Compare Solids, Liquids, and Gases

Compare Solids, Liquids, and Gases

What students learn

Students learn that solids, liquids, and gases have different properties. Begin with Solids: Explain Why Solids Keep Their Shape and ask what stays the same when a solid is moved.

Why it matters

Comparing states of matter helps students explain why a rock keeps its shape, water pours, and air spreads out. Use States of Matter Song: Solid Keeps Its Shape for a quick check before moving to liquids.

Learn the idea

A solid keeps its own shape and volume. A liquid keeps its volume but takes the shape of its container. A gas spreads out to fill space. Watch Liquids: Explain Why Liquids Flow and Pour and then Gases: Explain Why Gases Spread Out to compare how each state behaves.

Try it

Show a block, a cup of water, and an inflated balloon. Ask students to describe shape and volume for each. Then use Particle Model: Compare Motion in Solids, Liquids, and Gases before they draw particles for all three states.

Parent guide

At home, compare an ice cube, water in a cup, and air in a bag. Ask your child what changes shape and what keeps shape. If they say gas is nothing, squeeze the bag gently and ask what is inside taking up space.