According to the 1. theory, the particles of a gas are constantly moving. every time gas particles hit something and bounce off, they exert a tiny force. pressure is this amount of 2. exerted per unit of area. the amount of force exerted by a gas depends on the size of its container. 3. law states that if a sample of gas is kept at constant 4. , decreasing the volume will 5. the pressure the gas exerts. if you increase the volume, the pressure will 6. according to the kinetic theory, if you do not change the amount of gas or its temperature but 7. the size of the container, the particles will strike the walls more often and the pressure will rise. when the size of the container is 8. the pressure is smaller because the particles hit the walls less often.