Match the following compounds (Column-I) with their uses (Column-II) :

S.No.	Column-I	S.No.	Column-II
(I)	Ca(OH)2	(A)	casts of statues
(II)	NaCl	(B)	white wash
(III)	CaSO4, $${1 \over 2}$$H2O	(C)	antacid
(IV)	CaCO3	(D)	washing soda preparation

Among the sulphates of alkaline earth metals, the solubilities of BeSO₄ and MgSO₄ in water, respectively, are :

An alkaline earth metal ‘M’ readily forms water soluble sulphate and water insoluble hydroxide. Its oxide MO is very stable to heat and does not have rock-salt structure. M is :

On combustion of Li, Na and K in excess of air, the major oxides formed, respectively, are :