Intermolecular force is defined as the attraction and repulsion between the atoms or molecules of the substance is known as intermolecular force.
The strongest intermolecular force is seen in dipole-dipole interaction and it occurs only in the polar molecules.
The descending order of intermolecular force is .
The strongest type of dipole-dipole interaction is Hydrogen bonding.
Dipole-dipole interaction exists between the two permanent dipoles which interact between the partially positive charge ion of a molecular and the partially negative charge ion of another molecule.
For example, H-bonding between two water molecules.