How do gas particles behave in a container?

The correct answer is They move in constant random motion..

Unit lens: Check the units before giving the final statement so the physics quantity is not swapped. This question asks: How do gas particles behave in a container. The correct response is They move 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 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 457 is distinct because it uses this exact question context and the unit lens rather than a generic particle-model sentence.