(13)&nbsp;ms | IT | ¹³³Xe | (23/2+) | | |-id=Xenon-134 | ¹³⁴Xe<ref group="n" name="FP" /> | style="text-align:right" | 54 | style="text-align:right" | 80 | 133.905393030(6) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/134.pdf 1920] | colspan=3 align=center|'''Observationally Stable'''{{refn|group="n"|Theoretically capable of β⁻β⁻ decay to '''¹³⁴Ba''' with a half-life over {{val|2.8|e=22}} years<ref name=134Xe2024/>}} | 0+ | 0.10436(35) | |-id=Xenon-134m1 | style="text-indent:1em" | ^134m1Xe | colspan="3" style="text-indent:2em" | 1965.5(5)&nbsp;keV | style="text-align:center" | (1968)<ref group="n">Only published in a conference proceeding and not a refereed journal.</ref> | 290(17)&nbsp;ms | IT | '''¹³⁴Xe''' | 7− | | |-id=Xenon-134m2 | style="text-indent:1em" | ^134m2Xe | colspan="3" style="text-indent:2em" | 3025.2(15)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/134Xe-1.pdf 2001] | 5(1)&nbsp;μs | IT | '''¹³⁴Xe''' | (10+) | | |-id=Xenon-135 | ¹³⁵Xe<ref group="n">Most powerful known neutron absorber, produced in nuclear power plants as a decay product of ¹³⁵I, itself a decay product of ¹³⁵Te, a fission product. Normally absorbs neutrons in the high neutron flux environments to become '''''¹³⁶Xe'''''; see iodine pit for more information</ref> | style="text-align:right" | 54 | style="text-align:right" | 81 | 134.9072314(39) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/135.pdf 1940] | 9.14(2)&nbsp;h | β⁻ | ¹³⁵Cs | 3/2+ | | |-id=Xenon-135m | rowspan=2 style="text-indent:1em" | ^135mXe<ref group="n" name="FP" /> | rowspan=2 colspan="3" style="text-indent:2em" | 526.551(13)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/135Xe-1.pdf 1943] | rowspan=2|15.29(5)&nbsp;min | IT (99.70%) | ¹³⁵Xe | rowspan=2|11/2− | rowspan=2| | rowspan=2| |- | β⁻ (0.30%) | ¹³⁵Cs |-id=Xenon-136 | ¹³⁶Xe<ref group="n" name="FP" /><ref group="n" name="PN">Primordial radionuclide</ref> | style="text-align:right" | 54 | style="text-align:right" | 82 | 135.907214474(7) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/136.pdf 1920] | '''2.18(5){{e|21}}&nbsp;y''' |β⁻β⁻ | '''¹³⁶Ba''' | 0+ | 0.08857(72) | |-id=Xenon-136m | style="text-indent:1em" | ^136mXe | colspan="3" style="text-indent:2em" | 1891.74(7)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/54/136Xe-1.pdf 1970] | 2.92(3)&nbsp;μs | IT | '''''¹³⁶Xe''''' | 6+ | | |-id=Xenon-137 | ¹³⁷Xe | style="text-align:right" | 54 | style="text-align:right" | 83 | 136.91155777(11) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/137.pdf 1943] | 3.818(13)&nbsp;min | β⁻ | ¹³⁷Cs | 7/2− | | |-id=Xenon-138 | ¹³⁸Xe | style="text-align:right" | 54 | style="text-align:right" | 84 | 137.9141463(30) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/138.pdf 1943] | 14.14(7)&nbsp;min | β⁻ | ¹³⁸Cs | 0+ | | |-id=Xenon-139 | ¹³⁹Xe | style="text-align:right" | 54 | style="text-align:right" | 85 | 138.9187922(23) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/139.pdf 1951] | 39.68(14)&nbsp;s | β⁻ | ¹³⁹Cs | 3/2− | | |-id=Xenon-140 | ¹⁴⁰Xe | style="text-align:right" | 54 | style="text-align:right" | 86 | 139.9216458(25) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/140.pdf 1951] | 13.60(10)&nbsp;s | β⁻ | ¹⁴⁰Cs | 0+ | | |-id=Xenon-141 | rowspan=2|¹⁴¹Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 87 | rowspan=2|140.9267872(31) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/141.pdf 1951] | rowspan=2|1.73(1)&nbsp;s | β⁻ (99.96%) | ¹⁴¹Cs | rowspan=2|5/2− | rowspan=2| | rowspan=2| |- | β⁻, n (0.044%) | ¹⁴⁰Cs |-id=Xenon-142 | rowspan=2|¹⁴²Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 88 | rowspan=2|141.9299731(29) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/142.pdf 1960] | rowspan=2|1.23(2)&nbsp;s | β⁻ (99.63%) | ¹⁴²Cs | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (0.37%) | ¹⁴¹Cs |-id=Xenon-143 | rowspan=2|¹⁴³Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 89 | rowspan=2|142.9353696(50) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/143.pdf 1951] | rowspan=2|511(6)&nbsp;ms | β⁻ (99.00%) | ¹⁴³Cs | rowspan=2|5/2− | rowspan=2| | rowspan=2| |- | β⁻, n (1.00%) | ¹⁴²Cs |-id=Xenon-144 | rowspan=2|¹⁴⁴Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 90 | rowspan=2|143.9389451(57) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/144.pdf 1989] | rowspan=2|0.388(7)&nbsp;s | β⁻ (97.0%) | ¹⁴⁴Cs | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (3.0%) | ¹⁴³Cs |-id=Xenon-145 | rowspan=2|¹⁴⁵Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 91 | rowspan=2|144.944720(12) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/145.pdf 2003] | rowspan=2|188(4)&nbsp;ms | β⁻ (95.0%) | ¹⁴⁵Cs | rowspan=2|3/2−# | rowspan=2| | rowspan=2| |- | β⁻, n (5.0%) | ¹⁴⁴Cs |-id=Xenon-146 | rowspan=2|¹⁴⁶Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 92 | rowspan=2|145.948518(26) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/146.pdf 1989] | rowspan=2|146(6)&nbsp;ms | β⁻ | ¹⁴⁶Cs | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (6.9%) | ¹⁴⁵Cs |-id=Xenon-147 | rowspan=2|¹⁴⁷Xe | rowspan=2 style="text-align:right" | 54 | rowspan=2 style="text-align:right" | 93 | rowspan=2|146.95448(22)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/147.pdf 1994] | rowspan=2|88(14)&nbsp;ms | β⁻ (>92%) | ¹⁴⁷Cs | rowspan=2|3/2−# | rowspan=2| | rowspan=2| |- | β⁻, n (<8%) | ¹⁴⁶Cs |-id=Xenon-148 | ¹⁴⁸Xe | style="text-align:right" | 54 | style="text-align:right" | 94 | 147.95851(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/148.pdf 2010] | 85(15)&nbsp;ms | β⁻ | ¹⁴⁸Cs | 0+ | | |-id=Xenon-149 | ¹⁴⁹Xe | style="text-align:right" | 54 | style="text-align:right" | 95 | 148.96457(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/149.pdf 2018] | 50#&nbsp;ms<br />[>550&nbsp;ms] | | | 3/2−# | | |-id=Xenon-150 | ¹⁵⁰Xe | style="text-align:right" | 54 | style="text-align:right" | 96 | 149.96888(32)# | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/54/150.pdf 2018] | 40#&nbsp;ms<br />[>550&nbsp;ns] | | | 0+ | | {{Isotopes table/footer}}

==Xenon-124== Xenon-124 is an isotope of xenon that undergoes double electron capture to tellurium-124 with a very long half-life of {{val|1.1|e=22}} years, approximately 12 orders of magnitude longer than the age of the universe. This decay was observed in the XENON1T detector in 2019, and is the slowest one ever directly observed.<ref>{{cite web |title=A Dark Matter Detector Just Recorded One of The Rarest Events Known to Science |url=https://www.sciencealert.com/a-dark-matter-detector-just-detected-one-of-the-rarest-events-ever-in-science |author=David Nield |date=26 Apr 2019}}</ref> (Even slower decays of other nuclei have been measured, but by detecting decay products that have accumulated over billions of years rather than observing them directly.)<ref>{{cite journal |author1=Hennecke, Edward W. |author2=Manuel, O. K. |author3=Sabu, Dwarka D. |title=Double beta decay of Te 128 |journal=Physical Review C |volume=11 |issue=4 |date=1975 |pages=1378–1384 |doi=10.1103/PhysRevC.11.1378 |url=http://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=2240&context=chem_facwork|url-access=subscription }}</ref>

== Xenon-129 == [[File:MRI with inhaled Xe-129 shows improved ventilation over time.jpg|thumb|MRI with inhaled ¹²⁹Xe shows improved ventilation over<ref>{{cite web | title=Xenon-129 | url=https://pubchem.ncbi.nlm.nih.gov/compound/Xenon-129 }}</ref> time. H (grayscale) + ¹²⁹Xe MRI (cyan) slices at day 0, day 28, 1-y and 2.5-y follow-up, Anti-IL-5Rα (benralizumab)-treated Eosinophilic Asthma]]

'''Xenon-129''' is a stable nuclide that is inhaled to assess pulmonary function, and to image the lungs by xenon NMR (see image).

== Xenon-133 == '''Xenon-133''' is a radioisotope of xenon, beta decaying to stable caesium-133 with half-life 5.2474 days. Sold as a drug under the brand name ''Xeneisol'', (ATC code {{ATC|V09|EX03}}) it is inhaled to assess pulmonary function, and to image the lungs.<ref>{{Cite journal | last1 = Jones | first1 = R. L. | last2 = Sproule | first2 = B. J. | last3 = Overton | first3 = T. R. | title = Measurement of regional ventilation and lung perfusion with Xe-133 | journal = Journal of Nuclear Medicine | volume = 19 | issue = 10 | pages = 1187–1188 | year = 1978 | pmid = 722337 }}</ref> It is also used to image blood flow, particularly in the brain.<ref>{{Cite journal | last1 = Hoshi | first1 = H. | last2 = Jinnouchi | first2 = S. | last3 = Watanabe | first3 = K. | last4 = Onishi | first4 = T. | last5 = Uwada | first5 = O. | last6 = Nakano | first6 = S. | last7 = Kinoshita | first7 = K. | title = Cerebral blood flow imaging in patients with brain tumor and arterio-venous malformation using Tc-99m hexamethylpropylene-amine oxime--a comparison with Xe-133 and IMP | journal = Kaku Igaku | volume = 24 | issue = 11 | pages = 1617–1623 | year = 1987 | pmid = 3502279 }}</ref> ¹³³Xe is a fission product produced by fission of uranium-235.<ref>{{cite journal |last1=Tachimori |first1=Syoichi |last2=Amano |first2=Hiroshi |title=Preliminary Study on Production of Xenon-133 from Neutron-Irradiated Uranium Metal and Oxides by Oxidation |journal=Journal of NUCLEAR SCIENCE and TECHNOLOGY |date=November 1974 |volume=11 |issue=11 |pages=488–494 |doi=10.1080/18811248.1974.9730699 |bibcode=1974JNST...11..488T |doi-access=free }}</ref> It is discharged to the atmosphere in small quantities by some nuclear power plants.<ref name=":0">{{Cite book |url=https://www.ncbi.nlm.nih.gov/books/NBK201991/ |title=Effluent Releases from Nuclear Power Plants and Fuel-Cycle Facilities |date=2012-03-29 |publisher=National Academies Press (US) |language=en }}</ref>

==Xenon-135== {{main|Xenon-135}}

'''Xenon-135''' is a radioactive isotope of xenon, produced as a fission product of uranium. It has a half-life of 9.14 hours and is the most powerful known neutron-absorbing nuclear poison (having a neutron absorption cross-section of about 2 million barns<ref>{{Cite web|url=https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html|title = Livechart - Table of Nuclides - Nuclear structure and decay data}}</ref>). The overall yield of xenon-135 from fission is 6.3%, without considering any loss by neutron capture. ¹³⁵Xe exerts a significant effect on nuclear reactor operation (xenon pit). It is discharged to the atmosphere in small quantities by some nuclear power plants.<ref name=":0" />

==Xenon-136== Xenon-136 is an isotope of xenon that undergoes double beta decay to barium-136 with a very long half-life of {{val|2.18|e=21}} years, approximately 11 orders of magnitude longer than the age of the universe. It is being used in the Enriched Xenon Observatory experiment to search for neutrinoless double beta decay.

== See also ==

* Xenon isotope geochemistry

'''Daughter products other than xenon''' * Isotopes of caesium * Isotopes of iodine * Isotopes of tellurium * Isotopes of antimony

==References== {{Reflist}}

{{Navbox element isotopes}}

Category:Isotopes of xenon Category:Xenon Xenon