What happens when:
$(i)$ Concentrated $H_2SO_4$ is added to calcium fluoride
$(ii)$ $SO_3$ is passed through water?

Among chalcogens,the correct order of amount of energy released during electron gain (electron gain enthalpy) is

Assertion: $Ozone$ is a powerful oxidising agent in comparison to $O_2$.
Reason: $Ozone$ is diamagnetic but $O_2$ is paramagnetic.

Upon heating $KClO_3$ in the presence of a catalytic amount of $MnO_2$,a gas $W$ is formed. Excess amount of $W$ reacts with white phosphorus to give $X$. The reaction of $X$ with $HNO_3$ gives $Y$ and $Z$.
$(1)$ $W$ and $X$ are,respectively:
$[A]$ $O_3$ and $P_4O_6$
$[B]$ $O_2$ and $P_4O_6$
$[C]$ $O_2$ and $P_4O_{10}$
$[D]$ $O_3$ and $P_4O_{10}$
$(2)$ $Y$ and $Z$ are,respectively:
$[A]$ $N_2O_3$ and $H_3PO_4$
$[B]$ $N_2O_5$ and $HPO_3$
$[C]$ $N_2O_4$ and $HPO_3$
$[D]$ $N_2O_4$ and $H_3PO_3$
Give the answer of question $(1)$ and $(2)$.

Choose the $CORRECT$ statement.

The thermal stability of the hydrides of group-$16$ elements follows the order: