When there is an electronegativity difference between two covalently bonded atoms, what is true of the bond between them?

The bond will generate a dipole

Explanation:

When there is difference of electronegativity between two atoms in a covalent union it means that they both have different affinities to the electrons.

The pair of electrons in the bond will be more attracted to the atom with the higher electronegativity.

This causes that this atom ends up with a negative charge due to the electrons it attracts. On the other side, the less electronegative atom will end up with a positive charge.