Promethium
Atomic number
61
Atomic weight
145
Discovery (year)
1945
Atomic radius (A)
1.8
Melting point (
o
C)
Boiling point (
o
C)
Density (g/cm
3
)
Specific heat (cal/g
o
C)
Ionization potential (eV)
5.55
Electron Affinity (eV)
