Find the number of compounds which are more covalent in nature compared to ${\mathrm{AICl}}_3$ from the following.

${\mathrm{AlBr}}_3,{\mathrm{AlI}}_3,{\mathrm{BeCl}}_2,{\mathrm{BeBr}}_2,{\mathrm{AlF}}_3,{\mathrm{BeI}}_2$

[Given $\left.:r_{{\mathrm{Be}}^{2+}}:0.31\text{Å},r_{{\mathrm{Al}}^{3+}}:0.5\text{Å}\right]$

According to Fajan’s rule, large size of anion  and the small size of cation lead to  have  greater covalent character of the ionic bond. Hence, the  number of compounds which are more covalent in nature compared to ${\mathrm{AICl}}_3$ is ${\mathrm{AlBr}}_3,{\mathrm{AlI}}_3,{\mathrm{BeCl}}_2,{\mathrm{BeBr}}_2,{\mathrm{BeI}}_2$.