Polar bonds – When a covalent bond is formed between atoms with different electronegativity values, the more electronegative atom will have a greater attraction for the pair of electrons in the covalent bond. Polar bonds, as well as polar molecules, can have bonds that possess polarity. When a covalent bond molecules show some ionic character, we call these molecules as polar covalent molecules, like H2O.
The bond dipole is the unit of measure that chemists use to describe the amount of polarity in a polar bond. The dipole moment of a molecule is the measure of the polarity of an entire molecule.
The bond dipole of a molecule is the product of the charge (e) and the distance (d) between the nuclei of the bonded atoms
μ = e x d
The charge is the magnitude of either the positive or negative charge because in a neutral molecule the magnitude of both is equal.