There are several models possible, to interactions between molecules or planets.

In a gas the mean free path may be much larger than the average distance between molecules.

A variety of weak forces act between liquid molecules to cause this effect.

As a gas expands, the average distance between molecules grows.

A lone pair can be used to form new bonds between molecules.

The interactions between atoms or molecules are described as "potential".

The peculiar structure reduces the strength of the forces between molecules.

This results in a relatively strong Coulomb force between molecules.

The stronger the bonds between molecules, the higher the melting point will be.

The network structure has a lot of space between molecules.