Pm
61 lanthanide Generated with AI
Promethium
Symbol Pm
Atomic Mass 145
Promethium, originally prometheum, is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is one of only two such elements that are followed in the periodic table by elements with stable forms, a distinction shared with technetium. Chemically, promethium is a lanthanide, which forms salts when combined with other elements.
Properties
- Phase: Solid
- Density: 7.26 g/cm³
- Melting Point: 1315 K
- Boiling Point: 3273 K