# Explain why thermal energy transfer by convection cannot occur in a solid.

> IB DP Physics Standard Level (2023 syllabus) — B.1 Thermal energy transfers · Explain · 4 marks

> Convection is one of three mechanisms by which thermal energy can be transferred. It is commonly observed in fluids such as liquids and gases but not in solids.

## Mark scheme (4 marks)

1. Convection requires the bulk movement (flow) of matter/particles to transfer thermal energy.
2. In a solid, particles are held in fixed positions by strong intermolecular/interatomic forces and cannot move freely from place to place.
3. Because particles cannot move freely, hotter (more energetic) regions cannot carry energy to cooler regions by bulk flow.
4. Convection currents depend on density differences causing fluid to rise and fall; solids do not exhibit these density-driven flows.

## Key terms

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

## Related

- [Revision notes for IB DP Physics Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-thermal-energy-transfer-by-d6b0e30d) · Published by Druglandscape Ltd.