Balloon battle

Friday, February 20, 2009

Is there more air pressure in a smaller balloon or a larger balloon? Grab a few items from around the house for the answer.


* 2 balloons

* Thread spool

* Twist ties


STEP 1: Completely blow up one of the balloons and tie it off with a twist tie.

STEP 2: Partially blow up the second balloon and tie it off with a twist tie.

STEP 3: Keeping the balloons tied with the twist ties, stretch the end of each balloon over the ends of the thread spool.

STEP 4: Remove the twist ties from the both balloons.


When you removed the twist ties, the air from the smaller balloon rushed into the larger balloon. The reason: The air molecules are closer together in the smaller balloon creating more pressure. When you removed the twist ties, the stronger pressure in the smaller balloon forced the air molecules into the larger balloon.

Jason Lindsey is a Science Outreach Educator with Hooked on Science. Check out his website "Hooked On Science" at for webcasts and experiments that might get you hooked on science. Send him your science questions at More science experiments can be found at

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