States of Matter: Gases

Contributor: Samantha Penna. Lesson ID: 11757

What shape is air? Can you grab it and hold it? What happens to bubbles when they pop? Where does the air go? Learn about gases and how they act with a hands-on scientific experiment!


Physical Science

learning style
Kinesthetic, Visual
personality style
Grade Level
Primary (K-2)
Lesson Type
Quick Query

Lesson Plan - Get It!

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  • Is a balloon a solid, liquid, or gas?

This may take some thought, so read on!

Everything on the earth is made up of matter. Solids, liquids, and gases are made up of matter.

The balloons you saw at the beginning of the lesson are filled with gas. They may be filled with helium or air. Both of these are gases.

  • Can you see how the balloons come in many shapes and sizes?

The gases fill the space inside the different shapes of balloons. Balloons are solid, but they are filled with gas!

All gases are made up of atoms. Atoms and molecules (groups of atoms) make up everything on the earth.

The atoms and molecules in gases move around a lot and are spread far apart. The atoms and molecules in a gas are always moving around. They are similar to liquids in a way. They take the shape of any container they may be in.

For example, if you fill a balloon with helium or air, the gas will take up the shape of the balloon. This is similar to how liquids take the shape of the container they are poured into.

states of matter

Watch the video below to see how the molecules in gases move around.

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You saw how gases move around. If you were to fill up a basketball with air and then let all the air out of the ball, the air would take the shape of the room you were in.

deflated basketball

You breathe in oxygen. Oxygen is a gas. Other gases around you are nitrogen, argon, and carbon dioxide.

Some gases can be dangerous to humans. For example, carbon monoxide is a poisonous gas.


Gases can be very different from each other. For example, you can see steam from boiling water, but you cannot see the oxygen you are breathing right now.

You can smell certain gases too. For example, when added to pool water, you can smell chlorine.

bad smell

You learned some facts about gases.

  • What would happen to a gas if you opened a container it was in?

After answering, move on to the Got It? section to explore gases by playing games.

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