Question

What causes dipoles?

Answer 1

The uneven sharing of electrons between two atoms of significantly different electronegativity values cause dipoles.

Explanation:

Basically, more electronegative atoms pull electrons closer to them in a covalent bond. The pulling of electrons to the electronegative atom induces a slight negative charge. On the other hand, the atom that is 'losing' the electrons in the shared bond may gain a slight positive charge from the loss of electrons. Since electrons have a negative charge, having more on one atom gives it a negative charge and taking them away from an atom gives that atom a positive charge. This induces dipoles.