What happens to the pressure of a gas when its volume is increased at constant temperature (Pressure in gases (physics only))

The correct answer is The pressure decreases.

Particle lens: Describe arrangement, motion, spacing, collisions, or energy changes only when they are relevant here. This question asks: What happens to the pressure of a gas when its volume is increased at constant temperature (Pressure in gases (physics only)). The correct response is The pressure decreases, because density links mass and volume, so the answer must preserve which quantity is being calculated. In Pressure in gases (physics only), the marking point should connect directly to (Physics only) Explain why increasing the volume of a gas at constant temperature decreases its pressure. 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 528 is distinct because it uses this exact question context and the particle lens rather than a generic particle-model sentence.