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 |
| 232 | 100% | 1.40×1010 years |
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 208 | 1.7 milliseconds | Alpha Decay | 100.00% |
| 209 | 2.5 milliseconds | Alpha Decay | No Data Available |
| 210 | 16 milliseconds | Electron Capture | ~ 1.00% |
| Alpha Decay | 99.00% | ||
| 211 | 0.04 seconds | Alpha Decay | No Data Available |
| 212 | 31.7 milliseconds | Alpha Decay | 100.00% |
| Electron Capture | ~ 0.30% | ||
| 213 | 144 milliseconds | Alpha Decay | <= 100.00% |
| 214 | 87 milliseconds | Alpha Decay | 100.00% |
| 215 | 1.2 seconds | Alpha Decay | 100.00% |
| 216 | 26.0 milliseconds | Alpha Decay | 100.00% |
| Electron Capture | ~ 0.01% | ||
| 216m | 134 microseconds | Alpha Decay | 2.80% |
| Isomeric Transition | No Data Available | ||
| 217 | 0.241 milliseconds | Alpha Decay | 100.00% |
| 218 | 117 nanoseconds | Alpha Decay | 100.00% |
| 219 | 1.05 microseconds | Alpha Decay | 100.00% |
| 220 | 9.7 microseconds | Alpha Decay | 100.00% |
| Electron Capture | 2.0×10-7 % | ||
| 221 | 1.68 milliseconds | Alpha Decay | 100.00% |
| 222 | 2.8 milliseconds | Alpha Decay | 100.00% |
| 223 | 0.60 seconds | Alpha Decay | 100.00% |
| 224 | 0.81 seconds | Alpha Decay | 100.00% |
| 225 | 8.75 minutes | Electron Capture | ~ 10.00% |
| Alpha Decay | ~ 90.00% | ||
| 226 | 30.57 minutes | Alpha Decay | 100.00% |
| 227 | 18.68 days | Alpha Decay | 100.00% |
| 228 | 1.9116 years | Alpha Decay | 100.00% |
| Emission of an oxygen-20 nucleus | 1×10-11 % | ||
| 229 | 7932 years | Alpha Decay | 100.00% |
| 229m | 2 minutes | Isomeric Transition (suspected) | No Data Available |
| 230 | 7.54×10+4 years | Alpha Decay | 100.00% |
| Emission of a neon-24 nucleus | 6×10-11 % | ||
| Spontaneous Fission | <= 4×10-12 % | ||
| 231 | 25.52 hours | Alpha Decay | ~ 4×10-11 % |
| Beta-minus Decay | 100.00% | ||
| 232 | 1.40×1010 years | Alpha Decay | 100.00% |
| Spontaneous Fission | 1.1×10-9 % | ||
| 233 | 21.83 minutes | Beta-minus Decay | 100.00% |
| 234 | 24.10 days | Beta-minus Decay | 100.00% |
| 235 | 7.2 minutes | Beta-minus Decay | 100.00% |
| 236 | 37.3 minutes | Beta-minus Decay | 100.00% |
| 237 | 4.7 minutes | Beta-minus Decay | 100.00% |
| 238 | 9.4 minutes | Beta-minus Decay | 100.00% |
| 239 | No Data Available | No Data Available | No Data Available |
This page is maintained by Steve Gagnon.