# Explain why buckminsterfullerene (C₆₀) has a significantly lower melting point than diamond, despite both being allotropes of carbon.

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

## Mark scheme (4 marks)

1. Diamond has a giant covalent (network) structure in which every carbon atom is covalently bonded to four others throughout the lattice.
2. Melting diamond requires breaking many strong covalent C–C bonds throughout the entire lattice, which requires a very large amount of energy.
3. Buckminsterfullerene consists of discrete, individual C₆₀ molecules held together in the solid state by weak London (dispersion) forces.
4. Only these weak intermolecular forces need to be overcome to melt C₆₀, so relatively little energy is required, giving a much lower melting point.

## Key terms

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

## Related

- [Revision notes for IB DP Chemistry Higher 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-buckminsterfullerene-c-has-a-0ddf6cdb) · Published by Druglandscape Ltd.