Egg in a bottle
Since Easter is coming up, here is another egg experiment! I hope everyone panic bought extra eggs.
So for today... how can you get a boiled egg into a bottle without breaking it or the bottle?
This experiment is very easy and demonstrates the principal of air pressure and how gasses change when heated and cooled. When a gas heats up it expands, and the pressure goes up. When it cools it contracts, and the pressure goes down.
To get your egg into the bottle you need:
- a boiled egg, with the shell removed
- a bottle, with a neck slightly smaller than the egg
- a little oil
- a piece of paper folded so it will fit through the opening of the bottle
- a match
Step 1: Rub a little oil around the rim of the bottle
Step 2: Place the boiled egg near you on the table, next to the bottle so you can grab it fast
Step 3: Light the piece of paper and drop it into the bottle, then quickly place the egg on top of the bottle
Step 4: Delight in the amazement of your children as they see the egg pop into the bottle!
(Note - in the video our egg comes apart. My daughter couldn't help herself and took a little nibble from the egg, so it wasn't entirely smooth on the surface! If you don't eat some of the egg the whole thing should go in. Kids and science hey. They were still pretty excited.)
How did it work? When the lighted piece of paper was in the bottle, it heated up the air inside. This caused it to expand. When the egg was placed on top, the air couldn't get out anymore - so once the air inside the bottle began to cool it contracted and the air pressure in the bottle went down. The air pressure outside of the bottle was higher than inside - so it "pushed" the egg into the bottle.