Cs
Caesium-121m
Protons (Z)
55
Neutrons (N)
66
Mass number
121
Half-Life
2.03 m
Abundance
---
Mass
120.917 u
Mass Excess
-77,034.0 keV
Spin
9/2+
Discovered
1981
Binding energy per nucleon
8,352 keV
Neutron separation energy
11,216 keV
Proton separation energy
2,151 keV
Decay Mode
Decay chain
- CsCaesium-121Z 55 · N 662.03 m
- β⁺83%
- β⁺100%
- β⁺100%
- β⁺100%