Experiment by observation! Let’s understand the effects of air pressure: The egg and the bottle
- Hard-boiled egg
- Bottle with a wide mouth
- Box of matches
Follow these steps:
1. Take an egg and boil it until it is hard. Make sure it cools down before you continue. Ask an adult to help you or at least supervise while you cook the egg. Once the egg is cold, peel the shell off.
2. Now, take the newspaper and tear a page in strips. Insert the strips into the bottle and put a lighted matchstick inside (always with adult supervision). Quickly take the egg and place it on the mouth of the bottle. Observe what happens! The egg goes into the bottle by itself. Magic? No, it’s science.
3. And how do we get it out? Turn the bottle upside down and blow into it. Bear in mind that the egg will pop out when you do this!
That’s unbelievable! How can it be? Air pressure is the answer. When you light the fire, the oxygen in the bottle is consumed. When the egg is placed on the mouth of the bottle, the air inside the bottle creates a vacuum that sucks the egg into the bottle.
Shortly afterwards, the fire dies out and the air inside the bottle will cool down and the pressure inside it will decrease. The egg is forced out of the bottle when you blow into it to increase the air pressure within it.