Isotopes of selenium#Selenium-82

Selenium has six natural isotopes that occur in significant quantities, along with the trace isotope ⁷⁹Se, which occurs in minute quantities in uranium ores. Five of these isotopes are stable: ⁷⁴Se, ⁷⁶Se, ⁷⁷Se, ⁷⁸Se, and ⁸⁰Se. The last three also occur as fission products, along with ⁷⁹Se, which has a half-life of 327,000 years,[http://www.ptb.de/en/org/6/nachrichten6/2010/60710_en.htm The half-life of ⁷⁹Se] {{webarchive |url=https://web.archive.org/web/20110927042432/http://www.ptb.de/en/org/6/nachrichten6/2010/60710_en.htm |date=September 27, 2011 }}{{cite journal |last1=Jorg |first1=Gerhard |last2=Buhnemann |first2=Rolf |last3=Hollas |first3=Simon |last4=Kivel |first4=Niko |last5=Kossert |first5=Karsten |last6=Van Winckel |first6=Stefaan |last7=Gostomski |first7=Christoph Lierse v. |title=Preparation of radiochemically pure ⁷⁹Se and highly precise determination of its half-life |journal=Applied Radiation and Isotopes |volume=68 |pages=2339–51|year=2010 |doi=10.1016/j.apradiso.2010.05.006 |pmid=20627600 |issue=12}} and ⁸²Se, which has a very long half-life (~10²⁰ years, decaying via double beta decay to ⁸²Kr) and for practical purposes can be considered to be stable. There are 23 other unstable isotopes that have been characterized, the longest-lived being ⁷⁹Se with a half-life 327,000 years, ⁷⁵Se with a half-life of 120 days, and ⁷²Se with a half-life of 8.40 days. Of the other isotopes, ⁷³Se has the longest half-life, 7.15 hours; most others have half-lives not exceeding 38 seconds.

List of isotopes

{{Isotopes table

|symbol=Se

|refs=NUBASE2020, AME2020 II

|notes=m, unc(), mass#, hl#, hl-nst, spin(), spin#, daughter-st, EC, IT, n, p

}}

|-id=Selenium-63

| rowspan=3|⁶³Se

| rowspan=3 style="text-align:right" | 34

| rowspan=3 style="text-align:right" | 29

| rowspan=3|62.98191(54)#

| rowspan=3|13.2(39) ms

| β⁺, p (89%)

| ⁶²Ge

| rowspan=3|3/2−#

| rowspan=3|

| β⁺ (11%)

| ⁶³As

| 2p? (<0.5%)

| ⁶¹Ge

|-id=Selenium-64

| rowspan=2|⁶⁴Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 30

| rowspan=2|63.97117(54)#

| rowspan=2|22.6(2) ms

| β⁺?

| ⁶⁴As

| rowspan=2|0+

| rowspan=2|

| β⁺, p?

| ⁶³Ge

|-id=Selenium-65

| rowspan=2|⁶⁵Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 31

| rowspan=2|64.96455(32)#

| rowspan=2|34.2(7) ms

| β⁺, p (87%)

| ⁶⁴Ge

| rowspan=2|3/2−#

| rowspan=2|

| β⁺ (13%)

| ⁶⁵As

|-id=Selenium-66

| rowspan=2|⁶⁶Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 32

| rowspan=2|65.95528(22)#

| rowspan=2|54(4) ms

| β⁺

| ⁶⁶As

| rowspan=2|0+

| rowspan=2|

| β⁺, p?

| ⁶⁵Ge

|-id=Selenium-67

| rowspan=2|⁶⁷Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 33

| rowspan=2|66.949994(72)

| rowspan=2|133(4) ms

| β⁺ (99.5%)

| ⁶⁷As

| rowspan=2|5/2−#

| rowspan=2|

| β⁺, p (0.5%)

| ⁶⁶Ge

|-id=Selenium-68

| ⁶⁸Se

| style="text-align:right" | 34

| 67.94182524(53)

| 35.5(7) s

| β⁺

| ⁶⁸As

| 0+

|-id=Selenium-69

| rowspan=2|⁶⁹Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 35

| rowspan=2|68.9394148(16)

| rowspan=2|27.4(2) s

| β⁺ (99.95%)

| ⁶⁹As

| rowspan=2|1/2−

| rowspan=2|

| β⁺, p (.052%)

| ⁶⁸Ge

|-id=Selenium-69m1

| style="text-indent:1em" | ^69m1Se

| colspan="3" style="text-indent:2em" | 38.85(22) keV

| 2.0(2) μs

| IT

| ⁶⁹Se

| 5/2−

|-id=Selenium-69m2

| style="text-indent:1em" | ^69m2Se

| colspan="3" style="text-indent:2em" | 574.0(4) keV

| 955(16) ns

| IT

| ⁶⁹Se

| 9/2+

|-id=Selenium-70

| ⁷⁰Se

| style="text-align:right" | 34

| style="text-align:right" | 36

| 69.9335155(17)

| 41.1(3) min

| β⁺

| ⁷⁰As

| 0+

|-id=Selenium-71

| ⁷¹Se

| style="text-align:right" | 34

| style="text-align:right" | 37

| 70.9322094(30)

| 4.74(5) min

| β⁺

| ⁷¹As

| (5/2−)

|-id=Selenium-71m1

| style="text-indent:1em" | ^71m1Se

| colspan="3" style="text-indent:2em" | 48.79(5) keV

| 5.6(7) μs

| IT

| ⁷¹Se

| (1/2−)

|-id=Selenium-71m2

| style="text-indent:1em" | ^71m2Se

| colspan="3" style="text-indent:2em" | 260.48(10) keV

| 19.0(5) μs

| IT

| ⁷¹Se

| (9/2+)

|-id=Selenium-72

| ⁷²Se

| style="text-align:right" | 34

| style="text-align:right" | 38

| 71.9271405(21)

| 8.40(8) d

| EC

| ⁷²As

| 0+

|-id=Selenium-73

| ⁷³Se

| style="text-align:right" | 34

| style="text-align:right" | 39

| 72.9267549(80)

| 7.15(9) h

| β⁺

| ⁷³As

| 9/2+

|-id=Selenium-73m

| rowspan=2 style="text-indent:1em" | ^73mSe

| rowspan=2 colspan="3" style="text-indent:2em" | 25.71(4) keV

| rowspan=2|39.8(17) min

| IT (72.6%)

| ⁷³Se

| rowspan=2|3/2−

| rowspan=2|

| β⁺ (27.4%)

| ⁷³As

|-id=Selenium-74

| ⁷⁴Se

| style="text-align:right" | 34

| style="text-align:right" | 40

| 73.922475933(15)

| colspan=3 align=center|Observationally StableBelieved to decay by β⁺β⁺ to ⁷⁴Ge with a half-life over {{val|2.3e18|u=y}}.

| 0+

| 0.0086(3)

|-id=Selenium-75

| ⁷⁵Se

| style="text-align:right" | 34

| style="text-align:right" | 41

| 74.922522870(78)

| 119.78(3) d

| EC

| ⁷⁵As

| 5/2+

|-id=Selenium-76

| ⁷⁶Se

| style="text-align:right" | 34

| style="text-align:right" | 42

| 75.919213702(17)

| colspan=3 align=center|Stable

| 0+

| 0.0923(7)

|-id=Selenium-77

| ⁷⁷Se

| style="text-align:right" | 34

| style="text-align:right" | 43

| 76.919914150(67)

| colspan=3 align=center|Stable

| 1/2−

| 0.0760(7)

|-id=Selenium-77m

| style="text-indent:1em" | ^77mSe

| colspan="3" style="text-indent:2em" | 161.9223(10) keV

| 17.36(5) s

| IT

| ⁷⁷Se

| 7/2+

|-id=Selenium-78

| ⁷⁸Se

| style="text-align:right" | 34

| style="text-align:right" | 44

| 77.91730924(19)

| colspan=3 align=center|Stable

| 0+

| 0.2369 (22)

|-id=Selenium-79

| ⁷⁹SeLong-lived fission product

| style="text-align:right" | 34

| style="text-align:right" | 45

| 78.91849925(24)

| 3.27(28)×10⁵ y

| β⁻

| ⁷⁹Br

| 7/2+

|-id=Selenium-79m

| rowspan=2 style="text-indent:1em" | ^79mSe

| rowspan=2 colspan="3" style="text-indent:2em" | 95.77(3) keV

| rowspan=2|3.900(18) min

| IT (99.94%)

| ⁷⁹Se

| rowspan=2|1/2−

| rowspan=2|

| β⁻ (0.056%)

| ⁷⁹Br

|-id=Selenium-80

| ⁸⁰Se

| style="text-align:right" | 34

| style="text-align:right" | 46

| 79.9165218(10)

| colspan=3 align=center|Observationally StableBelieved to decay by β⁻β⁻ to ⁸⁰Kr

| 0+

| 0.4980(36)

|-id=Selenium-81

| ⁸¹Se

| style="text-align:right" | 34

| style="text-align:right" | 47

| 80.9179930(10)

| 18.45(12) min

| β⁻

| ⁸¹Br

| 1/2−

|-id=Selenium-81m

| rowspan=2 style="text-indent:1em" | ^81mSe

| rowspan=2 colspan="3" style="text-indent:2em" | 103.00(6) keV

| rowspan=2|57.28(2) min

| IT (99.95%)

| ⁸¹Se

| rowspan=2|7/2+

| rowspan=2|

| β⁻ (.051%)

| ⁸¹Br

|-id=Selenium-82

| ⁸²SePrimordial radionuclide

| style="text-align:right" | 34

| style="text-align:right" | 48

| 81.91669953(50)

| 8.76(15)×10¹⁹ y

| β⁻β⁻

| ⁸²Kr

| 0+

| 0.0882(15)

|-id=Selenium-83

| ⁸³Se

| style="text-align:right" | 34

| style="text-align:right" | 49

| 82.9191186(33)

| 22.25(4) min

| β⁻

| ⁸³Br

| 9/2+

|-id=Selenium-83m

| style="text-indent:1em" | ^83mSe

| colspan="3" style="text-indent:2em" | 228.92(7) keV

| 70.1(4) s

| β⁻

| ⁸³Br

| 1/2−

|-id=Selenium-84

| ⁸⁴Se

| style="text-align:right" | 34

| style="text-align:right" | 50

| 83.9184668(21)

| 3.26(10) min

| β⁻

| ⁸⁴Br

| 0+

|-id=Selenium-85

| ⁸⁵Se

| style="text-align:right" | 34

| style="text-align:right" | 51

| 84.9222608(28)

| 32.9(3) s

| β⁻

| ⁸⁵Br

| (5/2)+

|-id=Selenium-86

| rowspan=2|⁸⁶Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 52

| rowspan=2|85.9243117(27)

| rowspan=2|14.3(3) s

| β⁻

| ⁸⁶Br

| rowspan=2|0+

| rowspan=2|

| β⁻, n?

| ⁸⁵Br

|-id=Selenium-87

| rowspan=2|⁸⁷Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 53

| rowspan=2|86.9286886(24)

| rowspan=2|5.50(6) s

| β⁻ (99.50%)

| ⁸⁷Br

| rowspan=2|(3/2+)

| rowspan=2|

| β⁻, n (0.60%)

| ⁸⁶Br

|-id=Selenium-88

| rowspan=2|⁸⁸Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 54

| rowspan=2|87.9314175(36)

| rowspan=2|1.53(6) s

| β⁻ (99.01%)

| ⁸⁸Br

| rowspan=2|0+

| rowspan=2|

| β⁻, n (0.99%)

| ⁸⁷Br

|-id=Selenium-89

| rowspan=2|⁸⁹Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 55

| rowspan=2|88.9366691(40)

| rowspan=2|430(50) ms

| β⁻ (92.2%)

| ⁸⁹Br

| rowspan=2|5/2+#

| rowspan=2|

| β⁻, n (7.8%)

| ⁸⁸Br

|-id=Selenium-90

| rowspan=2|⁹⁰Se

| rowspan=2 style="text-align:right" | 34

| rowspan=2 style="text-align:right" | 56

| rowspan=2|89.94010(35)

| rowspan=2|210(80) ms

| β⁻

| ⁹⁰Br

| rowspan=2|0+

| rowspan=2|

| β⁻, n?

| ⁸⁹Br

|-id=Selenium-91

| rowspan=3|⁹¹Se

| rowspan=3 style="text-align:right" | 34

| rowspan=3 style="text-align:right" | 57

| rowspan=3|90.94570(47)

| rowspan=3|270(50) ms

| β⁻ (79%)

| ⁹¹Br

| rowspan=3|1/2+#

| rowspan=3|

| β⁻, n (21%)

| ⁹⁰Br

| β⁻, 2n?

| ⁸⁹Br

|-id=Selenium-92

| rowspan=3|⁹²Se

| rowspan=3 style="text-align:right" | 34

| rowspan=3 style="text-align:right" | 58

| rowspan=3|91.94984(43)#

| rowspan=3|90# ms [>300 ns]

| β⁻?

| ⁹²Br

| rowspan=3|0+

| rowspan=3|

| β⁻, n?

| ⁹¹Br

| β⁻, 2n?

| ⁹⁰Br

|-id=Selenium-92m

| style="text-indent:1em" | ^92mSe

| colspan="3" style="text-indent:2em" | 3072(2) keV

| 15.7(7) μs

| IT

| ⁹²Se

| (9−)

|-id=Selenium-93

| rowspan=3|⁹³Se

| rowspan=3 style="text-align:right" | 34

| rowspan=3 style="text-align:right" | 59

| rowspan=3|92.95614(43)#

| rowspan=3|130# ms [>300 ns]

| β⁻?

| ⁹³Br

| rowspan=3|1/2+#

| rowspan=3|

| β⁻, n?

| ⁹²Br

| β⁻, 2n?

| ⁹¹Br

|-id=Selenium-93m

| style="text-indent:1em" | ^93mSe

| colspan="3" style="text-indent:2em" | 678.2(7) keV

| 420(100) ns

| IT

| ⁹³Se

|-id=Selenium-94

| rowspan=3|⁹⁴Se

| rowspan=3 style="text-align:right" | 34

| rowspan=3 style="text-align:right" | 60

| rowspan=3|93.96049(54)#

| rowspan=3|50# ms [>300 ns]

| β⁻?

| ⁹⁴Br

| rowspan=3|0+

| rowspan=3|

| β⁻, n?

| ⁹³Br

| β⁻, 2n?

| ⁹²Br

|-id=Selenium-94m

| style="text-indent:1em" | ^94mSe

| colspan="3" style="text-indent:2em" | 2430.0(6) keV

| 680(50) ns

| IT

| ⁹⁴Se

| (7−)

|-id=Selenium-95

| rowspan=3|⁹⁵Se

| rowspan=3 style="text-align:right" | 34

| rowspan=3 style="text-align:right" | 61

| rowspan=3|94.96730(54)#

| rowspan=3|70# ms [>400 ns]

| β⁻?

| ⁹⁵Br

| rowspan=3|3/2+#

| rowspan=3|

| β⁻, n?

| ⁹⁴Br

| β⁻, 2n?

| ⁹³Br

|-id=Selenium-96

| ⁹⁶Se{{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 |doi=10.1103/PhysRevC.109.044313}}

| style="text-align:right" | 34

| style="text-align:right" | 62

|-id=Selenium-97

| ⁹⁷Se

| style="text-align:right" | 34

| style="text-align:right" | 63

Use of radioisotopes

The isotope selenium-75 has radiopharmaceutical uses. For example, it is used in high-dose-rate endorectal brachytherapy, as an alternative to iridium-192.{{cite journal | title = Dosimetric Considerations for Ytterbium-169, Selenium-75, and Iridium-192 Radioisotopes in High-Dose-Rate Endorectal Brachytherapy | author1 = Shoemaker T | author2 = Vuong T | author3 = Glickman H | author4 = Kaifi S | author5 = Famulari G | author6 =Enger SA | journal = Int J Radiat Oncol Biol Phys | year = 2019 | volume = 105 | issue = 4 | pages = 875–883 | doi = 10.1016/j.ijrobp.2019.07.003 | pmid = 31330175 | s2cid = 198170324 }}

In paleobiogeochemistry, the ratio in amount of selenium-82 to selenium-76 (i.e, the value of δ^82/76Se) can be used to track down the redox conditions on Earth during the Neoproterozoic era in order to gain a deeper understanding of the rapid oxygenation that trigger the emergence of complex organisms.{{Cite journal |last1=Pogge von Strandmann |first1=Philip A. E. |last2=Stüeken |first2=Eva E. |last3=Elliott |first3=Tim |last4=Poulton |first4=Simon W. |last5=Dehler |first5=Carol M. |last6=Canfield |first6=Don E. |last7=Catling |first7=David C. |date=2015-12-18 |title=Selenium isotope evidence for progressive oxidation of the Neoproterozoic biosphere |url=https://www.nature.com/articles/ncomms10157 |journal=Nature Communications |language=en |volume=6 |issue=1 |pages=10157 |doi=10.1038/ncomms10157 |pmid=26679529 |pmc=4703861 |issn=2041-1723|doi-access=free }}{{Cite web |last=Stüeken |first=Eva E. |title=Selenium isotopes as a biogeochemical proxy in deep time |url=https://core.ac.uk/download/pdf/161931618.pdf |website=core.ac.uk}}

References

Isotope masses from:
{{NUBASE 2003}}
Isotopic compositions and standard atomic masses from:
{{CIAAW2003}}
{{CIAAW 2005}}
Half-life, spin, and isomer data selected from the following sources.
{{NUBASE 2003}}
{{NNDC}}
{{CRC85|chapter=11}}

Category:Selenium

Selenium