Pm

Promethium-138

Protons (Z)

61

Neutrons (N)

77

Mass number

138

Half-Life

3.24 m

Abundance

---

Mass

137.92 u

Mass Excess

-74,914.0 keV

Spin

(3-)

Discovered

1973

Binding energy per nucleon

8,268 keV

Neutron separation energy

8,912 keV

Proton separation energy

2,619 keV

Decay Mode

β⁺Neodymium-138100%

Decay chain

Promethium-138Z 61 · N 773.24 m
β⁺100%
β⁺100%
β⁺100%