.Arrange the bonds in order of increasing ionic character in the molecules:LiF, K2O, N2, SO2and ClF3

ClF3 < SO2 < N2 < LiF < K2O

To determine the covalent character of a compound we us FAJANS rule.

The main points are:

1.)The size of anion should be larger

2.)The size of cation must be smaller

3.)The order of charges in both the cation as well as the anion must be larger.

4.)Pseudo configuratons(the one with incomplete octet but complete orbitals eg.Berryllium-it is not having complete octet but its last orbital i.e S is completely filled.)are to be considered as having more covalent character Noble(eg Neon gases.

On the basis of the above theroy you can predict the answers.