# Explain why a substance in the liquid state has a definite volume but no definite shape, in terms of the arrangement and motion of its particles.

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

## Mark scheme (4 marks)

1. Particles in a liquid are close together / touching, so the volume is fixed / cannot be easily compressed.
2. Intermolecular forces in a liquid are strong enough to keep particles close but not strong enough to hold them in fixed positions.
3. Particles in a liquid can move / flow / slide past one another.
4. Because particles can flow/move past each other, the liquid takes the shape of its container / has no definite shape.

## Key terms

- [definite volume](https://www.gradenine.co.uk/glossary/definite-volume)
- [no definite shape](https://www.gradenine.co.uk/glossary/no-definite-shape)

## 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-substance-in-the-fe442bea) · Published by Druglandscape Ltd.