Isotopes of selenium














Main isotopes of selenium .mw-parser-output .nobold{font-weight:normal}
(34Se)











































































Iso­tope

Decay


abun­dance

half-life
(t1/2)

mode

pro­duct

72Se

syn
8.4 d

ε

72As

γ



74Se
0.86%

stable

75Se
syn
119.8 d
ε

75As
γ



76Se
9.23%
stable

77Se
7.60%
stable

78Se
23.69%
stable

79Se

trace
3.27×105 y

β

79Br

80Se
49.80%
stable

82Se
8.82%
1.08×1020 y

ββ

82Kr


Standard atomic weight
(Ar, standard)
  • 78.971(8)[1]

The chemical element selenium (34Se) 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,[2][3] 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.




Contents






  • 1 List of isotopes


    • 1.1 Notes




  • 2 See also


  • 3 References





List of isotopes




















































































































































































































































































































































































































































































































nuclide
symbol
Z(p)
N(n)
 
isotopic mass (u)
 
half-life[n 1]
decay
mode(s)[4][n 2]
daughter
isotope(s)[n 3]
nuclear
spin and
parity
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy

65Se
34
31
64.96466(64)#
<50 ms

β+ (>99.9%)

65As
3/2−#


β+, p (<.1%)

64Ge

66Se
34
32
65.95521(32)#
33(12) ms
β+

66As
0+



67Se
34
33
66.95009(21)#
133(11) ms
β+ (99.5%)

67As
5/2−#


β+, p (.5%)

66Ge

68Se
34
34
67.94180(4)
35.5(7) s
β+

68As
0+



69Se
34
35
68.93956(4)
27.4(2) s
β+ (99.955%)

69As
(1/2−)


β+, p (.045%)

68Ge

69m1Se
39.4(1) keV
2.0(2) µs


5/2−



69m2Se
573.9(10) keV
955(16) ns


9/2+



70Se
34
36
69.93339(7)
41.1(3) min
β+

70As
0+



71Se
34
37
70.93224(3)
4.74(5) min
β+

71As
5/2−



71m1Se
48.79(5) keV
5.6(7) µs


1/2− to 9/2−



71m2Se
260.48(10) keV
19.0(5) µs


(9/2)+



72Se
34
38
71.927112(13)
8.40(8) d

EC

72As
0+



73Se
34
39
72.926765(11)
7.15(8) h
β+

73As
9/2+



73mSe
25.71(4) keV
39.8(13) min

IT

73Se
3/2−


β+

73As

74Se
34
40
73.9224764(18)

Observationally Stable [n 4]
0+
0.0089(4)


75Se
34
41
74.9225234(18)
119.779(4) d
EC

75As
5/2+



76Se
34
42
75.9192136(18)

Stable
0+
0.0937(29)


77Se
34
43
76.9199140(18)

Stable
1/2−
0.0763(16)


77mSe
161.9223(7) keV
17.36(5) s
IT

77Se
7/2+



78Se
34
44
77.9173091(18)

Stable
0+
0.2377(28)


79Se[n 5]
34
45
78.9184991(18)
3.27(8)×105 y
β

79Br
7/2+



79mSe
95.77(3) keV
3.92(1) min
IT (99.944%)

79Se
1/2−


β (.056%)

79Br

80Se
34
46
79.9165213(21)

Observationally Stable[n 6]
0+
0.4961(41)


81Se
34
47
80.9179925(22)
18.45(12) min
β

81Br
1/2−



81mSe
102.99(6) keV
57.28(2) min
IT (99.948%)

81Se
7/2+


β (.052%)

81Br

82Se[n 7]
34
48
81.9166994(22)

0.97(5)×1020 y
ββ

82Kr
0+
0.0873(22)


83Se
34
49
82.919118(4)
22.3(3) min
β

83Br
9/2+



83mSe
228.50(20) keV
70.1(4) s
β

83Br
1/2−



84Se
34
50
83.918462(16)
3.1(1) min
β

84Br
0+



85Se
34
51
84.92225(3)
31.7(9) s
β

85Br
(5/2+)#



86Se
34
52
85.924272(17)
15.3(9) s
β

86Br
0+



87Se
34
53
86.92852(4)
5.50(12) s
β (99.64%)

87Br
(5/2+)#


β, n (.36%)

86Br

88Se
34
54
87.93142(5)
1.53(6) s
β (99.01%)

88Br
0+


β, n (.99%)

88Br

89Se
34
55
88.93645(32)#
0.41(4) s
β (92.2%)

89Br
(5/2+)#


β, n (7.8%)

88Br

90Se
34
56
89.93996(43)#
300# ms [>300 ns]
β, n

89Br
0+


β

90Br

91Se
34
57
90.94596(54)#
270(50) ms
β (79%)

91Br
1/2+#


β, n

90Br

92Se
34
58
91.94992(64)#
100# ms [>300 ns]
β

92Br
0+



93Se
34
59
92.95629(86)#
50# ms [>300 ns]


1/2+#



94Se
34
60
93.96049(86)#
20# ms [>300 ns]


0+





  1. ^ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)


  2. ^ Abbreviations:
    EC: Electron capture
    IT: Isomeric transition



  3. ^ Bold for stable isotopes


  4. ^ Believed to decay by β+β+ to 74Ge


  5. ^ Long-lived fission product


  6. ^ Believed to decay by ββ to 80Kr


  7. ^ Primordial radionuclide



Notes



  • The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.

  • Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.

  • Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.



See also



  • Selenium

  • Selenium-79



References





  1. ^ Meija, J.; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}


  2. ^ The half-life of 79Se Archived September 27, 2011, at the Wayback Machine.


  3. ^ Jorg, Gerhard; Buhnemann, Rolf; Hollas, Simon; Kivel, Niko; Kossert, Karsten; Van Winckel, Stefaan; Gostomski, Christoph Lierse v. (2010). "Preparation of radiochemically pure 79Se and highly precise determination of its half-life". Applied Radiation and Isotopes. 68 (12): 2339–51. doi:10.1016/j.apradiso.2010.05.006. PMID 20627600.


  4. ^ "Universal Nuclide Chart". nucleonica. (Registration required (help)).




  • Isotope masses from:

    • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. Archived from the original (PDF) on 2008-09-23.


  • Isotopic compositions and standard atomic masses from:


    • J. R. de Laeter; J. K. Böhlke; P. De Bièvre; H. Hidaka; H. S. Peiser; K. J. R. Rosman; P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.


    • M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.



  • Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.


    • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. Archived from the original (PDF) on 2008-09-23.


    • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005. Check date values in: |accessdate= (help)


    • N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.











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