---
title: "Solids, Liquids & Gases"
description: "Compare and group materials as solids, liquids, or gases based on their observable properties and behaviour"
canonical: https://lightmysky.com/learn/science/solids-liquids-and-gases-mt_YQkUdIHO8L
source: https://lightmysky.com/learn/science/solids-liquids-and-gases-mt_YQkUdIHO8L.md
retrieved: 2026-10-19
---

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# Solids, Liquids & Gases

Compare and group materials as solids, liquids, or gases based on their observable properties and behaviour

Subject: Science · Area: Matter & Materials · Ages 8 to 9
Page: https://lightmysky.com/learn/science/solids-liquids-and-gases-mt_YQkUdIHO8L

## Ready when they can

- Define solids (fixed shape, hard to compress), liquids (flow, take shape of container), gases (spread out, fill space)
- Sort at least eight everyday materials into solid, liquid, or gas categories
- Explain tricky cases like sand (solid particles) or steam (gas, not visible water droplets)

## Lesson: Solids, liquids, and gases: sorting by how they act

You already know solids, liquids, and gases by name. Today you compare how each one behaves and practice sorting real things into the right group, even some tricky ones.

*(drawing: Ice, water, and steam are the same substance. Only how it behaves changes: fixed shape, flowing shape, or spreading to fill space.)*

**Example.** Mia sorts things on the table. A rock keeps its shape and feels hard, so it is a solid. Orange juice flows to fit its glass, so it is a liquid. Air from a fan spreads out unseen, so it is a gas. She groups by behavior, not looks.

Three tricky cases. Sand pours, but each grain keeps its shape, so sand is a solid made of many pieces. Steam is a gas you cannot see. The white cloud above the kettle is tiny liquid droplets, not the gas. Toothpaste sits between the rules: it keeps its squeezed shape but flows under pressure, so it sorts closest to liquids.

**Recap.** Solids keep their shape, liquids flow to fit their container, and gases spread out to fully fill it, so sort by how each one behaves, not just how it looks.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [States of Matter Vocabulary](https://lightmysky.com/learn/science/states-of-matter-vocabulary-mt_1JFUNQDwAJ)
- [Grouping Materials](https://lightmysky.com/learn/science/grouping-materials-mt_SwaNNdm_Ks)
- [Changing Shapes of Solids](https://lightmysky.com/learn/science/changing-shapes-of-solids-mt_wf-SJhZ1kC)

## Opens up

- [Separating Mixtures](https://lightmysky.com/learn/science/separating-mixtures-mt_2b6CB0w3Yx)
- [The Particle Model](https://lightmysky.com/learn/science/the-particle-model-mt_b6kZgqolEd)
- [Advanced Material Properties](https://lightmysky.com/learn/science/advanced-material-properties-mt_Ge4Wtg6QMM)
- [Heating & Cooling Changes](https://lightmysky.com/learn/science/heating-and-cooling-changes-mt_Pl-nsjYGZ3)
- [Matter Is Made of Particles](https://lightmysky.com/learn/science/matter-is-made-of-particles-mt_ylruY6VhOf)