It's Elemental
Isotopes of the Element Thallium
Thallium
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 |
| 203 | 29.524% | STABLE |
| 205 | 70.48% | STABLE |
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 176 | 5.2 milliseconds | Proton Emission | 100.00% |
| 177 | 18 milliseconds | Alpha Decay | 73.00% |
| Proton Emission | 27.00% | ||
| 178 | 254 milliseconds | Alpha Decay | ~ 53.00% |
| Electron Capture | ~ 47.00% | ||
| 179 | 0.23 seconds | Alpha Decay | < 100.00% |
| Electron Capture | No Data Available | ||
| Proton Emission | No Data Available | ||
| 179m | 1.5 milliseconds | Electron Capture | No Data Available |
| Isomeric Transition | No Data Available | ||
| Alpha Decay | <= 100.00% | ||
| Proton Emission | No Data Available | ||
| 180 | 1.09 seconds | Electron Capture | 94.00% |
| Alpha Decay | 6.00% | ||
| Electron Capture with delayed Spontaneous Fission | ~ 1.0×10-4 % | ||
| 181 | 3.2 seconds | Electron Capture | No Data Available |
| Alpha Decay | <= 10.00% | ||
| 181m | 1.40 milliseconds | Isomeric Transition | 99.60% |
| Alpha Decay | 0.40% | ||
| 182 | 3.1 seconds | Electron Capture | 97.50% |
| Alpha Decay | < 5.00% | ||
| 183 | 6.9 seconds | Alpha Decay | No Data Available |
| Electron Capture | > 0.00% | ||
| 183m | 53.3 milliseconds | Isomeric Transition | No Data Available |
| Electron Capture | No Data Available | ||
| Alpha Decay | 2.00% | ||
| 184 | 10.1 seconds | Electron Capture | 97.90% |
| Alpha Decay | 2.10% | ||
| 185 | 19.5 seconds | Electron Capture | No Data Available |
| 185m | 1.93 seconds | Alpha Decay | No Data Available |
| Isomeric Transition | No Data Available | ||
| 186 | 27.5 seconds | Alpha Decay | ~ 6.0×10-3 % |
| Electron Capture | 100.00% | ||
| 186m | 2.9 seconds | Isomeric Transition | 100.00% |
| 187 | ≈ 51 seconds | Electron Capture | 100.00% |
| Alpha Decay | ~ 0.03% | ||
| 187m | 15.60 seconds | Electron Capture | < 99.90% |
| Isomeric Transition | < 99.90% | ||
| Alpha Decay | 0.15% | ||
| 188 | 71 seconds | Electron Capture | 100.00% |
| Electron Capture | 100.00% | ||
| 188m | 41 milliseconds | Electron Capture | No Data Available |
| Isomeric Transition | 100.00% | ||
| 189 | 2.3 minutes | Electron Capture | 100.00% |
| 189m | 1.4 minutes | Electron Capture | < 100.00% |
| Isomeric Transition | < 4.00% | ||
| 190 | 2.6 minutes | Electron Capture | 100.00% |
| 190m | 3.7 minutes | Electron Capture | 100.00% |
| 190m1 | 0.75 milliseconds | Isomeric Transition | 100.00% |
| 191 | No Data Available | No Data Available | No Data Available |
| 191m | 5.22 minutes | No Data Available | No Data Available |
| 192 | 9.6 minutes | Electron Capture | 100.00% |
| 192m | 10.8 minutes | Electron Capture | 100.00% |
| 193 | 21.6 minutes | Electron Capture | 100.00% |
| 193m | 2.11 minutes | Isomeric Transition | <= 75.00% |
| Electron Capture | >= 25.00% | ||
| 194 | 33.0 minutes | Electron Capture | 100.00% |
| Alpha Decay | < 1.0×10-7 % | ||
| 194m | 32.8 minutes | Electron Capture | 100.00% |
| 195 | 1.16 hours | Electron Capture | 100.00% |
| 195m | 3.6 seconds | Isomeric Transition | 100.00% |
| 196 | 1.84 hours | Electron Capture | 100.00% |
| 196m | 1.41 hours | Electron Capture | 96.20% |
| Isomeric Transition | 3.80% | ||
| 197 | 2.84 hours | Electron Capture | 100.00% |
| 197m | 0.54 seconds | Isomeric Transition | 100.00% |
| 198 | 5.3 hours | Electron Capture | 100.00% |
| 198m | 1.87 hours | Electron Capture | 55.90% |
| Isomeric Transition | 44.10% | ||
| 198m1 | 32.1 milliseconds | Isomeric Transition | 100.00% |
| 199 | 7.42 hours | Electron Capture | 100.00% |
| 199m | 28.4 milliseconds | Isomeric Transition | 100.00% |
| 200 | 26.1 hours | Electron Capture | 100.00% |
| 200m | 34.0 milliseconds | Isomeric Transition | 100.00% |
| 201 | 3.0421 days | Electron Capture | 100.00% |
| 201m | 2.01 milliseconds | Isomeric Transition | 100.00% |
| 202 | 12.31 days | Electron Capture | 100.00% |
| 203 | STABLE | - | - |
| 204 | 3.783 years | Beta-minus Decay | 97.08% |
| Electron Capture | 2.92% | ||
| 205 | STABLE | - | - |
| 206 | 4.202 minutes | Beta-minus Decay | 100.00% |
| 206m | 3.74 minutes | Isomeric Transition | 100.00% |
| 207 | 4.77 minutes | Beta-minus Decay | 100.00% |
| 207m | 1.33 seconds | Isomeric Transition | 100.00% |
| 208 | 3.053 minutes | Beta-minus Decay | 100.00% |
| 209 | 2.161 minutes | Beta-minus Decay | 100.00% |
| 210 | 1.30 minutes | Beta-minus Decay | 100.00% |
| Beta-minus Decay with delayed Neutron Emission | 7.0×10-3 % | ||
| 211 | > 300 nanoseconds | Beta-minus Decay (suspected) | No Data Available |
| 212 | > 300 nanoseconds | Beta-minus Decay (suspected) | No Data Available |
| 213 | 101 seconds | Beta-minus Decay | No Data Available |
| 214 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available | ||
| 215 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available | ||
| 216 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available | ||
| 217 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available |
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