What is the relationship between pressure and volume for a fixed mass of gas at constant temperature (Increasing the pressure of a gas (physics only) (HT only))

The correct answer is Pressure is inversely proportional to volume.

Unit lens: Check the units before giving the final statement so the physics quantity is not swapped. This question asks: What is the relationship between pressure and volume for a fixed mass of gas at constant temperature (Increasing the pressure of a gas (physics only) (HT only)). The correct response is Pressure is inversely proportional to volume, because gas pressure comes from particle collisions with container walls. In Increasing the pressure of a gas (physics only) (HT only), the marking point should connect directly to (Physics only) (HT only) Use the particle model to explain energy transfer during gas compression. 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 625 is distinct because it uses this exact question context and the unit lens rather than a generic particle-model sentence.