Promethium

Lanthanide

Symbol: Pm

Atomic Number: 61

Standard State: Solid

Atomic Mass: 144.9128

Electron Configuration: [Xe]6s2 4f5

Electronegativity:

Atomic Radius: 236

Ionization Energy: 5.55

Melting Point: 1315

Boiling Point: 3273

Density: 7.26

Year Discovered: 1945