# Explain why graphite can conduct electricity whereas diamond cannot, despite both being allotropes of carbon.

> IB DP Chemistry Standard Level (2023 syllabus) — S2.4 From models to materials · Explain · 4 marks

## Mark scheme (4 marks)

1. In graphite, each carbon atom forms three covalent bonds, leaving one electron per carbon atom not involved in sigma bonding / forming a delocalised electron system.
2. These delocalised electrons are free to move through the layers and carry charge, so graphite conducts electricity.
3. In diamond, each carbon forms four covalent bonds in a tetrahedral arrangement, using all four valence electrons.
4. Because all electrons in diamond are localised in bonds, there are no mobile charge carriers, so diamond cannot conduct electricity.

## Key terms

- [allotrope](https://www.gradenine.co.uk/glossary/allotrope)

## Related

- [Revision notes for IB DP Chemistry Standard Level (2023 syllabus)](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-graphite-can-conduct-electricity-f5627271) · Published by Druglandscape Ltd.