Np
Neptunium-221
Protons (Z)
93
Neutrons (N)
128
Mass number
221
Half-Life
30.0 ns
Abundance
---
Mass
221.032 u
Mass Excess
29,910.0 keV
Spin
(9/2-)
Discovered
---
Binding energy per nucleon
7,607 keV
Neutron separation energy
8,641 keV
Proton separation energy
389 keV
Decay Mode
- α→Protactinium-217
Decay chain
- NpNeptunium-221Z 93 · N 12830.0 ns
- α
- α100%
- α100%
- α89%
- β⁺90%
- β⁺99.96%
- β⁺100%
- EC100%