It's Elemental
Isotopes of the Element Astatine
Astatine
Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information.
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 191 | 1.7 milliseconds | Alpha Decay | 100.00% |
| 191m | 2.1 milliseconds | Alpha Decay | 100.00% |
| 192 | 11.5 milliseconds | Alpha Decay | 100.00% |
| 192m | 88 milliseconds | Alpha Decay | 100.00% |
| 193 | 28 milliseconds | Alpha Decay | 100.00% |
| 193m | 21 milliseconds | Alpha Decay | 100.00% |
| 193m1 | 27 milliseconds | Alpha Decay | 24.00% |
| Isomeric Transition | 76.00% | ||
| 194 | 310 milliseconds | Alpha Decay | No Data Available |
| 194m | 253 milliseconds | Alpha Decay | No Data Available |
| 195 | 328 milliseconds | Alpha Decay | 100.00% |
| 195m | 147 milliseconds | Alpha Decay | 100.00% |
| 196 | 0.388 seconds | Alpha Decay | ~ 95.10% |
| Electron Capture | ~ 4.90% | ||
| 197 | 0.388 seconds | Alpha Decay | 96.10% |
| Electron Capture | 3.90% | ||
| 197m | 2.0 seconds | Electron Capture | No Data Available |
| Isomeric Transition | <= 4.0×10-3 % | ||
| Alpha Decay | <= 100.00% | ||
| 198 | 3.8 seconds | Alpha Decay | 90.00% |
| Electron Capture | 10.00% | ||
| 198m | 1.04 seconds | Alpha Decay | 84.00% |
| Electron Capture | 16.00% | ||
| 199 | 7.03 seconds | Alpha Decay | 90.00% |
| Electron Capture | 10.00% | ||
| 200 | 43 seconds | Alpha Decay | 52.00% |
| Electron Capture | 48.00% | ||
| 200m | 47 seconds | Alpha Decay | 43.00% |
| Electron Capture | <= 57.00% | ||
| 200m1 | 7.3 seconds | Electron Capture | < 89.50% |
| Isomeric Transition | < 89.50% | ||
| Alpha Decay | ~ 10.50% | ||
| 201 | 85.2 seconds | Alpha Decay | 71.00% |
| Electron Capture | 29.00% | ||
| 202 | 184 seconds | Electron Capture | 63.00% |
| Alpha Decay | 37.00% | ||
| 202m | 182 seconds | Electron Capture | 91.30% |
| Alpha Decay | 8.70% | ||
| 202m1 | 0.46 seconds | Alpha Decay | 0.10% |
| Isomeric Transition | 99.90% | ||
| 203 | 7.4 minutes | Electron Capture | 69.00% |
| Alpha Decay | 31.00% | ||
| 204 | 9.12 minutes | Electron Capture | 96.09% |
| Alpha Decay | 3.91% | ||
| 204m | 108 milliseconds | Isomeric Transition | 100.00% |
| 205 | 26.9 minutes | Electron Capture | 90.00% |
| Alpha Decay | 10.00% | ||
| 206 | 30.6 minutes | Electron Capture | 99.10% |
| Alpha Decay | 0.90% | ||
| 207 | 1.81 hours | Electron Capture | 91.40% |
| Alpha Decay | 8.60% | ||
| 208 | 1.63 hours | Electron Capture | 99.45% |
| Alpha Decay | 0.55% | ||
| 209 | 5.41 hours | Electron Capture | 95.90% |
| Alpha Decay | 4.10% | ||
| 210 | 8.1 hours | Electron Capture | 99.82% |
| Alpha Decay | 0.18% | ||
| 211 | 7.214 hours | Electron Capture | 58.20% |
| Alpha Decay | 41.80% | ||
| 212 | 0.314 seconds | Electron Capture | < 0.03% |
| Beta-minus Decay | < 2.0×10-6 % | ||
| Alpha Decay | 100.00% | ||
| 212m | 0.119 seconds | Alpha Decay | > 99.00% |
| Isomeric Transition | < 1.00% | ||
| 213 | 125 nanoseconds | Alpha Decay | 100.00% |
| 214 | 558 nanoseconds | Alpha Decay | 100.00% |
| 215 | 0.10 milliseconds | Alpha Decay | 100.00% |
| 216 | 0.30 milliseconds | Alpha Decay | 100.00% |
| Beta-minus Decay | < 6.0×10-3 % | ||
| Electron Capture | < 3.0×10-7 % | ||
| 217 | 32.3 milliseconds | Beta-minus Decay | 7.0×10-3 % |
| Alpha Decay | 99.99% | ||
| 218 | 1.5 seconds | Alpha Decay | 99.90% |
| Beta-minus Decay | 0.10% | ||
| 219 | 56 seconds | Alpha Decay | ~ 97.00% |
| Beta-minus Decay | ~ 3.00% | ||
| 220 | 3.71 minutes | Alpha Decay | 8.00% |
| Beta-minus Decay | 92.00% | ||
| 221 | 2.3 minutes | Beta-minus Decay | 100.00% |
| 222 | 54 seconds | Beta-minus Decay | 100.00% |
| 223 | 50 seconds | Beta-minus Decay | 100.00% |
| 224 | 76 seconds | Beta-minus Decay (suspected) | No Data Available |
| 225 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| 226 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| 227 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| 228 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| 229 | > 300 nanoseconds | Beta-minus Decay | No Data Available |
| Beta-minus Decay with delayed Neutron Emission | No Data Available |
Citation and linking information
For questions about this page, please contact Carol McKisson.