Explain why the temperature of a substance remains constant during a change of state, even though energy is being transferred.

During a change of state, the energy transferred is used to alter the potential energy of the particles rather than their kinetic energy. As a result, while energy is being absorbed or released, the temperature remains constant until the entire substance has changed state.

Definition lens: Give the precise definition, then add a context sentence that shows how it is used. This question asks: Explain why the temperature of a substance remains constant during a change of state, even though energy is being transferred. The correct response is During a change of state, the energy transferred is used to alter the potential energy of the particles rather than their kinetic energy. As a result, while energy is being absorbed or released, the temperature remains constant until the entire substance has changed state., 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 define specific latent heat as the energy needed to change the state of one kilogram of a substance with no change in temperature. 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 366 is distinct because it uses this exact question context and the definition lens rather than a generic particle-model sentence.