Why do gas particles collide with each other and with the walls of their container (Particle motion in gases)

The correct answer is Because they are in constant random motion..

Cause lens: Name the cause, then state the effect on particles, pressure, density, or energy. This question asks: Why do gas particles collide with each other and with the walls of their container (Particle motion in gases). The correct response is Because they are in constant random motion., because gas pressure comes from particle collisions with container walls. In Particle motion in gases, the marking point should connect directly to explain that faster gas particles collide more often and with greater force. 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 484 is distinct because it uses this exact question context and the cause lens rather than a generic particle-model sentence.