88 Ra
Alkaline earth metal
Radium
Glows in the dark.
Properties of Radium
- Atomic number (Z)
- 88
- Symbol
- Ra
- Atomic mass
- 226 g/mol
- Category
- Alkaline earth metal
- Group
- 2
- Period
- 7
- Electron configuration
- [Rn] 7s²
- Electronegativity (Pauling)
- 0.9
- Atomic radius
- 215 pm
- First ionization energy
- 509 kJ/mol
- Melting point
- 973 K (699.9 °C)
- Boiling point
- 2010 K (1736.8 °C)
- Density
- 5.5 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1898