Science Smarts: Mastering the science behind water balloons to maximize chances of victory!

By Patty Rooks on May 17, 2025.

I can hardly believe it is May already. I know the weather this week has made it feel like spring is finally arriving in southeastern Alberta. In order to appreciate the great weather, I think we should take some science outside this weekend so we can get messy and officially kick off the start of summer.

You will want to do this one, as it will help you out with those water balloon fights this summer – you will be the champion of the neighbourhood. Let’s get started!

*Remember to ask an adult before doing this experiment.

Materials

– Water balloons

– Somewhere to fill the balloons

– Outdoor location for science testing

– Science helper

Procedure

1. Have an adult help you fill a water balloon as full as possible with water. Tie it off, ensuring there is not any air in there.

2. Take another balloon and fill it only half full of water and tie it off.

3. It is testing time, take your balloons outside.

4. Once you are outside, hold the balloon that you filled as full as possible about shoulder height. Drop it.

5. Observe.

6. What happens?

7. Repeat with the other balloon.

8. Was there a difference?

9. Go outside and hold the balloon up at about shoulder height and drop it. It will most likely break.

10. Fill another balloon about halfway with water, then carefully fill the balloon the rest of the way with air. If you aren’t careful, you may get a face full of water doing this, so you may want to make sure you are outside. Once the balloon is blown up tie it off.

11. Hold the balloon up at shoulder height and drop it on the ground. This time the balloon shouldn’t have broke.

Explanation:

You may be asking yourself, why did the full balloon break and the half full one didn’t? It has to do with the air you left trapped in the balloon. This is because air is compressible, and water is not.

When you dropped the balloon with the air in it, the air compressed as it hit the ground and absorbed some of the shock and making the stress on the balloon less, and as a result, does not break.

The balloon that is full of water doesn’t have that air pocket to cushion the fall and absorb some of the shock so it breaks when you drop it.

If you want you can play with the amount of air and water that you have in the balloons to see how much air you have to have in the balloon to cushion the fall enough to stop the balloon from breaking. I highly recommend this before water fights start outside for the summer!

Patty Rooks, Senior Scientific Consultant Praxis Science Outreach Society.

Patty Rooks, senior scientific consultant PRAXIS, “Connecting Science To The Community.” Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: 12 826 11th Street SE, Medicine Hat, AB, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca.

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