How do Van der Waals forces arise between molecules?

1 Answer
May 21, 2018

Electron dipoles


At any point, electrons are moving 'randomly' in orbitals around atoms, so at any one point, more electrons may be on one side of the atom than the other, forming a small, instantaneous electron dipole where one side of the atom is negative and the other side is more positive.
This forms a temporary bond with other atoms which also have small, instantaneous electron dipoles.

Thus, the more electrons a molecule has, the stronger the Van der Waals forces can be said to be, as there is a greater probability of these small dipoles forming, and they will likely be more polar with more electrons being present.