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 |
| 197 | 100% | STABLE |
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 169 | No Data Available | Proton Emission (suspected) | No Data Available |
| Alpha Decay (suspected) | No Data Available | ||
| 170 | 286 microseconds | Proton Emission | 89.00% |
| Alpha Decay | 11.00% | ||
| 170m | 617 microseconds | Proton Emission | 58.00% |
| Alpha Decay | 42.00% | ||
| 171 | 17 microseconds | Proton Emission | 100.00% |
| Alpha Decay | No Data Available | ||
| 171m | 1.02 milliseconds | Alpha Decay | 54.00% |
| Proton Emission | 46.00% | ||
| 172 | 22 milliseconds | Alpha Decay | 100.00% |
| Electron Capture | No Data Available | ||
| Proton Emission | No Data Available | ||
| 172m | 7.7 milliseconds | Alpha Decay | 100.00% |
| Proton Emission | < 0.02% | ||
| Electron Capture | No Data Available | ||
| 173 | 25 milliseconds | Alpha Decay | 94.00% |
| Electron Capture | No Data Available | ||
| Proton Emission | No Data Available | ||
| 173m | 14.0 milliseconds | Alpha Decay | 92.00% |
| Proton Emission | No Data Available | ||
| Electron Capture | No Data Available | ||
| 174 | 139 milliseconds | Alpha Decay | > 0.00% |
| 175 | No Data Available | Electron Capture (suspected) | No Data Available |
| Alpha Decay (suspected) | No Data Available | ||
| 175m | 156 milliseconds | Alpha Decay | 94.00% |
| Electron Capture | 6.00% | ||
| 176 | No Data Available | No Data Available | No Data Available |
| 176m | 1.05 seconds | Alpha Decay | No Data Available |
| Electron Capture | No Data Available | ||
| 176m1 | 1.36 seconds | No Data Available | No Data Available |
| 177 | 1.53 seconds | Alpha Decay | 40.00% |
| Electron Capture | No Data Available | ||
| 177m | 1.00 seconds | Alpha Decay | 66.00% |
| Electron Capture | No Data Available | ||
| 178 | 2.6 seconds | Electron Capture | <= 60.00% |
| Alpha Decay | >= 40.00% | ||
| 179 | 7.1 seconds | Electron Capture | 78.00% |
| Alpha Decay | 22.00% | ||
| 180 | 8.1 seconds | Alpha Decay | >= 1.80% |
| Electron Capture | <= 98.20% | ||
| 181 | 13.7 seconds | Electron Capture | 97.30% |
| Alpha Decay | 2.70% | ||
| 182 | 15.5 seconds | Electron Capture | 99.87% |
| Alpha Decay | 0.13% | ||
| 183 | 42.8 seconds | Electron Capture | 99.45% |
| Alpha Decay | 0.55% | ||
| 184 | 20.6 seconds | Electron Capture | 100.00% |
| Alpha Decay | <= 0.02% | ||
| 184m | 47.6 seconds | Alpha Decay | <= 0.02% |
| Electron Capture | 70.00% | ||
| Isomeric Transition | 30.00% | ||
| 185 | 4.25 minutes | Electron Capture | 99.74% |
| Alpha Decay | 0.26% | ||
| 185m | 6.8 minutes | Electron Capture | < 100.00% |
| Isomeric Transition | No Data Available | ||
| 186 | 10.7 minutes | Electron Capture | 100.00% |
| Alpha Decay | 8.0×10-4 % | ||
| 187 | 8.3 minutes | Electron Capture | 100.00% |
| Alpha Decay | 3.0×10-3 % | ||
| 187m | 2.3 seconds | Isomeric Transition | 100.00% |
| 188 | 8.84 minutes | Electron Capture | 100.00% |
| 189 | 28.7 minutes | Electron Capture | 100.00% |
| Alpha Decay | < 3.0×10-5 % | ||
| 189m | 4.59 minutes | Electron Capture | 100.00% |
| 190 | 42.8 minutes | Electron Capture | 100.00% |
| Alpha Decay | < 1.0×10-6 % | ||
| 190m | 125 milliseconds | Isomeric Transition | 100.00% |
| 191 | 3.18 hours | Electron Capture | 100.00% |
| 191m | 0.92 seconds | Isomeric Transition | 100.00% |
| 192 | 4.94 hours | Electron Capture | 100.00% |
| 192m | 29 milliseconds | Isomeric Transition | 100.00% |
| 192m1 | 160 milliseconds | Isomeric Transition | 100.00% |
| 193 | 17.65 hours | Electron Capture | 100.00% |
| 193m | 3.9 seconds | Isomeric Transition | 99.97% |
| Electron Capture | ~ 0.03% | ||
| 194 | 38.02 hours | Electron Capture | 100.00% |
| 194m | 600 milliseconds | Isomeric Transition | 100.00% |
| 194m1 | 420 milliseconds | Isomeric Transition | 100.00% |
| 195 | 186.098 days | Electron Capture | 100.00% |
| 195m | 30.5 seconds | Isomeric Transition | 100.00% |
| 196 | 6.1669 days | Electron Capture | 93.00% |
| Beta-minus Decay | 7.00% | ||
| 196m | 8.1 seconds | Isomeric Transition | 100.00% |
| 196m1 | 9.6 hours | Isomeric Transition | 100.00% |
| 197 | STABLE | - | - |
| 197m | 7.73 seconds | Isomeric Transition | 100.00% |
| 198 | 2.6948 days | Beta-minus Decay | 100.00% |
| 198m | 2.272 days | Isomeric Transition | 100.00% |
| 199 | 3.139 days | Beta-minus Decay | 100.00% |
| 199m | 0.44 milliseconds | Isomeric Transition | 100.00% |
| 200 | 48.4 minutes | Beta-minus Decay | 100.00% |
| 200m | 18.7 hours | Isomeric Transition | 16.00% |
| Beta-minus Decay | 84.00% | ||
| 201 | 26.0 minutes | Beta-minus Decay | 100.00% |
| 202 | 28.4 seconds | Beta-minus Decay | 100.00% |
| 203 | 60 seconds | Beta-minus Decay | 100.00% |
| 204 | 39.8 seconds | Beta-minus Decay | 100.00% |
| 205 | 32.5 seconds | Beta-minus Decay | 100.00% |
| 205m | 6 seconds | Beta-minus Decay | No Data Available |
| Isomeric Transition | No Data Available | ||
| 206 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| 207 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available | ||
| 208 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available | ||
| 209 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available | ||
| 210 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available |
This page is maintained by Steve Gagnon.