# A candle is made of wax. When a candle burns, liquid wax forms near the flame and a new white solid forms as the candle cools further from the flame. At the same time, carbon dioxide and water vapour are produced near the flame. State which of these observations represents a physical change and which represents a chemical change, and justify each answer.

> Cambridge International IGCSE Chemistry (0620) — 6.1 Physical and chemical changes · Justify · 4 marks

## Mark scheme (4 marks)

1. The melting of wax (or solidification of wax) is a physical change
2. Justification: no new substance is formed / the change is reversible / wax can be recovered
3. The burning of wax (production of carbon dioxide and water vapour) is a chemical change
4. Justification: new substances are formed / the change is irreversible / carbon dioxide and water cannot easily be converted back to wax

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
- [How to answer "Justify" 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/a-candle-is-made-of-wax-ff60adfb) · Published by Druglandscape Ltd.