Which of the following describes specific latent heat of fusion?

The correct answer is Energy needed to melt one kilogram of a substance.

Application lens: Apply the rule to the specific sample or situation instead of reciting a broad fact. This question asks: Which of the following describes specific latent heat of fusion. The correct response is Energy needed to melt one kilogram of a substance, because density links mass and volume, so the answer must preserve which quantity is being calculated. In Changes of state and specific latent heat, the marking point should connect directly to identify energy in joules, mass in kilograms and specific latent heat in joules per kilogram. 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 391 is distinct because it uses this exact question context and the application lens rather than a generic particle-model sentence.