Atmospheric Pressure Experiment

Can you feel the pressure? The atmospheric pressure that is.

The air in our atmosphere is constantly pushing on us and everything else, for that matter.

There is even air pressure inside your body pressing outward. The air pressure inside your body counteracts the air pressure outside your body. This is how it is with most things in earth. Comparable air pressure keeps things stable.

What happens when you mess with this balance of air pressure? Test it with this atmospheric pressure experiment.

Soda Can Air Pressure Experiment

Supplies

• Stove
• Frying pan
• 2 empty, 12 oz aluminum cans
• 2 bowls
• Water
• Ice cubes
• Tongs
• Eye protection

Procedure

1. Put just enough water in each aluminum can to cover the bottom of the can.

2. Fill each bowl half full of water and add several ice cubes to cool the water. The water needs to be very cold.

3. Stand the cans in a frying pan right side up.

4. Place the frying pan on the stove and turn the heat on “high”.

5. Watch for steam to come out of the top of the can. This might take a couple minutes.

6. When a steady stream of steam comes out of the can, use the tongs to grab one can and place it upright in one bowl of ice water. Note what happens.

7. Use the tongs to grab the second can and place it upside down in the second bowl of ice water. Note what happens.

What Happened?

Before the experiment started, the air pressure inside the can and outside the can were the same. This stable air pressure allowed the can to keep it’s shape.

When the water inside the cans was heated, the steam pushed the air out of the can. This steam now exerted pressure on the inside of the cans, but it was the same as the air pressure pushing on the outside of the cans. This allowed the cans to keep their shape.

Placing the first can upright into the ice cold water changed the steam rapidly back to water. This caused air to rush back into the can keeping the air pressure in the can the same as the outside air pressure and allowing the can to keep its shape.

When the second can was placed upside down into the ice cold water, the steam was again rapidly changed into water. However, since the opening of the can was under the water, air could not rush into the can to replace the steam as in the first can.

Since there was little air pressure inside the can, there was not enough air pressure to counteract the air pressure outside the can. As a result the outside air pressure crushed the can.

Apologia Physical Science

This is one of the fun science experiments that you’ll do while studying Apologia’s Physical Science. This curriculum was designed to be an 8th grade curriculum to be used before Apologia Biology in high school.

My 13 year old (8th grade) is going through this curriculum independently, for the most part, and loving it. This is her 5th year with Apologia science. She is a big fan!

For more science fun from Apologia science…..

• Oxygen and fire experiment from Apologia Physical Science
• Take a peek at our journey through Apologia’s Anatomy and Physiology with our Science Saturday posts
• Check out these experiments in The Lab Report sponsored by Apologia Science
• Why Apologia Science Is Great For Homeschool Co-ops
• Why Use Apologia Notebooking Journals

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