セレン（Se）の同位体のうち天然に生成するものは6種類あり、そのうち74Se、76Se、77Se、78Se、80Seの5種類が安定同位体である。最後の3つと、半減期が29万5000年の79Se、1020年以上の82Seは核分裂生成物である。その他23種類の不安定同位体が見つかっている。
標準原子量は78.96(3) uである。
一覧
| 同位体核種
|
Z(p)
|
N(n)
|
同位体質量 (u)
|
半減期
|
核スピン数
|
天然存在比
|
天然存在比
(範囲)
|
| 励起エネルギー
|
|---|
|
65Se
|
34
|
31
|
64.96466(64)#
|
<50 ms
|
3/2-#
|
|
|
|
66Se
|
34
|
32
|
65.95521(32)#
|
33(12) ms
|
0+
|
|
|
|
67Se
|
34
|
33
|
66.95009(21)#
|
133(11) ms
|
5/2-#
|
|
|
|
68Se
|
34
|
34
|
67.94180(4)
|
35.5(7) s
|
0+
|
|
|
|
69Se
|
34
|
35
|
68.93956(4)
|
27.4(2) s
|
(1/2-)
|
|
|
|
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
|
0+
|
|
|
|
71Se
|
34
|
37
|
70.93224(3)
|
4.74(5) min
|
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
|
0+
|
|
|
|
73Se
|
34
|
39
|
72.926765(11)
|
7.15(8) h
|
9/2+
|
|
|
|
73mSe
|
25.71(4) keV
|
39.8(13) min
|
3/2-
|
|
|
|
74Se
|
34
|
40
|
73.9224764(18)
|
STABLE
|
0+
|
0.0089(4)
|
|
|
75Se
|
34
|
41
|
74.9225234(18)
|
119.779(4) d
|
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
|
7/2+
|
|
|
|
78Se
|
34
|
44
|
77.9173091(18)
|
STABLE
|
0+
|
0.2377(28)
|
|
|
79Se
|
34
|
45
|
78.9184991(18)
|
2.95(38)E+5 a
|
7/2+
|
|
|
|
79mSe
|
95.77(3) keV
|
3.92(1) min
|
1/2-
|
|
|
|
80Se
|
34
|
46
|
79.9165213(21)
|
STABLE
|
0+
|
0.4961(41)
|
|
|
81Se
|
34
|
47
|
80.9179925(22)
|
18.45(12) min
|
1/2-
|
|
|
|
81mSe
|
102.99(6) keV
|
57.28(2) min
|
7/2+
|
|
|
|
82Se
|
34
|
48
|
81.9166994(22)
|
97(5)E+18 a
|
0+
|
0.0873(22)
|
|
|
83Se
|
34
|
49
|
82.919118(4)
|
22.3(3) min
|
9/2+
|
|
|
|
83mSe
|
228.50(20) keV
|
70.1(4) s
|
1/2-
|
|
|
|
84Se
|
34
|
50
|
83.918462(16)
|
3.1(1) min
|
0+
|
|
|
|
85Se
|
34
|
51
|
84.92225(3)
|
31.7(9) s
|
(5/2+)#
|
|
|
|
86Se
|
34
|
52
|
85.924272(17)
|
15.3(9) s
|
0+
|
|
|
|
87Se
|
34
|
53
|
86.92852(4)
|
5.50(12) s
|
(5/2+)#
|
|
|
|
88Se
|
34
|
54
|
87.93142(5)
|
1.53(6) s
|
0+
|
|
|
|
89Se
|
34
|
55
|
88.93645(32)#
|
0.41(4) s
|
(5/2+)#
|
|
|
|
90Se
|
34
|
56
|
89.93996(43)#
|
300# ms [>300 ns]
|
0+
|
|
|
|
91Se
|
34
|
57
|
90.94596(54)#
|
270(50) ms
|
1/2+#
|
|
|
|
92Se
|
34
|
58
|
91.94992(64)#
|
100# ms [>300 ns]
|
0+
|
|
|
|
93Se
|
34
|
59
|
92.95629(86)#
|
50# ms [>300 ns]
|
1/2+#
|
|
|
|
94Se
|
34
|
60
|
93.96049(86)#
|
20# ms [>300 ns]
|
0+
|
|
|
参考文献
- Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
- Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
- Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.
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