It's Elemental
Isotopes of the Element Selenium
Selenium
Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information.
Isotopes With A Known Natural Abundance
| Mass Number | Natural Abundance | Half-life |
| 74 | 0.89% | STABLE |
| 76 | 9.37% | STABLE |
| 77 | 7.63% | STABLE |
| 78 | 23.77% | STABLE |
| 80 | 49.61% | STABLE |
| 82 | 8.73% | STABLE |
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 64 | > 180 nanoseconds | Electron Capture | 100.00% |
| 65 | 33 milliseconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | 100.00% | ||
| 66 | No Data Available | No Data Available | No Data Available |
| 67 | 136 milliseconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | 0.50% | ||
| 68 | 35.5 seconds | Electron Capture | 100.00% |
| 69 | 27.4 seconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | 0.05% | ||
| 70 | 41.1 minutes | Electron Capture | 100.00% |
| 71 | 4.74 minutes | Electron Capture | 100.00% |
| 72 | 8.40 days | Electron Capture | 100.00% |
| 73 | 7.15 hours | Electron Capture | 100.00% |
| 73m | 39.8 minutes | Isomeric Transition | 72.60% |
| Electron Capture | 27.40% | ||
| 74 | STABLE | - | - |
| 75 | 119.79 days | Electron Capture | 100.00% |
| 76 | STABLE | - | - |
| 77 | STABLE | - | - |
| 77m | 17.4 seconds | Isomeric Transition | 100.00% |
| 78 | STABLE | - | - |
| 79 | 2.95×10+5 years | Beta-minus Decay | 100.00% |
| 79m | 3.92 minutes | Isomeric Transition | 99.94% |
| Beta-minus Decay | 0.06% | ||
| 80 | STABLE | - | - |
| 81 | 18.45 minutes | Beta-minus Decay | 100.00% |
| 81m | 57.28 minutes | Isomeric Transition | 99.95% |
| Beta-minus Decay | 0.05% | ||
| 82 | STABLE | - | - |
| 83 | 22.3 minutes | Beta-minus Decay | 100.00% |
| 83m | 70.1 seconds | Beta-minus Decay | 100.00% |
| 84 | 3.26 minutes | Beta-minus Decay | 100.00% |
| 85 | 32.9 seconds | Beta-minus Decay | 100.00% |
| 86 | 14.3 seconds | Beta-minus Decay | 100.00% |
| 87 | 5.50 seconds | Beta-minus Decay | 100.00% |
| Beta-minus Decay with delayed Neutron Emission | 0.20% | ||
| 88 | 1.53 seconds | Beta-minus Decay | 100.00% |
| Beta-minus Decay with delayed Neutron Emission | 0.67% | ||
| 89 | 0.41 seconds | Beta-minus Decay with delayed Neutron Emission | 7.80% |
| Beta-minus Decay | 100.00% | ||
| 90 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available | ||
| 91 | 0.27 seconds | Beta-minus Decay | 100.00% |
| Beta-minus Decay with delayed Neutron Emission | 21.00% | ||
| 92 | No Data Available | Beta-minus Decay | 100.00% |
| 93 | No Data Available | Beta-minus Decay | 100.00% |
| 94 | > 150 nanoseconds | Beta-minus Decay | 100.00% |
| 95 | > 300 nanoseconds | Beta-minus Decay (suspected) | No Data Available |
| 95m | 300 nanoseconds | Beta-minus Decay with delayed Neutron Emission (suspected) | No Data Available |
| 95m1 | > 300 nanoseconds | Beta-minus Decay with delayed Double Neutron Emission (suspected) | No Data Available |
Citation and linking information
For questions about this page, please contact Carol McKisson.