Neptunium-237 (Np-237)
Identity
- Protons
- 93
- Neutrons
- 144
- Mass number
- 237
- Mass
- 237.0 ± 1.2 u
- Mass excess
- 44.872 MeV
- Spin
- 5/2+*
Stability
Half-life: 2.14 × 10⁶ years
Natural occurrence
Not found in nature
Decays to
- alpha 100.0 % Pa-233
- spontaneous fission 2.0e-10 %