This definitions covers Key Definitions within Specific Latent Heat for GCSE Physics. Revise Specific Latent Heat in Particle Model for GCSE Physics with 13 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 6 of 12 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
📖 Key Definitions
Specific latent heat (L): The energy required to change the state of 1 kg of a substance without changing its temperature. Units: J/kg.
Specific latent heat of fusion (Lf): Energy per kg needed to melt a solid (or freeze a liquid). For water: 334,000 J/kg.
Specific latent heat of vaporisation (Lv): Energy per kg needed to boil a liquid (or condense a gas). For water: 2,260,000 J/kg.
Latent: From Latin meaning "hidden" — it is "hidden" because it changes the state of the substance without changing its temperature, so a thermometer cannot detect it.
Specific heat capacity (c): Energy per kg per degree to change temperature WITHIN a state (contrasted with latent heat which is for state changes at constant temperature).
Practice questions for Specific Latent Heat
What is specific latent heat?
During a state change, energy is being supplied to a substance but the temperature does not change. Explain where this energy goes.