Isotopes of krypton

{{Short description|none}} {{Infobox krypton isotopes}} There are 34 known isotopes of krypton (₃₆Kr) with atomic mass numbers from 67 to 103. Naturally occurring krypton is made of five stable isotopes and one ({{SimpleNuclide|krypton|78}}) which is slightly radioactive with an extremely long half-life, plus traces of radioisotopes that are produced by cosmic rays in the atmosphere. Atmospheric krypton today is, however, considerably radioactive due almost entirely to artificial ⁸⁵Kr.<ref>{{cite journal | last1=Turkevich | first1=Anthony | last2=Winsberg | first2=Lester | last3=Flotow | first3=Howard | last4=Adams | first4=Richard M. | title=The radioactivity of atmospheric krypton in 1949–1950 | journal=Proceedings of the National Academy of Sciences | date=1997 | volume=94 | issue=15 | pages=7807–7810 | doi=10.1073/pnas.94.15.7807 | doi-access=free | pmid=11607731 | pmc=33711 | bibcode=1997PNAS...94.7807T }}</ref>

== List of isotopes == {{Isotopes table | symbol = Kr | refs = NUBASE2020, AME2020 II, IsotopeFRIB, IsomerFRIB | notes = m, unc(), mass#, hl#, hl-nst, spin(), spin#, daughter-st, daughter-nst, n, discoveryname }} |-id=Krypton-67 | rowspan=2|⁶⁷Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 31 | rowspan=2|66.98331(46)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/67.pdf 2016] | rowspan=2|7.4(29)&nbsp;ms | β⁺? (63%) | ⁶⁷Br | rowspan=2|3/2-# | rowspan=2| | rowspan=2| |- |2p (37%) |⁶⁵Se |-id=Krypton-68 | rowspan=3|⁶⁸Kr | rowspan=3 style="text-align:right" | 36 | rowspan=3 style="text-align:right" | 32 | rowspan=3|67.97249(54)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/68.pdf 2016] | rowspan=3|21.6(33)&nbsp;ms | β⁺, p (>90%) | ⁶⁷Se | rowspan=3|0+ | rowspan=3| | rowspan=3| |- |β⁺? (<10%) |⁶⁸Br |- |p? |⁶⁷Br |-id=Krypton-69 | rowspan=2|⁶⁹Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 33 | rowspan=2|68.96550(32)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/69.pdf 1995] | rowspan=2|27.9(8)&nbsp;ms | β⁺, p (94%) | ⁶⁸Se | rowspan=2|(5/2−) | rowspan=2| | rowspan=2| |- | β⁺ (6%) | ⁶⁹Br |-id=Krypton-70 | rowspan=2|⁷⁰Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 34 | rowspan=2|69.95588(22)# | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/70.pdf 1995] | rowspan=2|45.00(14)&nbsp;ms | β⁺ (>98.7%) | ⁷⁰Br | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺, p (<1.3%) | ⁶⁹Se |-id=Krypton-71 | rowspan=2|⁷¹Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 35 | rowspan=2|70.95027(14) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/71.pdf 1981] | rowspan=2|98.8(3)&nbsp;ms | β⁺ (97.9%) | ⁷¹Br | rowspan=2|(5/2)− | rowspan=2| | rowspan=2| |- | β⁺, p (2.1%) | ⁷⁰Se |-id=Krypton-72 | ⁷²Kr | style="text-align:right" | 36 | style="text-align:right" | 36 | 71.9420924(86) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/72.pdf 1973] | 17.16(18)&nbsp;s | β⁺ | ⁷²Br | 0+ | | |-id=Krypton-73 | rowspan=2|⁷³Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 37 | rowspan=2|72.9392892(71) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/73.pdf 1972] | rowspan=2|27.3(10)&nbsp;s | β⁺ (99.75%) | ⁷³Br | rowspan=2|(3/2)− | rowspan=2| | rowspan=2| |- | β⁺, p (0.25%) | ⁷²Se |-id=Krypton-73m | style="text-indent:1em" | ^73mKr | colspan="3" style="text-indent:2em" | 433.55(13)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/73Kr-1.pdf 1993] | 107(10)&nbsp;ns | IT | ⁷³Kr | (9/2+) | | |-id=Krypton-74 | ⁷⁴Kr | style="text-align:right" | 36 | style="text-align:right" | 38 | 73.9330840(22) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/74.pdf 1960] | 11.50(11)&nbsp;min | β⁺ | ⁷⁴Br | 0+ | | |-id=Krypton-75 | ⁷⁵Kr | style="text-align:right" | 36 | style="text-align:right" | 39 | 74.9309457(87) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/75.pdf 1960] | 4.60(7)&nbsp;min | β⁺ | ⁷⁵Br | 5/2+ | | |-id=Krypton-76 | ⁷⁶Kr | style="text-align:right" | 36 | style="text-align:right" | 40 | 75.9259107(43) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/76.pdf 1954] | 14.8(1)&nbsp;h | β⁺ | ⁷⁶Br | 0+ | | |-id=Krypton-77 | ⁷⁷Kr | style="text-align:right" | 36 | style="text-align:right" | 41 | 76.9246700(21) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/77.pdf 1948] | 72.6(9)&nbsp;min | β⁺ | ⁷⁷Br | 5/2+ | | |-id=Krypton-77m | style="text-indent:1em" | ^77mKr | colspan="3" style="text-indent:2em" | 66.50(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/77Kr-1.pdf 1975] | 118(12)&nbsp;ns | IT | ⁷⁷Kr | 3/2− | | |-id=Krypton-78 | ⁷⁸Kr<ref group="n">Primordial radionuclide</ref> | style="text-align:right" | 36 | style="text-align:right" | 42 | 77.92036634(33) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/78.pdf 1920] | align=center|'''9.2 {{±|5.5|2.6}} {{±|1.3}}{{e|21}} y'''<ref name="Patrignani2016" /> |Double EC |'''⁷⁸Se''' | 0+ | 0.00355(3) | |-id=Krypton-79 | ⁷⁹Kr | style="text-align:right" | 36 | style="text-align:right" | 43 | 78.9200829(37) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/79.pdf 1948] | 35.04(10)&nbsp;h | β⁺ | '''⁷⁹Br''' | 1/2− | | |-id=Krypton-79m | style="text-indent:1em" | ^79mKr | colspan="3" style="text-indent:2em" | 129.77(5)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/79Kr-1.pdf 1969] | 50(3)&nbsp;s | IT | ⁷⁹Kr | 7/2+ | | |-id=Krypton-80 | ⁸⁰Kr | style="text-align:right" | 36 | style="text-align:right" | 44 | 79.91637794(75) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/80.pdf 1920] | colspan=3 align=center|'''Stable''' | 0+ | 0.02286(10) | |-id=Krypton-81m | ⁸¹Kr<ref group="n">Used to date groundwater</ref> | style="text-align:right" | 36 | style="text-align:right" | 45 | 80.9165897(12) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/81.pdf 1950] | 2.29(11)×10⁵&nbsp;y | EC | '''⁸¹Br''' | 7/2+ | {{val|6e-13}}<ref name="zheng-tian">{{cite journal |last1=Lu |first1=Zheng-Tian |title=What trapped atoms reveal about global groundwater |journal=Physics Today |date=1 March 2013 |volume=66 |issue=3 |pages=74–75 |doi=10.1063/PT.3.1926 |bibcode=2013PhT....66c..74L |url=https://pubs.aip.org/physicstoday/article/66/3/74/414350/What-trapped-atoms-reveal-about-global |access-date=29 June 2024}}</ref> | |-id=Krypton-81m | rowspan=2 style="text-indent:1em" | ^81mKr | rowspan=2 colspan="3" style="text-indent:2em" | 190.64(4)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/81Kr-1.pdf 1969] | rowspan=2|13.10(3)&nbsp;s | IT | ⁸¹Kr | rowspan=2|1/2− | rowspan=2| | rowspan=2| |- | EC (0.0025%) | '''⁸¹Br''' |-id=Krypton-82 | ⁸²Kr | style="text-align:right" | 36 | style="text-align:right" | 46 | 81.9134811537(59) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/82.pdf 1920] | colspan=3 align=center|'''Stable''' | 0+ | 0.11593(31) | |-id=Krypton-83 | ⁸³Kr<ref group="n" name="FP">Fission product</ref> | style="text-align:right" | 36 | style="text-align:right" | 47 | 82.914126516(9) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/83.pdf 1920] | colspan=3 align=center|'''Stable''' | 9/2+ | 0.11500(19) | |-id=Krypton-83m1 | style="text-indent:1em" | ^83m1Kr | colspan="3" style="text-indent:2em" | 9.4053(8)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/83Kr-2.pdf 1963] | 156.8(5)&nbsp;ns | IT | '''⁸³Kr''' | 7/2+ | | |-id=Krypton-83m2 | style="text-indent:1em" | ^83m2Kr | colspan="3" style="text-indent:2em" | 41.5575(7)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/83Kr-1.pdf 1940] | 1.830(13)&nbsp;h | IT | '''⁸³Kr''' | 1/2− | | |-id=Krypton-84 | ⁸⁴Kr<ref group="n" name="FP" /> | style="text-align:right" | 36 | style="text-align:right" | 48 | 83.9114977271(41) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/84.pdf 1920] | colspan=3 align=center|'''Stable''' | 0+ | 0.56987(15) | |-id=Krypton-84m | style="text-indent:1em" | ^84mKr | colspan="3" style="text-indent:2em" | 3236.07(18)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/84Kr-1.pdf 1977] | 1.83(4)&nbsp;μs | IT | '''⁸⁴Kr''' | 8+ | | |-id=Krypton-85 | ⁸⁵Kr<ref group="n" name="FP" /> | style="text-align:right" | 36 | style="text-align:right" | 49 | 84.9125273(21) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/85.pdf 1943] | 10.728(7)&nbsp;y | β⁻ | '''⁸⁵Rb''' | 9/2+ | {{val|1e-11}}<ref name="zheng-tian"/> | |-id=Krypton-85m1 | rowspan=2 style="text-indent:1em" | ^85m1Kr<ref group="n" name="FP" /> | rowspan=2 colspan="3" style="text-indent:2em" | 304.871(20)&nbsp;keV | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/85Kr-1.pdf 1947] | rowspan=2|4.480(8)&nbsp;h | β⁻ (78.8%) | '''⁸⁵Rb''' | rowspan=2|1/2− | rowspan=2| | rowspan=2| |- | IT (21.2%) | ⁸⁵Kr |-id=Krypton-85m2 | style="text-indent:1em" | ^85m2Kr | colspan="3" style="text-indent:2em" | 1991.8(2)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/85Kr-2.pdf 1989] | 1.82(5)&nbsp;μs<br/> | IT | ⁸⁵Kr | (17/2+) | | |-id=Krypton-86 | ⁸⁶Kr<ref group="n">Formerly used to define the meter</ref><ref group="n" name="FP" /> | style="text-align:right" | 36 | style="text-align:right" | 50 | 85.9106106247(40) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/86.pdf 1920] | colspan=3 align=center|'''Observationally Stable'''<ref group="n">Believed to decay by β⁻β⁻ to '''⁸⁶Sr'''</ref> | 0+ | 0.17279(41) | |-id=Krypton-87 | ⁸⁷Kr | style="text-align:right" | 36 | style="text-align:right" | 51 | 86.91335476(26) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/87.pdf 1943] | 76.3(5)&nbsp;min | β⁻ | '''''⁸⁷Rb''''' | 5/2+ | | |-id=Krypton-88 | ⁸⁸Kr | style="text-align:right" | 36 | style="text-align:right" | 52 | 87.9144479(28) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/88.pdf 1939] | 2.825(19)&nbsp;h | β⁻ | ⁸⁸Rb | 0+ | | |-id=Krypton-89 | ⁸⁹Kr | style="text-align:right" | 36 | style="text-align:right" | 53 | 88.9178354(23) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/89.pdf 1943] | 3.15(4)&nbsp;min | β⁻ | ⁸⁹Rb | 3/2+ | | |-id=Krypton-90 | ⁹⁰Kr | style="text-align:right" | 36 | style="text-align:right" | 54 | 89.9195279(20) | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/90.pdf 1951] | 32.32(9)&nbsp;s | β⁻ | ^90mRb | 0+ | | |-id=Krypton-91 | rowspan=2|⁹¹Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 55 | rowspan=2|90.9238063(24) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/91.pdf 1951] | rowspan=2|8.57(4)&nbsp;s | β⁻ | ⁹¹Rb | rowspan=2|5/2+ | rowspan=2| | rowspan=2| |- | β⁻, n? | ⁹⁰Rb |-id=Krypton-92 | rowspan=2|⁹²Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 56 | rowspan=2|91.9261731(29) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/92.pdf 1951] | rowspan=2|1.840(8)&nbsp;s | β⁻ (99.97%) | ⁹²Rb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (0.0332%) | ⁹¹Rb |-id=Krypton-93 | rowspan=2|⁹³Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 57 | rowspan=2|92.9311472(27) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/93.pdf 1951] | rowspan=2|1.287(10)&nbsp;s | β⁻ (98.05%) | ⁹³Rb | rowspan=2|1/2+ | rowspan=2| | rowspan=2| |- | β⁻, n (1.95%) | ⁹²Rb |-id=Krypton-94 | rowspan=2|⁹⁴Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 58 | rowspan=2|93.934140(13) | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/94.pdf 1972] | rowspan=2|212(4)&nbsp;ms | β⁻ (98.89%) | ⁹⁴Rb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (1.11%) | ⁹³Rb |-id=Krypton-95 | rowspan=3|⁹⁵Kr | rowspan=3 style="text-align:right" | 36 | rowspan=3 style="text-align:right" | 59 | rowspan=3|94.939711(20) | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/95.pdf 1994] | rowspan=3|114(3)&nbsp;ms | β⁻ (97.13%) | ⁹⁵Rb | rowspan=3|1/2+ | rowspan=3| | rowspan=3| |- | β⁻, n (2.87%) | ⁹⁴Rb |- | β⁻, 2n? | ⁹³Rb |-id=Krypton-95m | style="text-indent:1em" | ^95mKr | colspan="3" style="text-indent:2em" | 195.5(3)&nbsp;keV | style="text-align:center" | [https://www.nndc.bnl.gov/discovery/isomers/abstracts/36/95Kr-1.pdf 2006] | 1.582(22)&nbsp;μs<br/> | IT | ⁹⁵Kr | (7/2+) | | |-id=Krypton-96 | rowspan=2|⁹⁶Kr | rowspan=2 style="text-align:right" | 36 | rowspan=2 style="text-align:right" | 60 | rowspan=2|95.942998(62)<ref>{{Cite journal|url=https://link.springer.com/article/10.1007/s10751-020-01722-2|doi = 10.1007/s10751-020-01722-2|title = High-precision mass measurement of neutron-rich 96Kr|year = 2020|last1 = Smith|first1 = Matthew B.|last2 = Murböck|first2 = Tobias|last3 = Dunling|first3 = Eleanor|last4 = Jacobs|first4 = Andrew|last5 = Kootte|first5 = Brian|last6 = Lan|first6 = Yang|last7 = Leistenschneider|first7 = Erich|last8 = Lunney|first8 = David|last9 = Lykiardopoulou|first9 = Eleni Marina|last10 = Mukul|first10 = Ish|last11 = Paul|first11 = Stefan F.|last12 = Reiter|first12 = Moritz P.|last13 = Will|first13 = Christian|last14 = Dilling|first14 = Jens|last15 = Kwiatkowski|first15 = Anna A.|journal = Hyperfine Interactions|volume = 241| issue=1 | page=59 | bibcode=2020HyInt.241...59S |s2cid = 220512482}}</ref> | rowspan=2 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/96.pdf 1994] | rowspan=2|80(8)&nbsp;ms | β⁻ (96.3%) | ⁹⁶Rb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁻, n (3.7%) | ⁹⁵Rb |-id=Krypton-97 | rowspan=3|⁹⁷Kr | rowspan=3 style="text-align:right" | 36 | rowspan=3 style="text-align:right" | 61 | rowspan=3|96.94909(14) | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/97.pdf 1997] | rowspan=3|62.2(32)&nbsp;ms | β⁻ (93.3%) | ⁹⁷Rb | rowspan=3|3/2+# | rowspan=3| | rowspan=3| |- | β⁻, n (6.7%) | ⁹⁶Rb |- | β⁻, 2n? | ⁹⁵Rb |-id=Krypton-98 | rowspan=3|⁹⁸Kr | rowspan=3 style="text-align:right" | 36 | rowspan=3 style="text-align:right" | 62 | rowspan=3|97.95264(32)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/98.pdf 1997] | rowspan=3|42.8(36)&nbsp;ms | β⁻ (93.0%) | ⁹⁸Rb | rowspan=3|0+ | rowspan=3| | rowspan=3| |- | β⁻, n (7.0%) | ⁹⁷Rb |- | β⁻, 2n? | ⁹⁶Rb |-id=Krypton-99 | rowspan=3|⁹⁹Kr | rowspan=3 style="text-align:right" | 36 | rowspan=3 style="text-align:right" | 63 | rowspan=3|98.95878(43)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/99.pdf 1997] | rowspan=3|40(11)&nbsp;ms | β⁻ (89%) | ⁹⁹Rb | rowspan=3|5/2−# | rowspan=3| | rowspan=3| |- | β⁻, n (11%) | ⁹⁸Rb |- | β⁻, 2n? | ⁹⁷Rb |-id=Krypton-100 | rowspan=3|¹⁰⁰Kr | rowspan=3 style="text-align:right" | 36 | rowspan=3 style="text-align:right" | 64 | rowspan=3|99.96300(43)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/100.pdf 1997] | rowspan=3|12(8)&nbsp;ms | β⁻ | ¹⁰⁰Rb | rowspan=3|0+ | rowspan=3| | rowspan=3| |- | β⁻, n? | ⁹⁹Rb |- | β⁻, 2n? | ⁹⁸Rb |-id=Krypton-101 | rowspan=3 | ¹⁰¹Kr | rowspan=3 | 36 | rowspan=3 | 65 | rowspan=3 | 100.96932(54)# | rowspan=3 style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/101.pdf 2010] | rowspan=3 | 9#&nbsp;ms<br />[>400&nbsp;ns] | β⁻? | ¹⁰¹Rb | rowspan=3 | 5/2+# | rowspan=3 | | rowspan=3 | |- | β⁻, n? | ¹⁰⁰Rb |- | β⁻, 2n? | ⁹⁹Rb |-id=Krypton-102 | ¹⁰²Kr<ref name="101Br-aps">{{Cite journal|url=https://journals.aps.org/prc/abstract/10.1103/PhysRevC.103.014614|doi = 10.1103/PhysRevC.103.014614|title = Observation of new neutron-rich isotopes in the vicinity of Zr110|year = 2021|last1 = Sumikama|first1 = T.|last2 = Fukuda|first2 = N.|last3 = Inabe|first3 = N.|last4 = Kameda|first4 = D.|last5 = Kubo|first5 = T.|last6 = Shimizu|first6 = Y.|last7 = Suzuki|first7 = H.|last8 = Takeda|first8 = H.|last9 = Yoshida|first9 = K.|last10 = Baba|first10 = H.|last11 = Browne|first11 = F.|last12 = Bruce|first12 = A. M.|last13 = Carroll|first13 = R.|last14 = Chiga|first14 = N.|last15 = Daido|first15 = R.|last16 = Didierjean|first16 = F.|last17 = Doornenbal|first17 = P.|last18 = Fang|first18 = Y.|last19 = Gey|first19 = G.|last20 = Ideguchi|first20 = E.|last21 = Isobe|first21 = T.|last22 = Lalkovski|first22 = S.|last23 = Li|first23 = Z.|last24 = Lorusso|first24 = G.|last25 = Lozeva|first25 = R.|last26 = Nishibata|first26 = H.|last27 = Nishimura|first27 = S.|last28 = Nishizuka|first28 = I.|last29 = Odahara|first29 = A.|last30 = Patel|first30 = Z.|journal = Physical Review C|volume = 103| issue=1 | article-number=014614 | bibcode=2021PhRvC.103a4614S |s2cid = 234019083|display-authors = 1|hdl = 10261/260248|hdl-access = free}}</ref> | style="text-align:right" | 36 | style="text-align:right" | 66 | |style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/102.pdf 2021] | | | | 0+ | | |-id=Krypton-103 | ¹⁰³Kr<ref>{{cite journal |last1=Shimizu |first1=Y. |last2=Kubo |first2=T. |last3=Sumikama |first3=T. |last4=Fukuda |first4=N. |last5=Takeda |first5=H. |last6=Suzuki |first6=H. |last7=Ahn |first7=D. S. |last8=Inabe |first8=N. |last9=Kusaka |first9=K. |last10=Ohtake |first10=M. |last11=Yanagisawa |first11=Y. |last12=Yoshida |first12=K. |last13=Ichikawa |first13=Y. |last14=Isobe |first14=T. |last15=Otsu |first15=H. |last16=Sato |first16=H. |last17=Sonoda |first17=T. |last18=Murai |first18=D. |last19=Iwasa |first19=N. |last20=Imai |first20=N. |last21=Hirayama |first21=Y. |last22=Jeong |first22=S. C. |last23=Kimura |first23=S. |last24=Miyatake |first24=H. |last25=Mukai |first25=M. |last26=Kim |first26=D. G. |last27=Kim |first27=E. |last28=Yagi |first28=A. |title=Production of new neutron-rich isotopes near the N = 60 isotones Ge 92 and As 93 by in-flight fission of a 345 MeV/nucleon U 238 beam |journal=Physical Review C |date=8 April 2024 |volume=109 |issue=4 |article-number=044313 |doi=10.1103/PhysRevC.109.044313 }}</ref> | style="text-align:right" | 36 | style="text-align:right" | 67 | |style="text-align:center" | [https://www.nndc.bnl.gov/discovery/abstracts/36/103.pdf 2024] | | | | | | {{Isotopes table/footer}}

== Notable isotopes == {{more citations needed section|date=May 2018}}

=== Krypton-81 === {{Expand section|1=Usage in hydrogeology, ATC=V09|date=October 2019}} Krypton-81 (half-life 230,000 years) is useful in determining how old the water beneath the ground is. Radioactive krypton-81 is the product of spallation reactions with cosmic rays striking gases present in the Earth atmosphere, along with the six stable or nearly stable krypton isotopes.<ref name="cosmo">{{cite journal|last1=Leya|first1=I. |last2=Gilabert|first2=E. |last3=Lavielle|first3=B. |last4=Wiechert|first4=U. |last5=Wieler|first5=W. |date=2004 |title=Production rates for cosmogenic krypton and argon isotopes in H-chondrites with known ³⁶Cl-³⁶Ar ages |journal=Antarctic Meteorite Research |volume=17 |pages=185–199 |bibcode=2004AMR....17..185L |url=https://core.ac.uk/download/pdf/51485498.pdf}}</ref> The long half-life ensures that the isotope has a uniform concentration in the atmosphere and in surface water; when the water goes underground is supply is no longer replenished and decays, allowing dating of the residence time in deep aquifers in a range of 20,000 to a million years, bridging the gap where other isotopic methods (e.g. carbon-14 dating) lose sensitivity. The same long half-life renders detection of its decay impossible and, therefore, demands some form of mass spectrometry. Even so, technical limitations of the method have traditionally required the sampling of very large volumes of water: several hundred liters or a few cubic meters of water (about a milligram of krypton). This is particularly challenging for dating pore water in deep clay aquitards with very low hydraulic conductivity.<ref> {{cite report |first=N. |last=Thonnard |first2=L. D.|last2= MeKay |first3=T. C.|last3= Labotka |year=2001 |title=Development of Laser-Based Resonance Ionization Techniques for 81-Kr and 85-Kr Measurements in the Geosciences |url=https://digital.library.unt.edu/ark:/67531/metadc737461/m2/1/high_res_d/809813.pdf |pages=4–7 |publisher=University of Tennessee, Institute for Rare Isotope Measurements |doi=10.2172/809813 |osti=809813 }}</ref> More recently, it has been announced<ref>{{Cite journal |last=Le-Yi Tu, Guo-Min Yang, Cun-Feng Cheng, Gu-Liang Liu, Xiang-Yang Zhang, and Shui-Ming Hu |date=2014 |title=Analysis of Krypton-85 and Krypton-81 in a Few Liters of Air |url=http://staff.ustc.edu.cn/~smhu/publication/AC2014Tu.pdf |journal=Analytical Chemistry |volume=86 |issue=8 |pages=4002–4007 |doi= 10.1021/ac500415a|pmid= 24641193|bibcode= 2014AnaCh..86.4002T|via=}}</ref> that samples an order of magnitude less can be used successfully.

Because cosmic ray production in the atmosphere creates a globally fairly uniform ⁸¹Kr/Kr concentration, one can assume a known initial ratio in meteoric water before recharge. There are essentially no significant anthropogenic or in situ geological sources (in typical crustal settings) that would confound the decay clock, making krypton-81 a relatively "clean" choice for geological dating.{{citation needed|date=October 2025}}

The short-lived isomer krypton-81m (half-life 13 seconds) has medical uses but is often considered impractical for use as it must be generated from the rare rubidium-81.<ref>{{Cite book |last1=Watson |first1=I. A. |chapter-url=https://link.springer.com/10.1007/978-94-009-4297-4_3 |chapter=Pharmaceutical Aspects of Krypton-81m Generators |last2=Waters |first2=S. L. |date=1986 |title=Progress in Radiopharmacy |publisher=Springer Netherlands |isbn=978-94-010-8410-9 |editor-last=Cox |editor-first=P. H. |place=Dordrecht |pages=32–45 |language=en |doi=10.1007/978-94-009-4297-4_3 |access-date=2025-10-15 |editor2-last=Mather |editor2-first=S. J. |editor3-last=Sampson |editor3-first=C. B. |editor4-last=Lazarus |editor4-first=C. R.}}</ref> It almost entirely decays to the ground state with a monochromatic gamma ray.

=== Krypton-85 === {{Main|Krypton-85}} Krypton-85 (half-life 10.728 years) is produced by the nuclear fission of uranium and plutonium in nuclear weapons testing and in nuclear reactors, as well as by cosmic rays. An important goal of the Limited Nuclear Test Ban Treaty of 1963 was to eliminate the release of such radioisotopes into the atmosphere, and since 1963 much of that krypton-85 has had time to decay. However, it is almost inevitable that krypton-85 is released during the reprocessing of fuel rods from nuclear reactors,<ref>{{cite web | title=Separation, Storage and Disposal of Krypton-85 | url=https://inis.iaea.org/collection/NCLCollectionStore/_Public/11/569/11569296.pdf | access-date=2024-12-08 | page=8 }}</ref> which is far larger-volume than was ever nuclear testing.

==== Atmospheric concentration ==== {{see also|Nuclear reprocessing}}

The atmospheric concentration of krypton-85 around the North Pole is about 30 percent higher than that at the South Pole because nearly all of the world's nuclear reactors and all of its major nuclear reprocessing plants are located in the Northern Hemisphere, well north of the equator<ref>{{cite web |title=Resources on Isotopes |url=https://wwwrcamnl.wr.usgs.gov/isoig/period/kr_iig.html |archive-url=https://web.archive.org/web/20010924204348/http://wwwrcamnl.wr.usgs.gov/isoig/period/kr_iig.html |archive-date=2001-09-24 |publisher=U.S. Geological Survey |access-date=2007-03-20 }}</ref> and transfer of air between the hemispheres is slow.

The nuclear reprocessing plants with significant capacities are located in the United States, the United Kingdom, the French Republic, the Russian Federation, Mainland China (PRC), Japan, India, and Pakistan.

=== Krypton-86 ===

Krypton-86 was formerly used to define the meter from 1960 until 1983, when the definition of the meter was based on the wavelength of the 606&nbsp;nm (orange) spectral line of a krypton-86 atom.<ref>{{cite journal | title=The International Length Standard | first1=K. M. | last1=Baird | first2=L. E. | last2=Howlett | journal=Applied Optics | volume=2 | issue=5 | pages=455–463 | year=1963 | doi=10.1364/AO.2.000455| bibcode=1963ApOpt...2..455B }}</ref>

== See also == '''Daughter products other than krypton''' * Isotopes of rubidium * Isotopes of bromine * Isotopes of selenium

==References== {{reflist}}

==External links== * [http://www.nndc.bnl.gov/chart/reCenter.jsp?z=36&n=65 Brookhaven National Laboratory: Krypton-101 information] {{Webarchive|url=https://web.archive.org/web/20171018072258/http://www.nndc.bnl.gov/chart/reCenter.jsp?z=36&n=65 |date=2017-10-18 }}

{{Navbox element isotopes}}

Category:Isotopes of krypton Category:Krypton Krypton