In physics, chemistry, and biology, intermolecular forces are forces that act between stable molecules or between functional groups of macromolecules. Intermolecular forces (the weakest of which are van der Waals forces- also known as the London Dispersion Forces) include momentary attractions between molecules, diatomic free elements, and individual atoms. They differ from covalent and ionic bonding in that they aren't stable, but are caused by momentary polarization of particles. Because elec… (More on Intermolecular)