# Graphite and diamond are both giant covalent structures made entirely of carbon atoms, yet they have very different physical properties. Explain why graphite can conduct electricity but diamond cannot.

> OCR GCSE Chemistry A: Gateway Science (J248) — C2.2 Bonding · Explain · 4 marks

> Graphite is used as an electrode material in batteries and electrolysis cells, whilst diamond is used as an electrical insulator in cutting tools and heat sinks.

## Mark scheme (4 marks)

1. In graphite, each carbon atom forms three covalent bonds (with three other carbon atoms), leaving one electron per carbon atom not used in bonding.
2. In graphite, the remaining electron per carbon atom is delocalised (free to move) and can carry charge / carry an electric current.
3. In diamond, each carbon atom forms four covalent bonds with four other carbon atoms, so all electrons are used in bonding.
4. Because diamond has no delocalised (free) electrons, it cannot conduct electricity.

## Key terms

- [giant covalent structure](https://www.gradenine.co.uk/glossary/giant-covalent-structure)
- [graphite](https://www.gradenine.co.uk/glossary/graphite)
- [diamond](https://www.gradenine.co.uk/glossary/diamond)

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](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/graphite-and-diamond-are-both-giant-b507dda0) · Published by Druglandscape Ltd.