What happens to the energy of a gas when work is done on it?

The correct answer is The energy increases.

Definition lens: Give the precise definition, then add a context sentence that shows how it is used. This question asks: What happens to the energy of a gas when work is done on it. The correct response is The energy increases, 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) Explain that doing work on a gas transfers energy to the gas. 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 582 is distinct because it uses this exact question context and the definition lens rather than a generic particle-model sentence.