[Click for Main Data] Proton Emission Neutron Emission Electron Emission Positron Emission
Most of the isotope data on this site has been obtained from the National Nuclear Data Center.
Naturally Occurring Isotopes
Radium has no naturally occurring isotopes.
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 201 | 1.6 milliseconds | Alpha Decay | 100.00% |
| Electron Capture | No Data Available | ||
| 202 | 16 milliseconds | Alpha Decay | 100.00% |
| 203 | 31 milliseconds | Alpha Decay | 100.00% |
| 203m | 24 milliseconds | Alpha Decay | 100.00% |
| 204 | 57 milliseconds | Alpha Decay | 100.00% |
| 205 | 210 milliseconds | Alpha Decay | <= 100.00% |
| Electron Capture | No Data Available | ||
| 205m | 170 milliseconds | Alpha Decay | <= 100.00% |
| Electron Capture | No Data Available | ||
| 206 | 0.24 seconds | Alpha Decay | 100.00% |
| 207 | 1.35 seconds | Alpha Decay | ~ 86.00% |
| Electron Capture | ~ 14.00% | ||
| 207m | 59 milliseconds | Isomeric Transition | >= 85.00% |
| Alpha Decay | <= 15.00% | ||
| 208 | 1.3 seconds | Alpha Decay | 95.00% |
| Electron Capture | 5.00% | ||
| 209 | 4.6 seconds | Alpha Decay | ~ 90.00% |
| Electron Capture | ~ 10.00% | ||
| 210 | 3.7 seconds | Alpha Decay | ~ 96.00% |
| Electron Capture | ~ 4.00% | ||
| 211 | 13 seconds | Alpha Decay | > 93.00% |
| Electron Capture | < 7.00% | ||
| 212 | 13.0 seconds | Alpha Decay | ~ 85.00% |
| Electron Capture | ~ 15.00% | ||
| 213 | 2.73 minutes | Alpha Decay | 80.00% |
| Electron Capture | 20.00% | ||
| 213m | 2.20 milliseconds | Isomeric Transition | ~ 99.40% |
| Alpha Decay | ~ 0.60% | ||
| 214 | 2.46 seconds | Alpha Decay | 99.94% |
| Electron Capture | 0.06% | ||
| 215 | 1.55 milliseconds | Alpha Decay | 100.00% |
| 216 | 182 nanoseconds | Alpha Decay | 100.00% |
| Electron Capture | < 1.0×10-8 % | ||
| 217 | 1.6 microseconds | Alpha Decay | 100.00% |
| 218 | 25.2 microseconds | Alpha Decay | 100.00% |
| 219 | 10 milliseconds | Alpha Decay | 100.00% |
| 220 | 18 milliseconds | Alpha Decay | 100.00% |
| 221 | 28 seconds | Alpha Decay | 100.00% |
| Emission of a carbon-14 nucleus | 1×10-12 % | ||
| 222 | 38.0 seconds | Alpha Decay | 100.00% |
| Emission of a carbon-14 nucleus | 3.0×10-8 % | ||
| 223 | 11.43 days | Alpha Decay | 100.00% |
| Emission of a carbon-14 nucleus | 8.9×10-8 % | ||
| 224 | 3.6319 days | Alpha Decay | 100.00% |
| Emission of a carbon-14 nucleus | 4.0×10-9 % | ||
| 225 | 14.9 days | Beta-minus Decay | 100.00% |
| 226 | 1600 years | Alpha Decay | 100.00% |
| Emission of a carbon-14 nucleus | 3.2×10-9 % | ||
| 227 | 42.2 minutes | Beta-minus Decay | 100.00% |
| 228 | 5.75 years | Beta-minus Decay | 100.00% |
| 229 | 4.0 minutes | Beta-minus Decay | No Data Available |
| 230 | 93 minutes | Beta-minus Decay | 100.00% |
| 231 | 104.1 seconds | Beta-minus Decay | 100.00% |
| 232 | 4.2 minutes | Beta-minus Decay | 100.00% |
| 233 | 30 seconds | Beta-minus Decay | 100.00% |
| 234 | 30 seconds | Beta-minus Decay | 100.00% |
| 235 | No Data Available | No Data Available | No Data Available |
This page is maintained by Steve Gagnon.