S2.4.1 For the adult

Solids, liquids and gases

Why does water change shape, but a stone does not?

What this chapter teaches

A solid keeps its shape. A liquid takes the shape of its container but keeps its amount. A gas spreads to fill any container. Sand and salt pour, but each grain is a solid.

Three questions to ask

There is no one right wording. Listen for the idea.

  1. Why is sand a solid even though it pours?
  2. What happens to the shape of water when you pour it from a cup into a bowl?
  3. How is a gas different from a liquid in a closed jar?

After the chapter, the learner can

  • Sort materials into solids, liquids and gases
  • Describe how each one keeps or changes its shape

What they copy into their notebook

A solid keeps its shape. A liquid takes the shape of its container, but the amount stays. A gas spreads to fill any container. Sand pours, but each grain is a solid.

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