| Proton | Neutron | Nuclear Spin | Energy State | |
|---|---|---|---|---|
| 237Cf | 98 | 139 | 5/2 | |
| 238Cf | 98 | 140 | 0 | |
| 239Cf | 98 | 141 | 5/2 | |
| 240Cf | 98 | 142 | 0 | |
| 241Cf | 98 | 143 | -7/2 | |
| 242Cf | 98 | 144 | 0 | |
| 243Cf | 98 | 145 | 1/2 | |
| 244Cf | 98 | 146 | 0 | |
| 245Cf | 98 | 147 | 5/2 | |
| 246Cf | 98 | 148 | 0 | |
| 247Cf | 98 | 149 | 7/2 | |
| 248Cf | 98 | 150 | 0 | |
| 249Cf | 98 | 151 | -9/2 | |
| 249mCf | 98 | 151 | 5/2 | |
| 250Cf | 98 | 152 | 0 | |
| 251Cf | 98 | 153 | 1/2 | |
| 252Cf | 98 | 154 | 0 | |
| 253Cf | 98 | 155 | 7/2 | |
| 254Cf | 98 | 156 | 0 | |
| 255Cf | 98 | 157 | 7/2 | |
| 256Cf | 98 | 158 | 0 |