The correct sequence of increasing covalent character is represented by:
The correct sequence of increasing covalent character is represented by:
$\mathrm{LiCl} < \mathrm{NaCl} < \mathrm{BeCl}_2$
$\mathrm{BeCl}_2 < \mathrm{LiCl} < \mathrm{NaCl}$
$\mathrm{NaCl} < \mathrm{LiCl} < \mathrm{BeCl}_2$
$\mathrm{BeCl}_2 < \mathrm{NaCl} < \mathrm{LiCl}$
Solution
According to Fajan's Rule,
1. Smaller the size of cation, the larger the size of the anion, greater is the covalent character of the ionic bond.
2. Greater the charge of cation, greater is the covalent character of the ionic bond.
3. For cations with same charge and size, the one, with $(n-1) d^n n s^{\circ}$ which is found in transition elements have greater covalent character than the cation with $n s^2 n p^6$ electronic configuration, which is commonly found in alkali or alkaline earth metals.
Thus, order of covalent character is:
$\mathrm{NaCl} < \mathrm{LiCl} < \mathrm{BeCl}_2$
I Caution
Larger the anion, less is the effective nuclear charge that holds the valence electron of the ion in place. Since the last electron is loosely bound in large anions, it can easily be polarised by a cation, thereby making the compound more covalent.