$A$ pink colored salt on dry heating becomes blue in colour. The salt may contain:

$A$ mixture of sodium oxide and calcium oxide is dissolved in water and saturated with excess carbon dioxide gas. The resulting solution is ...... It contains ......... :

Copper is very slowly oxidized on the surface in moist air,giving a green coating of verdigris. The chemical formula of verdigris is:

Which of the following statements is not correct?

Compare the alkali metals and alkaline earth metals with respect to $(i)$ ionization enthalpy,$(ii)$ basicity of oxides,and $(iii)$ solubility of hydroxides.

To distinguish between $A$ and $B$,it is observed that both elements form oxides,but $B$ also forms a nitride when burnt in air. What are $A$ and $B$?