Actinium is a silvery radioactive metallic element. Actinium glows in the dark due to its intense radioactivity with a blue light.
atomic number - 89
Atomic mass - 227 g.mol -1
Electronegativity - according to Pauling1.1
Density - 0.07 g.cm-3 at 20°C
Melting point 1050 °C
Boiling point 3250 °C