Which statement concerning the oxides and hydroxides of the Group II elements Mg, Ca, Sr and Ba is correct?
- AEach of the oxides reacts readily with water to form a solution of pH 12 or above.
- BMagnesium oxide is used as a furnace lining because it has a giant molecular structure and hence a high melting point.
- CThe hydroxides are produced directly by the thermal decomposition of the corresponding nitrates.
- DThe solubility of the hydroxides increases from Mg(OH)$_2$ to Ba(OH)$_2$.