How can eletronegativity be used to distinguish between an ionic bond and a covalent bond?

Answer 1

If electronegativity varies by more than 1.4 then you are most probably looking at an ionic bond. A variance less than 1.4 means, usually a covalent bond can be formed.

This is a rule of thumb and is not always reliable. Metal to nonmetal; ionic. nonmetal to nonmetal; covalent.

Answer 2

Electronegativity can help distinguish between ionic and covalent bonds based on the difference in electronegativity values of the atoms involved. In an ionic bond, the electronegativity difference between atoms is typically large, leading to one atom fully transferring its electrons to another. In contrast, covalent bonds have a smaller electronegativity difference, resulting in atoms sharing electrons.