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 |
| 152 | 0.20% | 1.08×1014 years |
| 154 | 2.18% | STABLE |
| 155 | 14.80% | STABLE |
| 156 | 20.47% | STABLE |
| 157 | 15.65% | STABLE |
| 158 | 24.84% | STABLE |
| 160 | 21.86% | > 3.1×10+19 years |
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 133 | No Data Available | No Data Available | No Data Available |
| 134 | No Data Available | Electron Capture (suspected) | No Data Available |
| 135 | 1.1 seconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | 18.00% | ||
| 136 | >= 200 nanoseconds | No Data Available | No Data Available |
| 137 | 2.2 seconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | No Data Available | ||
| 138 | 4.7 seconds | Electron Capture | 100.00% |
| 139 | 5.8 seconds | Electron Capture with delayed Proton Emission | > 0.00% |
| Electron Capture | > 0.00% | ||
| 139m | 4.8 seconds | Electron Capture | > 0.00% |
| Electron Capture with delayed Proton Emission | > 0.00% | ||
| 140 | 15.8 seconds | Electron Capture | 100.00% |
| 141 | 14 seconds | Electron Capture | 100.00% |
| Electron Capture with delayed Proton Emission | 0.03% | ||
| 141m | 24.5 seconds | Electron Capture | 89.00% |
| Isomeric Transition | 11.00% | ||
| 142 | 70.2 seconds | Electron Capture | 100.00% |
| 143 | 39 seconds | Electron Capture | 100.00% |
| 143m | 110.0 seconds | Electron Capture | 100.00% |
| 144 | 4.47 minutes | Electron Capture | 100.00% |
| 145 | 23.0 minutes | Electron Capture | 100.00% |
| 145m | 85 seconds | Isomeric Transition | 94.30% |
| Electron Capture | 5.70% | ||
| 146 | 48.27 days | Electron Capture | 100.00% |
| 147 | 38.06 hours | Electron Capture | 100.00% |
| 148 | 70.9 years | Alpha Decay | 100.00% |
| 149 | 9.28 days | Electron Capture | 100.00% |
| Alpha Decay | 4.3×10-4 % | ||
| 150 | 1.79×10+6 years | Alpha Decay | 100.00% |
| 151 | 123.9 days | Electron Capture | 100.00% |
| Alpha Decay | ~ 8.0×10-7 % | ||
| 152 | 1.08×1014 years | Alpha Decay | 100.00% |
| 153 | 240.4 days | Electron Capture | 100.00% |
| 154 | STABLE | - | - |
| 155 | STABLE | - | - |
| 155m | 31.97 milliseconds | Isomeric Transition | 100.00% |
| 156 | STABLE | - | - |
| 157 | STABLE | - | - |
| 158 | STABLE | - | - |
| 159 | 18.479 hours | Beta-minus Decay | 100.00% |
| 160 | > 3.1×10+19 years | Double Beta-minus Decay | No Data Available |
| 161 | 3.66 minutes | Beta-minus Decay | 100.00% |
| 162 | 8.4 minutes | Beta-minus Decay | 100.00% |
| 163 | 68 seconds | Beta-minus Decay | 100.00% |
| 164 | 45 seconds | Beta-minus Decay | 100.00% |
| 165 | 10.3 seconds | Beta-minus Decay | 100.00% |
| 166 | 4.8 seconds | Beta-minus Decay | 100.00% |
| 167 | No Data Available | Beta-minus Decay (suspected) | No Data Available |
| 168 | No Data Available | Beta-minus Decay (suspected) | No Data Available |
| 169 | No Data Available | Beta-minus Decay (suspected) | No Data Available |
This page is maintained by Steve Gagnon.