| Atomic Mass | Mass Excess |
| 257.103060260468 amu | 96.0 MeV |
| Level energy (MeV) | Spin & parity | Half-life | Mode of decay | Branch ratio (%) | Decay energy (MeV) |
| Ground state | (1/2+) | 4.7 S 0.3 | A | <100.00 | 9.044 |
| Ground state | (1/2+) | 4.7 S 0.3 | SF | <=1.40 | 0 |
| Ground state | (1/2+) | 4.7 S 0.3 | EC | >0.00 | 0 |
| Ground state | 3.9 S 0.4 | A | <100.00 | 9.044 | |
| Ground state | 3.9 S 0.4 | SF | <=1.40 | 0 | |
| Ground state | 3.9 S 0.4 | EC | >0.00 | 0 |
There is no gamma-rays or the intensities are so weak!