# Explain why sublimation is described as a physical change rather than a chemical change.

> AQA GCSE Physics (8463) — 4.3.1 Changes of state and the particle model · Explain · 4 marks

> Dry ice (solid carbon dioxide) sublimates at room temperature, changing directly from a solid to a vapour.

## Mark scheme (4 marks)

1. Sublimation is a change of state (from solid directly to vapour/gas, without passing through the liquid phase)
2. Changes of state are physical changes because the substance retains its original properties / the change is reversible
3. In a chemical change the chemical structure of the substance changes / a new substance is formed
4. During sublimation only the arrangement / spacing of the particles changes, not the chemical structure / the substance remains carbon dioxide throughout

## Key terms

- [sublimation](https://www.gradenine.co.uk/glossary/sublimation)
- [physical change](https://www.gradenine.co.uk/glossary/physical-change)
- [chemical change](https://www.gradenine.co.uk/glossary/chemical-change)

## Related

- [Revision notes for AQA GCSE Physics (8463)](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-sublimation-is-described-as-8991a532) · Published by Druglandscape Ltd.