Arrange the bonds in order of increasing ionic character in the molecules

Arrange the bonds in order of increasing ionic character in the molecules; LiF , ${ K }{ 2 }O$,
${ N }
{ 2 }$,
${ SO }{ 2 }$ and
${Cl F }
{ 3 }$.

Ionic character ∝ lattice energy ∝ 1/ size of ion ∝ charge on ion
A non-polar molecule like { N }_{ 2 } has almost negligible ionic character.
.’. The order of ionic character is