PROBLEM | What happens to marshmallows when you put them in a sealed jar and pump air on them? |
PROCEDURE | Get a large threaded test tube. Drop four mini-marshmallows inside. Screw on a hand pump really tight. Pump it 20 times while watching the marshmallows. What happens to them? Next try this same experiment using a vacuum pump. |
MATERIALS | four mini marshmallows test tube hand pump |
HYPOTHESIS | A. The marshmallows grow in size. (5) B. The marshmallows get smaller. (4) C. The marshmallows turn into one big blob. (4) D. The marshmallows turn into liquid. (3) |
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CONCLUSION | The marshmallows get smaller! Air takes up space and the more air you squish into the test tube the less room the marshmallows have. You've created a high air pressure environment. The extra air is pushing really hard on the marshmallows. Air is made up of 78% Nitrogen, 21% Oxygen, and 1% other gases? All that air takes up a lot of space! |
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Check out the opposite situation. With a vacuum pump the air is taken out and you create a low air pressure environment. The marshmallow now has room to expand, but the container is really hard to open...until you let the air back in.
