Materials Required:
- Cork
- Slender tube
- Lac or grease
- Glass bottle
- Large bowl
- A piece of cloth
Procedure:
- Drill a hole in the cork and insert the slender tube through the hole. Then fix the cork along with the tube tightly on the mouth of the bottle. Lac or grease can be used for making the joints air- tight. Keep one thing in your mind that the thinner the glass of the bottle, the better will be the success of the experiment.
- Now, turn the bottle upside down and hold it in such a way that the other end of the tube remains immersed in the water kept in a large bowl. Now, ask one of your members to rub his hands and hold the bottle. You will see some bubbles rushing from the mouth of the tube to the surface of the water and bursting out there.
- Now, do one more thing! Take a piece of cloth spread out in the sun and fold it to wrap it around the bottle. See what happens. What do you say? Some more bubbles come from the mouth of the tube and appear on the water surface, don’t they?
This is what happens:
It is so because the heat of the hands or the warmth piece of the cloth permeates through the air inside the bottle to cause it to expand. That part of the expanded air which cannot be contained in the bottle comes out through the tube and can be seen in the form of bubbles.
