Pm
Promethium-129
Protons (Z)
61
Neutrons (N)
68
Mass number
129
Half-Life
2.4 s
Abundance
---
Mass
128.943 u
Mass Excess
-53,180.0 keV
Spin
(5/2+)
Discovered
2004
Binding energy per nucleon
8,114 keV
Neutron separation energy
13,031 keV
Proton separation energy
-61 keV
Decay Mode
Decay chain
- PmPromethium-129Z 61 · N 682.4 s
- β⁺100%
- β⁺100%
- β⁺100%
- β⁺100%
- β⁺100%
- β⁺100%
- β⁺100%