I have a doubt about which one has the biggest covalent character
I think LiF because:
-Li more electronegative than Cs
-Li+ has a bigger charge density than Cs so it can polarize F- easily (more bond character)
BUT if I think at the Pearson Hard-Soft theary I know that hard-hard interactions are ionic while soft-soft covalent
Here Li is much more hard than Cs so LiF is hard-hard and should be more ionic than CsF( Cs is soft)....and so less covalent than CsF
Is it a contraddition?