What happens to the density of a substance when it is heated ? P43-019 Density of materials checkpoint

The correct answer is Density decreases ? P43-019 density measurement and calculation.

Application lens: Apply the rule to the specific sample or situation instead of reciting a broad fact. This question asks: What happens to the density of a substance when it is heated ?. The correct response is Density decreases ? P43-019 density measurement and calculation, because density links mass and volume, so the answer must preserve which quantity is being calculated. In Density of materials, the marking point should connect directly to define density as mass per unit volume. 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 Changes of state and the particle model, 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 7 is distinct because it uses this exact question context and the application lens rather than a generic particle-model sentence.