# Graphite and diamond are both giant covalent structures made entirely of carbon atoms, yet they have very different properties. Describe the structure of graphite and explain why graphite can conduct electricity whilst diamond cannot.

> Pearson Edexcel International GCSE Chemistry (4CH1) — 1.7 Covalent substances · Describe and Explain · 4 marks

## Mark scheme (4 marks)

1. Each carbon atom in graphite forms three covalent bonds with three other carbon atoms, forming layers of hexagonal rings
2. There are no covalent bonds between the layers
3. Each carbon atom in graphite has one delocalised electron per carbon atom that is free to move
4. In diamond, all four outer electrons are used in covalent bonds so there are no delocalised/free electrons to carry charge

## 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 Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and 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-751015c5) · Published by Druglandscape Ltd.