Piece of paper
Conduct this experiment only with adult supervision.
Peel the shell off a hardboiled egg and place it on the mouth of a bottle to check if it falls inside the bottle. If it doesn’t, you are ready for the experiment. If it falls inside, choose another bottle that has a smaller mouth.
Now, ask an adult to light a piece of paper using the match sticks and drop it inside the bottle.
Immediately place the egg on the mouth of the bottle.
We can observe that the egg falls into the bottle.
How does this work?
This is due to air pressure. When the burning paper is dropped into the bottle, air expands rapidly. And when the egg is put on the top, closing the mouth of the bottle, the flame goes off, consuming the air and creating a vacuum. The air from outside the bottle pushes the egg inside, thus squeezing the egg in to the bottle.