Physics · KS3 and GCSE · Interactive lesson
Heating, particles and melting
Compare particle motion as a material warms. Explore why melting is different, then build towards specific heat capacity and latent heat calculations.
Choose your view
Explore an interactive example, then try the questions at your own pace.
KS3 / GCSE · start with the idea
By the end of this lesson: Explain how adding energy can warm a material.
The interactive diagram and controls are in Stage 2, “Explore one example”. Read the idea here, then try it next.
- In a solid, particles vibrate around fixed positions. In a liquid, they move past one another.
- When a material warms, its particles gain kinetic energy (energy of movement) on average.
- During melting, added energy changes the particle arrangement. The temperature stays at the melting point.
Useful starting points
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What do the words mean?
- Temperature
- Related to the particles’ average kinetic energy. It does not tell you the object’s total energy.
- Kinetic energy
- Energy something has because it is moving. Vibrating particles have kinetic energy too.
- Specific heat capacity (c)
- Energy needed to warm 1 kg of a material by 1 °C.
- Specific latent heat (L)
- Energy needed to change the state of 1 kg, without changing its temperature.
- ΔT (temperature change)
- Final temperature minus starting temperature. The Δ symbol means “change in”.
- E and m
- E means energy in joules (J). m means mass in kilograms (kg).
Change the example
This is the lesson example. Your practice question uses its own numbers.
Something to try
Press Play particle motion. Add energy in small steps. Compare the temperature and particle motion before and after.
Notice what changes
How particle motion works +
Starts paused. Press Play, then add energy to see the warmer particles move faster.
Particles keep the same size. Liquid particles move around; solid particles vibrate around fixed positions. This is a simplified model, with the change in motion exaggerated to make it easier to see.
About the playback +
About this model
Compare Start with Now. Press Play particle motion, then add energy. Liquid particles move past one another and stay close together. Warmer particles have more average kinetic energy; they do not grow. The animation exaggerates the change so it is easier to see. Its speeds and spacing are not measurements. The dots represent a few particles, not the sample’s mass. Model: 1 kg, with specific heat capacity c = 4200 J/(kg °C). No energy escapes and no change of state occurs. The full bar represents a 20 °C rise.
More about this diagram
Still picture. Play particle motion in Stage 2.
Temperature rise = 0 °C
Still picture of the example from Stage 2. Use the back arrow to change it.
Work through it
Starting example: read the steps below
- 0 J is transferred to 1 kg.
- Each kilogram needs 4200 J of energy to warm by 1 °C.
- More added energy means a larger temperature rise.
- Final temperature = 10 + temperature rise = 10 °C.
Try on your own
Your turn. No rush.
Question 1
Add energy to liquid water. It stays liquid and no energy escapes. What happens to its temperature?
About these questions
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These questions use their own numbers, separate from the lesson example. You can stop whenever you like. Answers last for this visit to the page.
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What is different about the temperature when a material warms and when it melts?
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Notes for parents and tutors
These lessons cover selected KS3 and GCSE ideas for England; they are not a complete course. The level notes explain where GCSE methods or optional extensions begin. Maurice can help you choose material for your course and exam board.
The content draws on the DfE Maths curriculum, DfE Science curriculum and AQA GCSE Physics specification. Level labels are guidance, not exam-board endorsements. For AQA Radioactivity, calculating net decline as a ratio is Higher-tier work. Net means the overall change; ask Maurice whether this extension is relevant to your course. Explanations and practice were reviewed during development on 21 October 2026; Maurice should check their fit before assigning work.
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