I really hope that this helps. H-F because the difference in electronegativity is the greatest, about 1.9 on the Pauling scale. The term means which bond has the greatest polarity and is thus most similar to an ionic bond, which involves the transfer of an electron (in opposition to covalent bonds, which share electrons). It is H-F because out of all the atoms here bonded with H, ie hydrogen, F is the most electronegative which means it can pull the bonded electrons to itself more than can Cl, O, and N. <span>That means a stronger polarization of the electron cloud forming the bond with hydrogen and therefore a stronger ionic character.</span>
