What Is a Gas?

• Gases are composed of particles that are moving randomly around and very fast in their container(s).

• Gas particles move in straight lines until they collide with either the container wall or another particle, then they bounce off.

• A gaseous atom or molecule exerts a force when it collides with a surface or other gaseous particles.

• Molecular collision is pressure.

• Gas pressure is a result of the constant movement of the gas molecules and their collisions with the surfaces around them.

• Pressure is the force exerted per unit area by gas molecules as they strike the surfaces around them.