Balloon in a Bottle: Air Pressure Science

Is it possible to blow up a balloon inside a bottle? Let’s find out with this interesting experiment!


  • A plastic bottle
  • A balloon
  • A pin or needle
  • Some tape


  1. First, stretch out the balloon.
  2. Once it’s stretched out, place the deflated balloon in the bottle and wrap the neck around the bottle opening.
  3. Try blowing up the balloon. It won’t work. But what if we made a hole in the bottle?
  4. Pierce a hole in the side of the bottle with the pin. Now try blowing up the balloon again, without covering the hole. It works!
  5. Quickly cover the hole with your finger and put a piece of tape on it. You will see that the balloon will not deflate even with its opening still open.
  6. Take away the tape and see how the balloon deflates again.
  7. Put your mouth on the hole and suck the air out. You will see that the balloon inflates again.

What just happened?

You are reducing the air pressure inside the bottle by sucking out the air. The balloon inflates to equalize the air pressure.

Isn’t interesting! Hope you liked this experiment!