Help your kids learn about and understand air pressure by helping them understand that air is real, expresses energy, and exerts pressure with these fun, hands on science projects for kids of all ages. This is a wonderful introduction to be able to understand how airplanes fly.

Air Pressure

Air is Real Science Experiment

Show kid that air is real. Show them an empty soda bottle and ask them what is inside - chances are they will say nothing. Now put a balloon over the top.

Set 2 liter bottle in boiling water and watch the balloon inflate. (as air is heated the molecules spread out)

If it were empty how could it inflate? Air is real - we just can't see it!

Air Expresses Energy

You will need an empty soda can which you put just a little water in. Now heat it on the stove until hot. Meanwhile get ready a large bowl of ice water.

Now using tongs quickly put the hot can in the very cold water. It should collapse.

As the water was brought to a boil, the can quickly filled with steam which pushed out all the air. When the steam is cooled off by the cold water, it condenses into a few drops of water, leaving a vacuum in its place. The air crushes the can as it tries to get inside.

Think of examples of air pressure in nature: wind, tornado, or even when your ears pop when the plane goes up.

Air Pressure and Straws

Pick two children to compete in this science project. They should both have a glass containing a beverage. Put a straw in each glass, but one of the straws should have holes in them. Have the children compete to see who can drink the liquid the quickest.

The child trying to drink out of the straw with holes in it will be unsuccessful. Give them a new straw to drink and then explain about air pressure and straws.

When you sip on a straw, you lower the air pressure inside the straw. As a result, the outside air pressure, which is greater, pushes down on the surface of the liquid, forcing it to move up the straw. When some of you sipped on the straw with the holes, however, the air pressure was pulled directly inside via the holes. The pressure did not exert itself on the water, so the water did not rise up your straw.

Egg in a Bottle Science Experiment

Explain that just like water contracts when frozen or expands when heated, air does as well. Demonstrate this by giving everyone a bottle with an opening that is too small for the hard boiled egg to fit through.

Have an adult light a fire on a rolled up piece of paper and quickly drop it in the bottle. When the flame has gone out quickly set the egg on top of the bottle - watch as the egg is sucked into the bottle.

When the fire goes out it cools off and shrinks, or contracts. As it contracts, it leaves a partial vacuum inside. The outside air that was pushed out earlier then pushes the egg into the bottle as it tries to get back inside.

Now reverse the experiment. Place the bottle in a bowl of very hot water. The air expands and needs somewhere to go so it will push the egg out to have more room.

Here you can see our Egg in a Bottle Science Experiment in reverse!

More Fun Science Activities for Kids

Beth Gorden

Beth Gorden is a homeschooling mother of six who strives to enjoy every moment with her kids through hands-on learning, crafts, new experiences, and lots of playing together. Beth is also the creator and author of 123 Homeschool 4 Me where she shares 1000+ free printables, creative homeschool lessons, crafts, and other fun ideas to help preschool and homeschooling families have fun while learning and exploring together.