Most of the isotope data on this site has been obtained from the National Nuclear Data Center.
Naturally Occurring Isotopes
| Mass Number | Natural Abundance | Half-life |
| 141 | 100% | STABLE |
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 121 | 10 milliseconds | Proton Emission | 100.00% |
| 122 | 0.5 seconds | Electron Capture (suspected) | No Data Available |
| 123 | 0.8 seconds | Electron Capture (suspected) | No Data Available |
| 124 | 1.2 seconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | > 0.00% | ||
| 125 | 3.3 seconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | No Data Available | ||
| 126 | 3.14 seconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | No Data Available | ||
| 127 | 4.2 seconds | Electron Capture | 100.00% |
| 128 | 2.84 seconds | Electron Capture | 100.00% |
| 129 | 30 seconds | Electron Capture | > 0.00% |
| 130 | 40 seconds | Electron Capture | 100.00% |
| Electron Capture | 100.00% | ||
| Electron Capture | 100.00% | ||
| 131 | 1.51 minutes | Electron Capture | 100.00% |
| 131m | 5.73 seconds | Isomeric Transition | 96.40% |
| Electron Capture | 3.60% | ||
| 132 | 1.6 minutes | Electron Capture | 100.00% |
| 133 | 6.5 minutes | Electron Capture | 100.00% |
| 133m | 1.1 seconds | Isomeric Transition | 100.00% |
| 134 | ≈ 11 minutes | Electron Capture | 100.00% |
| 134m | 17 minutes | Electron Capture | 100.00% |
| 135 | 24 minutes | Electron Capture | 100.00% |
| 136 | 13.1 minutes | Electron Capture | 100.00% |
| 137 | 1.28 hours | Electron Capture | 100.00% |
| 138 | 1.45 minutes | Electron Capture | 100.00% |
| 138m | 2.12 hours | Electron Capture | 100.00% |
| 139 | 4.41 hours | Electron Capture | 100.00% |
| 140 | 3.39 minutes | Electron Capture | 100.00% |
| 141 | STABLE | - | - |
| 142 | 19.12 hours | Beta-minus Decay | 99.98% |
| Electron Capture | 0.02% | ||
| 142m | 14.6 minutes | Isomeric Transition | 100.00% |
| 143 | 13.57 days | Beta-minus Decay | 100.00% |
| 144 | 17.28 minutes | Beta-minus Decay | 100.00% |
| 144m | 7.2 minutes | Isomeric Transition | 99.93% |
| Beta-minus Decay | 0.07% | ||
| 145 | 5.984 hours | Beta-minus Decay | 100.00% |
| 146 | 24.15 minutes | Beta-minus Decay | 100.00% |
| 147 | 13.4 minutes | Beta-minus Decay | 100.00% |
| 148 | 2.29 minutes | Beta-minus Decay | 100.00% |
| 148m | 2.01 minutes | Beta-minus Decay | 100.00% |
| 149 | 2.26 minutes | Beta-minus Decay | 100.00% |
| 150 | 6.19 seconds | Beta-minus Decay | 100.00% |
| 151 | 18.90 seconds | Beta-minus Decay | 100.00% |
| 152 | 3.57 seconds | Beta-minus Decay | 100.00% |
| 153 | 4.28 seconds | Beta-minus Decay | 100.00% |
| 154 | 2.3 seconds | Beta-minus Decay | 100.00% |
| 155 | > 300 nanoseconds | Beta-minus Decay (suspected) | No Data Available |
| 156 | > 300 nanoseconds | Beta-minus Decay (suspected) | No Data Available |
| 157 | No Data Available | Beta-minus Decay (suspected) | No Data Available |
| 158 | No Data Available | Beta-minus Decay (suspected) | No Data Available |
| 159 | No Data Available | Beta-minus Decay (suspected) | No Data Available |
This page is maintained by Steve Gagnon.