Cs

Caesium-138m

Protons (Z)

55

Neutrons (N)

83

Mass number

138

Half-Life

2.91 m

Abundance

---

Mass

137.911 u

Mass Excess

-82,807.0 keV

Spin

6-

Discovered

1971

Binding energy per nucleon

8,360 keV

Neutron separation energy

4,333 keV

Proton separation energy

7,713 keV

Decay Mode

Decay chain

Caesium-138Z 55 · N 832.91 m
γ81%
β⁻100%