How does electronegativity affect ionic bonding?

The more electronegative an atom is, the more its bonds to other atoms will have ionic character, especially to that have metallic character.

The most electronegative atom is fluorine, F. When a fluorine atom bonds to almost any other atom (except another F atom), the bond has ionic character because of partial transfer of an electron from the other atom to fluorine.

##HF## and ##NaF## have ionic bonds because elements in the first column of can transfer their single valence electron to another atom with relative ease.

##N-F## bonds, such as in ##NF_3## have partial ionic character and partial covalent character.

##F_2## has a completely covalent bond because both atoms are highly electronegative, but neither can win the battle for the electrons.