Which of the following is least ionic?

Which of the following substances has the least covalent character?

Which of the following statements about $LiCl$ and $NaCl$ is correct?

Describe the law of Fajan's rule.

Given below are two statements:
Statement $I$: The correct order in terms of bond dissociation enthalpy is $Cl_{2} > Br_{2} > F_{2} > I_{2}$.
Statement $II$: The correct trend in the covalent character of the metal halides is $[SnCl_{4} > SnCl_{2}]$, $[PbCl_{4} > PbCl_{2}]$ and $[UF_{4} > UF_{6}]$.
In the light of the above statements, choose the correct answer from the options given below:

How many of the following orders of covalent character are $TRUE$?
$(i)$ $LiF < LiCl < LiBr < LiI$ (Fajans' rule: covalent character increases with increasing size of anion)
$(ii)$ $CaCl_2 < FeCl_2 < FeCl_3$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iii)$ $Hg_2Cl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iv)$ $ZnCl_2 < CdCl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(v)$ $CuCl < AgCl < AuCl$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(vi)$ $AlN > Al_2O_3 > AlF_3$ (Fajans' rule: covalent character increases with increasing charge on anion)
$(vii)$ $CaF_2 < CaCl_2 < CaBr_2 < CaI_2$ (Fajans' rule: covalent character increases with increasing size of anion)