Which pair is not correct order of lattice energy?

Larger the charge on cation and anion, larger the polarising power and thus larger the covalent nature and such compounds have larger lattice energy.K+>Mg2+  size  Cl−> O2−  size  +1    +2        charge     −1  <  2−     charge Thus, MgO is less ionic than KCI thus lattice energy of MgOis larger than that of KCl.Thus, given order is incorrect.