Dipole Moment Significance

[Erik Buetow 1F]

First, what does a dipole moment actually indicate? Second, do all bonds have a dipole moment or only specific ones?

[Prasanna Padmanabham 4I]

Dipole moment exists for any covalently bonded molecules where the atoms have different electronegativities. This is because one atom will exert a stronger force on the electrons and "hog" the electrons from the less electronegative atom. Therefore, the dipole moment exists when there is a difference between electronegativities.

The closer the electronegativities are, the less of a dipole moment exists. For example, there would be no dipole movement between two Oxygen atoms in an O2 molecule, but a dipole moment exists for H2O because Oxygen is more electronegative than Hydrogen.