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 [編集]
| 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 [編集]
- 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.
