London dispersion forces are the intermolecular forces that occur between atoms, and between nonpolar. They are often called London dispersion forces after Fritz London (1900-1954), who first proposed their existence in 1930.
The gray arrows pointing away from each other represent repulsionīecause each end of a dipole possesses only a fraction of the charge of an electron, dipole–dipole interactions are substantially weaker than the interactions between two ions, each of which has a charge of at least ☑, or between a dipole and an ion, in which one of the species has at least a full positive or negative charge. Dispersion forces are also considered a type of van der Waals force and are the weakest of all intermolecular forces.
(CC BY-SA-NC anonymous) The green arrows pointing towards each other represent attraction.
\): Both attractive and repulsive dipole–dipole interactions occur in a liquid sample with many molecules.
