Match List - I with List - II.

	List I (Salt)		List II (Flame colour wavelength)
(a)	LiCl	(i)	455.5 nm
(b)	NaCl	(ii)	670.8 nm
(c)	RbCl	(iii)	780.0 nm
(d)	CsCl	(iv)	589.2 nm

Choose the correct answer from the options given below :

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 :