Science Education
Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information.
Naturally Occurring Isotopes
Nobelium has no naturally occurring isotopes.
Known Isotopes
| Mass Number | Half-life | Decay Mode | Branching Percentage |
| 248 | 2 microseconds | Spontaneous Fission (suspected) | No Data Available |
| 249 | No Data Available | No Data Available | No Data Available |
| 250 | 4.2 microseconds | Spontaneous Fission | 100.00% |
| Alpha Decay | < 2.00% | ||
| 251 | 0.80 seconds | Alpha Decay | 84.00% |
| Spontaneous Fission | < 0.30% | ||
| Electron Capture | No Data Available | ||
| 251m | 1.02 seconds | Alpha Decay | 100.00% |
| 252 | 2.47 seconds | Alpha Decay | 70.70% |
| Spontaneous Fission | 29.30% | ||
| Electron Capture | < 1.10% | ||
| 252m | 110 milliseconds | Isomeric Transition | 100.10% |
| 253 | 1.62 minutes | Electron Capture | No Data Available |
| Alpha Decay | ~ 80.00% | ||
| 254 | 51 seconds | Alpha Decay | 90.00% |
| Electron Capture | 10.00% | ||
| Spontaneous Fission | 0.17% | ||
| 254m | 0.28 seconds | Isomeric Transition | > 80.00% |
| 255 | 3.52 minutes | Electron Capture | 70.00% |
| Alpha Decay | 30.00% | ||
| 256 | 2.91 seconds | Alpha Decay | 99.47% |
| Spontaneous Fission | 0.53% | ||
| 257 | 25 seconds | Alpha Decay | <= 100.00% |
| Spontaneous Fission | <= 1.50% | ||
| 258 | 1.2 milliseconds | Spontaneous Fission | <= 100.00% |
| 259 | 58 minutes | Alpha Decay | 75.00% |
| Electron Capture | 25.00% | ||
| Spontaneous Fission | < 10.00% | ||
| 260 | 106 milliseconds | Spontaneous Fission | 100.00% |
| 261 | No Data Available | Alpha Decay (suspected) | No Data Available |
| 262 | ≈ 5 milliseconds | Spontaneous Fission | 100.00% |
| 263 | No Data Available | Alpha Decay (suspected) | No Data Available |
| Spontaneous Fission (suspected) | No Data Available | ||
| 264 | No Data Available | Alpha Decay (suspected) | No Data Available |
This page is maintained by Steve Gagnon.
