Pm
Promethium-139
Protons (Z)
61
Neutrons (N)
78
Mass number
139
Half-Life
4.15 m
Abundance
---
Mass
138.917 u
Mass Excess
-77,501.0 keV
Spin
(5/2+)
Discovered
1967
Binding energy per nucleon
8,286 keV
Neutron separation energy
10,658 keV
Proton separation energy
2,773 keV
Decay Mode
- β⁺→Neodymium-139100%
Decay chain
- PmPromethium-139Z 61 · N 784.15 m
- β⁺100%
- β⁺100%
- β⁺100%
- EC100%