Particle motion in gases

The idea

The molecules of a gas are in constant random motion. The temperature of a gas is related to the average kinetic energy of its molecules. Gas pressure is caused by molecules colliding with the walls of the container. If a gas is heated in a sealed container of fixed volume, the molecules move faster, collide with the walls more often and harder, so the pressure increases.

1. Describe the motion of the molecules.
2. Link temperature to kinetic energy.
3. Link collisions to pressure.

Watch out Heating a gas does not make the molecules bigger: they move faster.