During a phase change, why does the temperature remain constant?

The correct answer is Energy is used to change the potential energy of the particles..

Definition lens: Give the precise definition, then add a context sentence that shows how it is used. This question asks: During a phase change, why does the temperature remain constant. The correct response is Energy is used to change the potential energy of the particles., because specific latent heat concerns energy transferred during a state change with no temperature rise. In Changes of state and specific latent heat, the marking point should connect directly to distinguish specific latent heat of fusion from specific latent heat of vaporisation. 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 Internal energy and energy transfers, 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 378 is distinct because it uses this exact question context and the definition lens rather than a generic particle-model sentence.