Electronic theory of valency and bonding

When covalent bond forms then the bonding pair of electron does not lie exactly midway between the reacting atoms but the pair of electron lies ear toward the atom which have more electronegativity. Since, the electrons shift towards it the atom having more electronegativity bears partial negative charge and the atom having less electronegativity possess partial positive charge. Such molecules are called polar molecules & the bond is called polar covalent bond the product of he magnitude of charge developed ina an atom of a polarized molecule & the distance between the combing atom is called dipole moment Learn More