Fr
Francium-221
Protons (Z)
87
Neutrons (N)
134
Mass number
221
Half-Life
4.8 m
Abundance
---
Mass
221.014 u
Mass Excess
13,277.0 keV
Spin
5/2-
Discovered
1947
Binding energy per nucleon
7,703 keV
Neutron separation energy
6,276 keV
Proton separation energy
4,624 keV
Decay Mode
Decay chain
- FrFrancium-221Z 87 · N 1344.8 m
- α~100%
- α99.992%
- β⁻97.91%
- α100%
- β⁻100%
- α100%