States of matter and the water cycle

For grown-ups: this lesson in words

Years 4 to 6 · Science

States of matter and the water cycle: I can sort solids, liquids and gases, and follow water round the water cycle.

1. Materials can be solids, liquids or gases. These are three states of matter.

   An ice cube is a solid. It keeps its own shape.

   Milk is a liquid. It flows and takes the shape of its glass.

   The air in a balloon is a gas. It spreads out to fill the whole balloon.

   Picture: Sorting into 3 groups: Solid, Liquid, Gas. Solid: Ice cube. Liquid: Milk (glass of milk). Gas: Air in a balloon (balloon).

2. Your turn: Which one is a liquid?

   Choose one:

   • Rock: rock
   • Water: raindrop
   • Air in a football: ball

   Answer

   The answer: Water

   Water is a liquid. It flows and takes the shape of its container.

3. Some materials are trickier to sort.

   Rice can be poured, but each grain keeps its own shape. So rice is a solid.

   Runny honey flows slowly, but it takes the shape of its pot. It is a liquid.

   The air in a bike tyre is a gas. It spreads out to fill the tyre.

   Picture: Sorting into 3 groups: Solid, Liquid, Gas. Solid: Rice (bowl of rice). Liquid: Runny honey (pot of honey). Gas: Air in a bike tyre (bike).

Words to know

solid:

A material that keeps its own shape.

liquid:

A material that flows and takes the shape of its container.

gas:

A material that spreads out to fill all the space it is in.

evaporation:

When a liquid warms up and turns into a gas.

condensation:

When a gas cools down and turns back into a liquid.

precipitation:

Water falling from clouds, as rain, snow or hail.