Bend water with a balloon
You will move a rubbed balloon near a thin water stream without touching it. The water can bend towards the balloon, but a wide rushing stream makes the effect harder to see.
- Science
- Explorer
- About 10 minutes
Grown-up needed: yes for setup, nearby supervision and handling water or small items
What you need
- A balloon
- A woolly jumper or cloth
- A tap with a thin stream
- A towel
- A grown-up
The rule
Do not touch the water.
How to do it
- Ask a grown-up to inflate the balloon and set a very thin tap stream.
- Rub the balloon against the woolly cloth.
- Hold it away from the water and nearby electrical things.
- Move it slowly towards the stream without touching it.
- Observe which way the stream bends.
- Ask the grown-up to turn off the tap after the comparison.
Why it works
Rubbing can transfer electric charge between the cloth and balloon. Water molecules have an uneven distribution of charge, so they can turn and respond to the balloon’s electric field. That response can pull a thin stream sideways without direct contact. A fast, thick stream is harder to deflect because more moving water must change direction. The balloon’s charge can also leak away, especially in damp air, making later attempts weaker.
Make it harder
- Use less rubbing before the attempt.
- Start farther from the stream.
- Compare two stream widths while keeping balloon distance similar.
Ask Taz
- Why can a balloon pull water without touching it?
- Why does a thin stream bend more easily?
- Why does the effect weaken after waiting?
For grown-ups
Stay with the balloon and water, remove burst fragments immediately and keep them away from younger children. The comparison should use little water and finish promptly. A child can practise observing force without contact. Ask at dinner: “How could you tell whether distance or stream width made the biggest difference?”
Taz is an AI and can be wrong, so stay close by. Read how safety works on Taz.
Show us yours
Film your hands and what you made, not your face or name. Ask a grown-up before posting anywhere else.
Questions parents ask
Can we use what we already have?
Start with the listed household materials. Keep the basic setup small and ask a grown-up to choose suitable items before beginning. The stated time is an estimate, so let the observation decide whether you need longer.
What should we record?
Note the prediction, the result and the one thing you changed. Keeping those separate helps a family discuss what happened without turning an activity into a competition.
Must the result be shared online?
No. A conversation at home is enough. If you choose to share, keep identifying details out and follow the grown-up permission line above.
More to try
See all Taz Challenges, or look through the science labs. One place for every why. Ask for early access at aitaz.com
Try it in 3D: Static electricity.