Fermium-257 (Fm-257)
Identity
- Protons
- 100
- Neutrons
- 157
- Mass number
- 257
- Mass
- 257.1 ± 4.7 u
- Mass excess
- 88.590 MeV
- Spin
- 9/2+
Stability
Half-life: 101 days
Natural occurrence
Not found in nature
Decays to
- alpha 99.8 % Cf-253
- spontaneous fission 0.21 %
Half-life: 101 days
Not found in nature