| Proton number | Neutron number | Nucleon number | Symbol | Name |
| 91 | 140 | 231 | Pa | Protoactinium |
| 92 | 146 | 238 | U | Uranium |
| 93 | 144 | 237 | Np | Neptunium |
| 94 | 148 | 242 | Pu | Plutonium |
| 95 | 146 | 243 | Am | Americium |
| 96 | 152 | 248 | Cm | Curium |
| 97 | 150 | 247 | Bk | Berkelium |
| 98 | 151 | 249 | Cf | Californium |
| 99 | 154 | 253 | Es | Einsteinium |
| 100 | 153 | 253 | Po | Fermium |
| 101 | 152 | 253 | Md | Mendelevium |
| 102 | 151 | 253 | Ra | Nobelium |
| 103 | 151 | 254 | Ac | Lawrencium |