# Explain why the temperature of a substance does not change while it is melting, even though it is being heated.

> AQA A-Level Physics (7408) — 3.6.2 Thermal Physics · Explain · 5 marks

> A student heats a block of ice and notices that the temperature stays at 0 °C for a period of time, even though the heater is switched on.

## Mark scheme (5 marks)

1. Energy is supplied to the substance during melting
2. The energy is used to break the bonds / intermolecular forces between the particles
3. The energy does not increase the kinetic energy of the particles
4. Temperature is related to the average kinetic energy of the particles, so temperature does not rise
5. The energy is stored as potential energy (of the particles) / increases the internal energy of the substance without raising temperature

## Key terms

- [melting](https://www.gradenine.co.uk/glossary/melting)
- [temperature](https://www.gradenine.co.uk/glossary/temperature)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-the-temperature-of-a-56002a6a) · Published by Druglandscape Ltd.