What is the specific latent heat of a substance?

The correct answer is The energy needed to change the state of one kilogram without changing temperature..

Method lens: First identify the measured quantity, then match the equation or particle idea to the command word. This question asks: What is the specific latent heat of a substance. The correct response is The energy needed to change the state of one kilogram without changing temperature., because changes of state are explained by particle energy and arrangement. In Changes of state and specific latent heat, the marking point should connect directly to explain why temperature remains constant during a change of state even though energy is transferred. 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 416 is distinct because it uses this exact question context and the method lens rather than a generic particle-model sentence.