# When a cold pack is applied to a sports injury, a chemical reaction occurs inside the pack and the pack feels cold. Explain why the pack feels cold, referring to energy transfer and bond breaking and bond forming.

> AQA GCSE Chemistry (8462) — 4.5.1 Exothermic and endothermic reactions · Explain · 4 marks

## Mark scheme (4 marks)

1. The reaction is endothermic
2. The reaction takes in energy from the surroundings
3. The temperature of the surroundings decreases
4. The energy needed to break bonds in the reactants is greater than the energy released when bonds in the products are formed

## Key terms

- [bond breaking](https://www.gradenine.co.uk/glossary/bond-breaking)
- [bond forming](https://www.gradenine.co.uk/glossary/bond-forming)

## Related

- [Revision notes for AQA GCSE Chemistry (8462)](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/when-a-cold-pack-is-applied-ce597695) · Published by Druglandscape Ltd.