Why does molten sodium chloride conduct electricity?

Which of the following can conduct electricity in the fused state?

The lattice energy of the lithium halides is in the following order:

Consider the Born-Haber cycle for the formation of an ionic compound given below and identify the compound $Z$ formed.
$M_{(s)}$ $\xrightarrow{\Delta H_1} M_{(g)}$ $\xrightarrow{\Delta H_2} M^{+}_{(g)}$
$\frac{1}{2} X_{2(g)}$ $\xrightarrow{\Delta H_3} X_{(g)}$ $\xrightarrow{\Delta H_4} X^{-}_{(g)}$
$M^{+}_{(g)} + X^{-}_{(g)} \xrightarrow{\Delta H_5} Z$

Among the following,which one has the highest cation to anion size ratio?

In the formation of $NaCl$ from $Na$ and $Cl$,which of the following occurs?