Radium was discovered by Marie Sklodowska-Curie and her husband Pierre on December 21, 1898 in a uraninite sample.
Name: Radium Symbol: Ra Atomic number: 88 Atomic weight: 226.03 State: solid Group, period, block: 2, 7, s Color: silvery white metallic Classification: alkaline earth metal Electron configuration: 7s2
Density: 5.5 g/cm-3 Melting point: 973 K,700 °C,1292 °F Boiling point: 2010 K,1737 °C,3158.6 °F
Oxidation states: 2 Electronegativity: 0.9 (Pauling scale) Ionization energies: 1st: 509.3 kJ·mol-1 Covalent radius: 221±2 pm Van der Waals radius: 283 pm
There are four naturally occurring isotopes of radium exist, 223Ra, 224Ra, 226Ra, and 228Ra.