Which of the following compounds gives oxygen on fast heating?
$I$. $AgNO_3$
$II$. $CaCO_3$
$III$. $Pb(NO_3)_2$
$IV$. $Na_2CO_3$

Select the correct statement.

Which of the following electronic configurations belongs to $s-$block elements?

Which of the following order$(s)$ is/are correct?
$(A)$ Thermal stability: $BeSO_4 < MgSO_4 < CaSO_4 < SrSO_4$
$(B)$ Melting point: $NaCl > KCl > RbCl > CsCl$
$(C)$ Solubility: $LiOH < NaOH$
$(D)$ Lattice energy: $KF > KCl > KBr > KI$

White vitriol is .......

Match List-$I$ with List-$II$ :

List-$I$ (Elements)	List-$II$ (Properties)
$(a)$ $Ba$	$(i)$ Organic solvent soluble compounds
$(b)$ $Ca$	$(ii)$ Outer electronic configuration $6s^2$
$(c)$ $Li$	$(iii)$ Oxalate insoluble in water
$(d)$ $Na$	$(iv)$ Formation of very strong monoacidic base

Choose the correct answer from the options given below :