Se
Selenium
Z 34 78.971 g/molOther Nonmetal
| 80Se | 46 | 79.9165 | -77,759.5 | 49.8% | Stable | 0+ | β⁻ | 1922 |
| 78Se | 44 | 77.9173 | -77,025.95 | 23.69% | Stable | 0+ | --- | 1922 |
| 76Se | 42 | 75.9192 | -75,251.959 | 9.23% | Stable | 0+ | --- | 1922 |
| 82Se | 48 | 81.9167 | -77,593.9 | 8.82% | 87.6 Ey | 0+ | β⁻(100%) | 1922 |
| 77Se | 43 | 76.9199 | -74,599.5 | 7.6% | Stable | 1/2- | --- | 1922 |
| 74Se | 40 | 73.9225 | -72,213.21 | 0.86% | Stable | 0+ | β⁺ | 1922 |
| 63Se | 29 | 62.9819 | -16,850.0 | --- | 13.2 ms | (3/2-) | β⁺p→62Ge(89%) β⁺→63As(11%) p→61Ge(<0.5%) | 2016 |
| 64Se | 30 | 63.9712 | -26,860.0 | --- | 22.6 ms | 0+ | β⁺→64As β⁺p→63Ge | 2005 |
| 65Se | 31 | 64.9646 | -33,020.0 | --- | 34.2 ms | (3/2-) | β⁺p→64Ge(87%) β⁺→65As(13%) | 1993 |
| 66Se | 32 | 65.9553 | -41,660.0 | --- | 54.0 ms | 0+ | β⁺→66As(100%) β⁺p→65Ge | 1993 |
| 67Se | 33 | 66.95 | -46,580.0 | --- | 133.0 ms | (5/2-) | β⁺→67As(99.5%) β⁺p→66Ge(0.5%) | 1991 |
| 68Se | 34 | 67.9418 | -54,189.4 | --- | 35.5 s | 0+ | β⁺→68As(100%) | 1990 |
| 69Se | 35 | 68.9394 | -56,434.7 | --- | 27.4 s | 1/2- | β⁺→69As(99.948%) β⁺p→68Ge(0.052%) | 1974 |
| 69mSe | 35 | 68.9395 | -56,395.9 | --- | 2.0 µs | 5/2- | γ→69Se(100%) | 1988 |
| 69nSe | 35 | 68.94 | -55,860.7 | --- | 955.0 ns | 9/2+ | γ→69Se(100%) | 1988 |
| 70Se | 36 | 69.9335 | -61,929.9 | --- | 41.1 m | 0+ | β⁺→70As(100%) | 1950 |
| 71Se | 37 | 70.9322 | -63,146.5 | --- | 4.74 m | (5/2-) | β⁺→71As(100%) | 1957 |
| 71mSe | 37 | 70.9323 | -63,097.7 | --- | 5.6 µs | (1/2-) | γ→71Se(100%) | 1982 |
| 71nSe | 37 | 70.9325 | -62,886.0 | --- | 19.0 µs | (9/2+) | γ→71Se(100%) | 1982 |
| 72Se | 38 | 71.9271 | -67,868.2 | --- | 8.4 d | 0+ | EC→72As(100%) | 1948 |
| 73Se | 39 | 72.9268 | -68,227.0 | --- | 7.15 h | 9/2+ | β⁺→73As(100%) | 1948 |
| 73mSe | 39 | 72.9268 | -68,201.0 | --- | 39.8 m | 3/2- | γ→73Se(72.6%) β⁺→73As(27.4%) | 1960 |
| 75Se | 41 | 74.9225 | -72,169.49 | --- | 119.78 d | 5/2+ | EC→75As(100%) | 1947 |
| 77mSe | 43 | 76.9201 | -74,437.58 | --- | 17.36 s | 7/2+ | γ→77Se(100%) | 1947 |
| 79Se | 45 | 78.9185 | -75,917.47 | --- | 327.0 ky | 7/2+ | β⁻→79Br(100%) | 1950 |
| 79mSe | 45 | 78.9186 | -75,821.7 | --- | 3.9 m | 1/2- | γ→79Se(~100%) β⁻→79Br(0.056%) | 1950 |
| 81Se | 47 | 80.918 | -76,389.0 | --- | 18.45 m | 1/2- | β⁻→81Br(100%) | 1948 |
| 81mSe | 47 | 80.9181 | -76,286.0 | --- | 57.28 m | 7/2+ | γ→81Se(~100%) β⁻→81Br(0.051%) | 1971 |
| 83Se | 49 | 82.9191 | -75,341.0 | --- | 22.25 m | 9/2+ | β⁻→83Br(100%) | 1937 |
| 83mSe | 49 | 82.9194 | -75,112.0 | --- | 1.17 m | 1/2- | β⁻→83Br(100%) | 1969 |
| 84Se | 50 | 83.9185 | -75,947.7 | --- | 3.26 m | 0+ | β⁻→84Br(100%) | 1960 |
| 85Se | 51 | 84.9223 | -72,413.6 | --- | 32.9 s | (5/2+) | β⁻→85Br(100%) | 1960 |
| 86Se | 52 | 85.9243 | -70,503.2 | --- | 14.3 s | 0+ | β⁻→86Br(100%) β⁻n→85Br | 1973 |
| 87Se | 53 | 86.9287 | -66,426.1 | --- | 5.5 s | (3/2+) | β⁻→87Br(99.4%) β⁻n→86Br(0.6%) | 1968 |
| 88Se | 54 | 87.9314 | -63,884.0 | --- | 1.53 s | 0+ | β⁻→88Br(99.01%) β⁻n→87Br(0.99%) | 1970 |
| 89Se | 55 | 88.9367 | -58,992.0 | --- | 430.0 ms | (5/2+) | β⁻→89Br(92.2%) β⁻n→88Br(7.8%) | 1971 |
| 90Se | 56 | 89.9401 | -55,800.0 | --- | 210.0 ms | 0+ | β⁻→90Br(100%) β⁻n→89Br | 1994 |
| 91Se | 57 | 90.9457 | -50,580.0 | --- | 270.0 ms | (1/2+) | β⁻→91Br(79%) β⁻n→90Br(21%) β⁻n→89Br | 1975 |
| 92Se | 58 | 91.9498 | -46,720.0 | --- | 90.0 ms | 0+ | β⁻→92Br β⁻n→91Br β⁻n→90Br | 1997 |
| 92mSe | 58 | 91.9519 | -44,780.0 | --- | 15.7 µs | (9-) | γ→92Se(100%) | 2012 |
| 93Se | 59 | 92.9561 | -40,860.0 | --- | 130.0 ms | (1/2+) | β⁻→93Br β⁻n→92Br β⁻n→91Br | 1997 |
| 93mSe | 59 | 92.9569 | -40,180.0 | --- | 420.0 ns | --- | γ→93Se(100%) | 2012 |
| 94Se | 60 | 93.9605 | -36,800.0 | --- | 50.0 ms | 0+ | β⁻→94Br β⁻n→93Br β⁻n→92Br | 1997 |
| 94mSe | 60 | 93.9631 | -34,370.0 | --- | 680.0 ns | (7-) | γ→94Se(100%) | 2020 |
| 95Se | 61 | 94.9673 | -30,460.0 | --- | 70.0 ms | (3/2+) | β⁻→95Br β⁻n→94Br β⁻n→93Br | 2010 |