Name: Promethium
Symbol: Pm
Atomic Number: 61
AtomicWeight: 145.000000
Family: Lanthanides
CAS RN: 7440-12-2
Description: A radioactive rare earth metal, metallic in appearance
State (25 °C): Solid
Melting Point: 1315 °K
Boiling Point: 3273 °K
Density: 7.26 g/cm³
Oxidation states: +3
Electron Configuration: [Xe] 4f⁵6s²
Radius: 185 pm (Covalent)
Electronegativity: 1.13 (Pauling Scale)

1st Ionization Energy: 540 KJ/mole
2nd Ionization Energy: 1050 KJ/mole
3rd Ionization Energy: 2150 KJ/mole