Water Balloon In A Bottle!

What do I need:

• A milk bottle or jar
• Piece of paper
• Matches

How do I do it?

STEP1 – Fill up your water balloon with water and tie it up! Make sure your water balloon is too big for the top of your bottle so you can’t just push it in!

STEP2 – We’re going to use air pressure to get water balloon into the bottle.

WARNING: Make sure you have an adult to do this experiment with you and take all the sensible safety precautions.

STEP3 – Light the piece of paper and drop it into the bottle. While it’s still burning place your water balloon on top of the flask.  

STEP4 – Don’t blink! Plooooooop! The water balloon looks like it gets sucked in!

Why does this work? When the burning paper goes in, the air inside the flask heats up and expands (gets bigger).  Once the balloon is placed over the top the fire will run out of oxygen and go out and the air will cool and contract (gets smaller) “sucking” the balloon in.  When the air inside the flask cools down the pressure inside the flask will be lower than in the room so really it’s the air pressure of the room pushing the water balloon in! Find more fun scien