How are gas molecules arranged inside a container?

Gases do not have a fixed structure; instead, they consist of a vast number of molecules that are distributed essentially randomly in space. These molecules are separated by distances that are large compared to their own size, allowing them to move chaotically in all directions.5123

Inside a container, gas molecules exhibit the following characteristics:

• Random Motion: Molecules travel in arbitrary directions at speeds that are distributed randomly about an average determined by the gas temperature.1
• Collisions: The molecules frequently collide with one another and with the walls of the container. These collisions are considered perfectly elastic, meaning there is no loss of energy during the impact.124
• Filling the Space: Because the particles are moving fast enough to escape each other's influence, gases will completely fill any closed container, regardless of its shape.54
• Pressure Generation: The pressure exerted by a gas is the result of the innumerable impacts of these molecules against the container walls.16