| Proton | Neutron | Nuclear Spin | Energy State | |
|---|---|---|---|---|
| 225Np | 93 | 132 | -9/2 | |
| 226Np | 93 | 133 | -2 | |
| 227Np | 93 | 134 | -5/2 | |
| 228Np | 93 | 135 | 2 | |
| 229Np | 93 | 136 | 5/2 | |
| 230Np | 93 | 137 | 2 | |
| 231Np | 93 | 138 | 5/2 | |
| 232Np | 93 | 139 | 4 | |
| 233Np | 93 | 140 | 5/2 | |
| 234Np | 93 | 141 | 0 | |
| 235Np | 93 | 142 | 5/2 | |
| 236mNp | 93 | 143 | 1 | |
| 236Np | 93 | 143 | -6 | |
| 237Np | 93 | 144 | 5/2 | |
| 238Np | 93 | 145 | 2 | |
| 239Np | 93 | 146 | 5/2 | |
| 240Np | 93 | 147 | 5 | |
| 240mNp | 93 | 147 | 1 | |
| 241Np | 93 | 148 | 5/2 | |
| 242Np | 93 | 149 | 1 | |
| 242mNp | 93 | 149 | 6 | |
| 243Np | 93 | 150 | -5/2 | |
| 244Np | 93 | 151 | -7 |