Which of the following has the highest lattice energy?

The lattice energies of $KF$,$KCl$,$KBr$ and $KI$ follow the order:

Which of the following is true for the compound $AB$,if it is formed by the transfer of an electron from $A$ to $B$?

The correct order of lattice energy of the following compounds is:

The electronic configurations of four elements $L$,$P$,$Q$,and $R$ are given as: $L (1s^2, 2s^2 2p^4)$; $Q (1s^2, 2s^2 2p^6, 3s^2 3p^5)$; $P (1s^2, 2s^2 2p^6, 3s^1)$; $R (1s^2, 2s^2 2p^6, 3s^2)$. The formulas of the ionic compounds that can be formed between these elements are:

Lattice energy of an ionic compound depends upon