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

The correct answer is The pressure increases.

Practical lens: Link apparatus, readings, and uncertainty to the exact measurement named in the objective. This question asks: What happens to the pressure of a gas when its volume decreases at constant temperature (Pressure in gases (physics only)). The correct response is The pressure increases, 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) Apply MS 3b, MS 3c and MS 4a skills when calculating or interpreting pressure-volume relationships. 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 578 is distinct because it uses this exact question context and the practical lens rather than a generic particle-model sentence.