Arrange the following in increasing order of their covalent character.
(A) $$CaF_2$$
(B) $$CaCl_2$$
(C) $$CaBr_2$$
(D) $$CaI_2$$
Choose the correct answer from the options given below.

We need to arrange $$CaF_2$$, $$CaCl_2$$, $$CaBr_2$$, and $$CaI_2$$ in increasing order of covalent character.

Applying Fajans' Rules:

According to Fajans' rules, the covalent character of an ionic compound increases when:

1. The cation has a small size and high charge (greater polarizing power)

2. The anion has a large size and high charge (greater polarizability)

Here, the cation ($$Ca^{2+}$$) is the same in all compounds. The difference lies in the anions.

Comparing the anions by size:

$$F^- < Cl^- < Br^- < I^-$$

As the size of the anion increases, it becomes more easily polarized by the cation. A more polarized anion leads to greater sharing of electron density, which means greater covalent character.

Therefore, the increasing order of covalent character is:

$$CaF_2 < CaCl_2 < CaBr_2 < CaI_2$$

$$A < B < C < D$$

The correct answer is Option B.