# Explain why a solid has a higher density than the same substance in the gaseous state, in terms of particles and their arrangement.

> IB DP Chemistry Standard Level (2023 syllabus) — S1.1 Introduction to the particulate nature of matter · Explain · 4 marks

## Mark scheme (4 marks)

1. In a solid, particles are closely/tightly packed together (with negligible space between them).
2. In a gas, particles are very far apart / widely spaced with large distances/spaces between them.
3. The same mass/number of particles therefore occupies a much larger volume in the gaseous state than in the solid state.
4. Density is mass per unit volume, so a greater volume for the same mass gives a lower density in the gas.

## Key terms

- [density](https://www.gradenine.co.uk/glossary/density)
- [solid](https://www.gradenine.co.uk/glossary/solid)
- [gas](https://www.gradenine.co.uk/glossary/gas)

## 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-a-solid-has-a-e2ada74d) · Published by Druglandscape Ltd.