Since radium belongs to alkaline earth metals, its oxide is basic in nature.
Physical properties of Radium
- Radium is the heaviest known alkaline earth metal and is the only radioactive member of its group. Its physical and chemical properties most closely resemble its lighter congener barium.
- Radium is a highly reactive metal and always exhibits its group oxidation state. It forms the colourless Ra2+ cation in aqueous solution, which is highly basic and doesn’t form complexes. Most radium compounds are therefore simple ionic compounds.