Why does gas pressure increase when the volume of a gas decreases at constant temperature (Particle motion in gases)

The correct answer is Particles collide more often with greater force..

Cause lens: Name the cause, then state the effect on particles, pressure, density, or energy. This question asks: Why does gas pressure increase when the volume of a gas decreases at constant temperature (Particle motion in gases). The correct response is Particles collide more often with greater force., because gas pressure comes from particle collisions with container walls. In Particle motion in gases, the marking point should connect directly to explain that gas particles collide with each other and with the walls of their container. If the question includes values, the working must keep the appropriate unit and operation; if it is an explanation, it must name the relevant particle behaviour or energy change. This item belongs to Particle model and pressure, so avoid answers that switch to a different quantity, confuse heat with temperature, or describe gas pressure without collisions when collisions are the reason. Checkpoint 460 is distinct because it uses this exact question context and the cause lens rather than a generic particle-model sentence.