VANDER WAALS BOND:
A fourth type of bonding, which does not involve a transfer or sharing of electrons, is known as the Vander walls bond. It forms in atoms or molecules that become dipoles temporarily or permanently. In a dipole, the centre of positive charge and the centre of negative charge are not the same. The asymmetric charge distribution in dipoles can draw them to each other by columbic attraction, bonding them together. It is the weakest among atomic bonds.