The melting point of $RbBr$ is $682\,^{\circ}C$ while that of $NaF$ is $988\,^{\circ}C$. The principal reason for this fact is

Given below are two statements:
Assertion $(A)$: Ionic compounds are formed by non-directional bonds.
Reasoning $(R)$: They are soluble in nonpolar solvents.
The correct answer is:

Elements $X$ and $Y$ have $2$ and $6$ electrons in their valence shells,respectively. If they combine,what will be the possible formula of the compound formed?

The lattice energy of an ionic compound depends on which of the following?

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

The Born-Haber cycle for $KCl$ is evaluated with the following data:
$\Delta_{f} H^{\ominus}$ for $KCl = -436.7 \ kJ \ mol^{-1}$
$\Delta_{sub} H^{\ominus}$ for $K = 89.2 \ kJ \ mol^{-1}$
$\Delta_{ionization} H^{\ominus}$ for $K = 419.0 \ kJ \ mol^{-1}$
$\Delta_{electron \ gain} H^{\ominus}$ for $Cl_{(g)} = -348.6 \ kJ \ mol^{-1}$
$\Delta_{bond} H^{\ominus}$ for $Cl_2 = 243.0 \ kJ \ mol^{-1}$
The magnitude of lattice enthalpy of $KCl$ in $kJ \ mol^{-1}$ is ..... . (Nearest integer)