What is London force ? Give its characteristics ?

Explanation

London force : Attraction forces present between symmetric atoms or molecules are knows as London forces or dispersion forces.
This force of attraction was first proposed by the German physicist Fritz London, and for this reasson force of attraction between two temporary dipoles is known as London force.
Characteristics :
Another name for this force is dispersion force.
It is present between symmetric atom or molecules.
e.g., `H_(2),Cl_(2),P_(4),CH_(4),C Cl_(4), C_(6)H_(6)`
There is always attraction forces.
These forces are always asttractive and interaction energy is inversely proportional to the sixth power of the distance between two interacting particles. (`1//r^(6)` where r is the distance between two particles)
These forces are important only at short distances (~ 500 pm) and their magnitude depends on the polarisability of the particle.