What happens to the energy of particles when a solid melts into a liquid (Changes of state)

The correct answer is Energy increases and particles move further apart..

Method lens: First identify the measured quantity, then match the equation or particle idea to the command word. This question asks: What happens to the energy of particles when a solid melts into a liquid (Changes of state). The correct response is Energy increases and particles move further apart., because gas pressure comes from particle collisions with container walls. In Changes of state, the marking point should connect directly to use the particle model to explain why gases are less dense than solids or liquids. 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 200 is distinct because it uses this exact question context and the method lens rather than a generic particle-model sentence.