硒的同位素
圖表

| 符號 | Z> 激發能量 | N> 激發能量 | 同位素質量（u） > 激發能量 | 半衰期 | 衰變方式 | 衰變產物 | 原子核 自旋 | 相對豐度 （莫耳分率） | 相對豐度 的變化量 （莫耳分率） |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 65Se | 34 | 31 | 64.96466(64)# | <50 ms | β+ (>99.9%) | 65As | 3/2-# |  |  |
| 65Se | 34 | 31 | 64.96466(64)# | <50 ms | β+, p (<.1%) | 64Ge | 3/2-# |  |  |
| 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-# |  |  |
| 67Se | 34 | 33 | 66.95009(21)# | 133(11) ms | β+, p (.5%) | 66Ge | 5/2-# |  |  |
| 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-) |  |  |
| 69Se | 34 | 35 | 68.93956(4) | 27.4(2) s | β+, p (.045%) | 68Ge | (1/2-) |  |  |
| 69m1Se | 39.4(1) keV | 39.4(1) keV | 39.4(1) keV | 2.0(2) µs |  |  | 5/2- |  |  |
| 69m2Se | 573.9(10) keV | 573.9(10) keV | 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 | 48.79(5) keV | 48.79(5) keV | 5.6(7) µs |  |  | 1/2- to 9/2- |  |  |
| 71m2Se | 260.48(10) keV | 260.48(10) keV | 260.48(10) keV | 19.0(5) µs |  |  | (9/2)+ |  |  |
| 72Se | 34 | 38 | 71.927112(13) | 8.40(8) d | ε | 72As | 0+ |  |  |
| 73Se | 34 | 39 | 72.926765(11) | 7.15(8) h | β+ | 73As | 9/2+ |  |  |
| 73mSe | 25.71(4) keV | 25.71(4) keV | 25.71(4) keV | 39.8(13) min | IT | 73Se | 3/2- |  |  |
| 73mSe | 25.71(4) keV | 25.71(4) keV | 25.71(4) keV | 39.8(13) min | β+ | 73As | 3/2- |  |  |
| 74Se | 34 | 40 | 73.9224764(18) | 觀測上穩定  | 觀測上穩定  | 觀測上穩定  | 0+ | 0.0089(4) |  |
| 75Se | 34 | 41 | 74.9225234(18) | 119.779(4) d | ε | 75As | 5/2+ |  |  |
| 76Se | 34 | 42 | 75.9192136(18) | 稳定 | 稳定 | 稳定 | 0+ | 0.0937(29) |  |
| 77Se | 34 | 43 | 76.9199140(18) | 稳定 | 稳定 | 稳定 | 1/2- | 0.0763(16) |  |
| 77mSe | 161.9223(7) keV | 161.9223(7) keV | 161.9223(7) keV | 17.36(5) s | IT | 77Se | 7/2+ |  |  |
| 78Se | 34 | 44 | 77.9173091(18) | 稳定 | 稳定 | 稳定 | 0+ | 0.2377(28) |  |
| 79Se（英语：） | 34 | 45 | 78.9184991(18) | 3.27(8)×105 y | β− | 79Br | 7/2+ |  |  |
| 79mSe | 95.77(3) keV | 95.77(3) keV | 95.77(3) keV | 3.92(1) min | IT (99.944%) | 79Se | 1/2- |  |  |
| 79mSe | 95.77(3) keV | 95.77(3) keV | 95.77(3) keV | 3.92(1) min | β− (.056%) | 79Br | 1/2- |  |  |
| 80Se | 34 | 46 | 79.9165213(21) | 觀測上穩定 | 觀測上穩定 | 觀測上穩定 | 0+ | 0.4961(41) |  |
| 81Se | 34 | 47 | 80.9179925(22) | 18.45(12) min | β− | 81Br | 1/2- |  |  |
| 81mSe | 102.99(6) keV | 102.99(6) keV | 102.99(6) keV | 57.28(2) min | IT (99.948%) | 81Se | 7/2+ |  |  |
| 81mSe | 102.99(6) keV | 102.99(6) keV | 102.99(6) keV | 57.28(2) min | β− (.052%) | 81Br | 7/2+ |  |  |
| 82Se | 34 | 48 | 81.9166994(22) | 0.97(5)×1020 y | β−β− | 82Kr | 0+ | 0.0873(22) |  |
| 83Se | 34 | 49 | 82.919118(4) | 22.3(3) min | β− | 83Br | 9/2+ |  |  |
| 83mSe | 228.50(20) keV | 228.50(20) keV | 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+)# |  |  |
| 87Se | 34 | 53 | 86.92852(4) | 5.50(12) s | β−, n (.36%) | 86Br | (5/2+)# |  |  |
| 88Se | 34 | 54 | 87.93142(5) | 1.53(6) s | β− (99.01%) | 88Br | 0+ |  |  |
| 88Se | 34 | 54 | 87.93142(5) | 1.53(6) s | β−, n (.99%) | 88Br | 0+ |  |  |
| 89Se | 34 | 55 | 88.93645(32)# | 0.41(4) s | β− (92.2%) | 89Br | (5/2+)# |  |  |
| 89Se | 34 | 55 | 88.93645(32)# | 0.41(4) s | β−, n (7.8%) | 88Br | (5/2+)# |  |  |
| 90Se | 34 | 56 | 89.93996(43)# | 300# ms [>300 ns] | β−, n | 89Br | 0+ |  |  |
| 90Se | 34 | 56 | 89.93996(43)# | 300# ms [>300 ns] | β− | 90Br | 0+ |  |  |
| 91Se | 34 | 57 | 90.94596(54)# | 270(50) ms | β− (79%) | 91Br | 1/2+# |  |  |
| 91Se | 34 | 57 | 90.94596(54)# | 270(50) ms | β−, n | 90Br | 1/2+# |  |  |
| 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 2 3  畫上#號的數據代表沒有經過實驗的証明，僅為理論推測。
1 2 3 4  用括號括起來的數據代表不確定性。
↑  半衰期超过5亿年的同位素以粗體表示。
↑  穩定的衰變產物以粗體表示。
↑  Believed to decay by β+β+ to 74Ge
↑  Long-lived fission product
↑  Believed to decay by β−β− to 80Kr
↑  Primordial radionuclide
| 0 | 1 | 2 |
| --- | --- | --- |

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