Which of the following compounds has the least ionic character?

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)

Which of the following is the correct decreasing order of the melting points of calcium halides?

Why is $LiF$ almost insoluble in water whereas $LiCl$ soluble not only in water but also in acetone?

Identify the correct order of solubility in aqueous medium.

The charge/size ratio of a cation determines its polarizing power. Which one of the following sequences represents the increasing order of the polarizing power of the cationic species,$K^{+}, Ca^{2+}, Mg^{2+}, Be^{2+}$?