NO. 088Alkaline Earth

Ra

Radium

Radium is a radioactive Alkaline Earth once used in luminous paints. Its intense radioactivity makes it hazardous, and it is now used mainly for research purposes.

Crystal Structure

Face-centered cubic

Technical Specifications

Atomic Mass226 u

Density5.5 g/cm³

Melting Point973 K

Boiling Point2010 K

Atomic Radius215 pm

Electronegativity0.9

Ionization Energy509 kJ/mol

Electron Affinity10 kJ/mol

Bonding TypeMetallic

Oxidation States2

Acid/BaseBasic

ReactivityHigh

Electron Configuration

[Rn] 7s2

Discovered ByMarie Curie

Year1898

Known Isotopes

Ra-226