In which of the following compounds is the ratio of the size of the anion to the cation the smallest?

Out of the following,which compound will have electrovalent bonding?

Magnesium reacts with an element $(X)$ to form an ionic compound. If the ground state electronic configuration of $(X)$ is $1s^{2} 2s^{2} 2p^{3},$ the simplest formula for this compound is

An ionic bond $P^{+} Q^{-}$ is most likely to be formed when

Among the following compounds,the one with the highest lattice energy is

Describe the steps involved in the formation of an ionic bond and the associated energy changes.