Atomic number 88
Radium
Alkaline earth metal
Quick facts
- Atomic mass
- 226.00
- Group
- 2
- Period
- 7
- State (STP)
- solid
- Electronegativity
- 0.90
- Common ox. states
- +2
Properties
Electron configuration
[Rn] 7s²
- Ionization energy
- 509.3 kJ/mol
- Electron affinity
- 9.6 kJ/mol
- Melting point
- 973.00 K (699.9 °C)
- Boiling point
- 2010.00 K (1736.8 °C)
How it bonds
Radium parallels barium: Ra²⁺ in salts, glows in the dark from its own radioactive decay. Marie Curie's discovery; the early 20th-century glow-in-the-dark watch dials that poisoned the 'Radium Girls' factory workers used radium-226.