What are Van Der Waals dispersion forces?
Van der Waals forces are a form of intermolecular (between molecules) force.
A covalent bond is created by a shared pair of electons. (For example two chlorine atoms will share 2 electrons to form a Cl2 molecule).
Within a covalent bonds, the electrons are not fixed, but constantly moving around the atoms. These may form temporary dipoles (even if the two atoms are of equal electronegativity such as Cl2).
These temporary dipoles will attract their opposite dipole and repel the same dipole (ie. d+ attracts d-). These random temporary dipioles are constantly forming, leading to attraction between molecules.
Van der Waals dispersion forces are considered a weak form of intermolecular force.
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