61
Pm
Promethium
Lanthanide period 6 f-block discovered: 1945
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 61
- Atomic mass
- 144.91276 a.m.u.
- Electron configuration
- [Xe]6s2 4f5
- Atomic radius
- 236 pm
- Ionization energy
- 5.55 eV
- Oxidation states
- +3
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 1315 K (1 041,85 °C)
- Boiling point
- 3273 K (2 999,85 °C)
- Density
- 7.26 g/cm³