Answer: KI, LiBr, MgS,GaN
Explanation:
Ionic sizes are the deciding factor in lattice energy. The smaller the ion, the higher the lattice energy. Since K+> Li+ and I- is larger than Br-, LiBr will have a higher lattice energy. The size of the sulphide ion is much smaller than the nitride ion but the Gallium is much smaller due to lanthanide contraction hence the answer.