Daddy Day Science #2: Heated Air Expands

Thursday – Daddy Day – Science Day! In the second experiment I wanted to show my daughter that air expands when it gets warmer. My favourite “science” book offered a good 5 minute experiment. Take a bottle, put a balloon over the top, put the bottle into a pot with cold water and warm up the water on the stove. Honestly I didn’t expect such a quick and clear reaction! And my daughter loved it!

Heated Air Expands

The experiment setup: pot with cold water, empty glass bottle and a balloon

Adding the balloon to the bottle

Heating the water on the stove

Hurray! The hypothesis has been confirmed! The air that gets heated by the warming water expands and inflates the balloon


Cooled Air Contracts

Now testing the reverse effect. Does the balloon deflate when the air gets cooled by cold water from the tap?

Indeed it does!

The video below shows a time lapse of the first phase:


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