The scattering is presented by the relations time or the mean free path.

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

I have persuaded my friend, the police commissioner, to give me a free path to that objective.

The new mean free path is then should be used:

They shifted constantly to keep a free path between prisoners and weapons.

In copper, for example, the mean free path is 40 nm.

In air the mean free path of molecules is about 96 nm.

At atmospheric pressure, the mean free path of air is about 70 nm.

He specified that the door must be open, with a free path here.

Electrons in air have a mean free path of 1cm.