Most of the isotope data on this site has been obtained from the National Nuclear Data Center.
Naturally Occurring Isotopes
Curium has no naturally occurring isotopes.
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 233 | 23 seconds | Electron Capture | 80.00% |
| Alpha Decay | 20.00% | ||
| 234 | 51 seconds | Alpha Decay | ~ 40.00% |
| Spontaneous Fission | ~ 40.00% | ||
| Electron Capture | ~ 20.00% | ||
| 235 | No Data Available | Alpha Decay (suspected) | No Data Available |
| Electron Capture (suspected) | No Data Available | ||
| 236 | No Data Available | Electron Capture | No Data Available |
| Alpha Decay | No Data Available | ||
| 237 | No Data Available | Electron Capture | 100.00% |
| Alpha Decay | < 1.00% | ||
| 238 | 2.4 hours | Electron Capture | >= 90.00% |
| Alpha Decay | <= 10.00% | ||
| 239 | ≈ 2.9 hours | Electron Capture | 100.00% |
| Alpha Decay | < 0.10% | ||
| 240 | 27 days | Alpha Decay | > 99.50% |
| Electron Capture | < 0.50% | ||
| Spontaneous Fission | 3.9×10-6 % | ||
| 241 | 32.8 days | Electron Capture | 99.00% |
| Alpha Decay | 1.00% | ||
| 242 | 162.8 days | Alpha Decay | 100.00% |
| Spontaneous Fission | 6.2×10-6 % | ||
| Emission of a silicon-34 nucleus | 1×10-14 % | ||
| 243 | 29.1 years | Alpha Decay | 99.71% |
| Electron Capture | 0.29% | ||
| Spontaneous Fission | 5.3×10-9 % | ||
| 244 | 18.1 years | Spontaneous Fission | 1.4×10-4 % |
| Alpha Decay | 100.00% | ||
| 244m | 34 milliseconds | Isomeric Transition | 100.00% |
| 245 | 8423 years | Alpha Decay | 100.00% |
| Spontaneous Fission | 6.1×10-7 % | ||
| 246 | 4706 years | Alpha Decay | 99.97% |
| Spontaneous Fission | 0.03% | ||
| 247 | 1.56×10+7 years | Alpha Decay | 100.00% |
| 248 | 3.48×10+5 years | Alpha Decay | 91.61% |
| Spontaneous Fission | 8.39% | ||
| 249 | 64.15 minutes | Beta-minus Decay | 100.00% |
| 250 | ≈ 8.3×10+3 years | Spontaneous Fission | ~ 74.00% |
| Alpha Decay | ~ 18.00% | ||
| Beta-minus Decay | ~ 8.00% | ||
| 251 | 16.8 minutes | Beta-minus Decay | 100.00% |
| 252 | < 2 days | No Data Available | No Data Available |
This page is maintained by Steve Gagnon.