88 Ra 226
Radium
Alkaline Earth Metal
Radium (Ra) is a chemical element with atomic number 88, classified as a alkaline earth metal. At room temperature it is a solid. It was discovered in 1898 by Marie and Pierre Curie.
Properties
- Atomic number
- 88
- Atomic mass
- 226 u
- Category
- Alkaline Earth Metal
- Group
- 2
- Period
- 7
- Block
- s-block
- Electron configuration
- [Rn] 7s²
- Phase at STP
- Solid
- Density
- 5.5 g/cm³
- Melting point
- 973 K (699.9 °C)
- Boiling point
- 2010 K (1736.8 °C)
- Electronegativity
- 0.9
- Atomic radius
- 283 pm
- Ionization energy
- 5.279 eV
- Discovery
- 1898 · Marie and Pierre Curie
Common uses
Cancer treatment, luminous paint, research
Did you know?
Discovered by Marie Curie and glows green in the dark.