The Three States of Water
The three states of water explained for ages 4-6: solid ice, liquid water and gas vapour. Learn how water freezes, melts and turns to steam, with a fun quiz.
Key takeaways
- Water can be a solid, a liquid or a gas
- Solid water is ice — it is hard and cold
- Liquid water flows and pours, like in a glass or a river
- Gas water is called water vapour or steam, and we cannot see it well
- Heating and cooling change water from one state to another
One thing, three forms
Here is something amazing. Water can change its shape and feel — but it is still water all along! Water can be a solid, a liquid or a gas. These are called the three states of water.
You see all three states in your own home. Let's meet them.
Solid: ice 🧊
When water gets very, very cold, it freezes. Frozen water is called ice. Ice is a solid. It is hard and cold. You can hold an ice cube in your hand. You can stack ice cubes in a pile.
Ice keeps its shape. An ice cube stays a cube until it melts. We see ice in the freezer, on a frosty morning, and as snow in winter.
Liquid: water 💧
When ice gets warm, it melts. It turns into the wet water we know. This is a liquid.
Liquid water flows. It pours from a jug. It splashes and drips. It takes the shape of whatever holds it — round in a cup, flat in a puddle. We drink liquid water, wash with it and swim in it. Rivers and the sea are full of liquid water.
Gas: water vapour ☁️
When water gets very hot, it can turn into a gas called water vapour. When a pot of water boils on the stove, you see cloudy steam rising. That is water becoming a gas and floating up into the air.
Water vapour is so light it floats. We cannot see clear water vapour very well — it hides in the air all around us. Warning: steam from a hot pot or kettle is very hot. Never touch it. Always watch with a grown-up.
Heat and cold do the magic
How does water change states? With heat and cold.
- Make water very cold → it freezes into ice (solid)
- Warm up ice → it melts into water (liquid)
- Make water very hot → it turns into vapour (gas)
- Cool down vapour → it turns back into water (liquid)
Water changes back and forth, again and again. This even happens in the sky! You can learn about that in The Water Cycle. Water changes with the cold and warm days too, like in The Four Seasons.
Try this — watch ice melt!
Ask a grown-up to give you one ice cube on a small plate. Put it somewhere warm, like a sunny windowsill. Watch it! What do you see? The hard, cold ice slowly turns into a little puddle of water. The warm air gave it heat, so the solid melted into a liquid. How long did it take? Try one cube in a cold spot and one in a warm spot. Which melts first?
Solid, liquid, gas — and it is all just water!
Quick quiz
Test yourself and earn XP
What do we call water when it is frozen and hard?
Frozen, hard water is called ice. It is a solid.
What happens to ice when it gets warm?
Warm ice melts and becomes liquid water you can pour.
What do we call the cloudy gas that rises from a hot pot of water?
Hot water makes steam, which is water as a gas rising into the air.
How do we turn liquid water into solid ice?
We make water very cold, like in a freezer, and it freezes into ice.
Which one can you pour into a cup?
Liquid water flows and pours. Ice is solid and hard, so it cannot pour.
FAQ
Almost! Real steam is a clear gas you cannot see. The white cloud you see just above a kettle is tiny drops of water that have cooled a little in the air. So that cloud is water turning back into a liquid. Real steam is invisible and very hot, so we never touch it.
When water freezes into ice, it spreads out a little and becomes lighter than the water around it. That is why ice cubes float on top of your drink and why ice floats on a cold pond. It is a special trick that water does that most things cannot.
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