Explain the difference between specific latent heat of fusion and specific latent heat of vaporisation.

Specific latent heat of fusion is the energy required to change a substance from solid to liquid at its melting point without changing its temperature. In contrast, specific latent heat of vaporisation is the energy needed to change a substance from liquid to gas at its boiling point, also without a temperature change.

Graph lens: Read the trend, flat section, gradient, or axis labels before explaining the physical meaning. This question asks: Explain the difference between specific latent heat of fusion and specific latent heat of vaporisation. The correct response is Specific latent heat of fusion is the energy required to change a substance from solid to liquid at its melting point without changing its temperature. In contrast, specific latent heat of vaporisation is the energy needed to change a substance from liquid to gas at its boiling point, also without a temperature change., because the particle model explains the observable property using particles. In Changes of state and specific latent heat, the marking point should connect directly to apply MS 4a and MS 4c skills when interpreting graphs of temperature against time. 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 435 is distinct because it uses this exact question context and the graph lens rather than a generic particle-model sentence.