Egg in a bottle is one of those magical experiments that will astound middle-schoolers. Add some drama showing that the mouth of the bottle is smaller than the egg.
Is it magic or science? If you get the egg into the bottle without touching it, can you get it out again?
- Eggs. The eggs shouldn’t be too big for the bottle mouth (The egg diameter should be less than 3/16 inch bigger than the bottle mouth)
- Pot with water to boil an egg
- Glass bottle like a fruit-drink bottle or any bottle with the mouth slightly smaller than the egg.
- Cooking Oil
- 3×3” Piece of paper
- Matches or lighter
- (Alternative to matches and a lighter is to pour hot water into the bottle to heat the inside of the bottle. Pour the water out and place the egg in its mouth.)
Getting the Egg out of the Bottle
- Volunteer to blow air in the bottle
- 1 Tablespoon Baking soda
- A ¼ cup of vinegar
- Egg in the bottle
What Mystery Are We Solving?
What will happen if you add a burning strip of paper to a bottle and place a boiled egg in the mouth of the bottle? Is it magic or is there a scientific explanation? If the egg is in the bottle, can you suck the egg out of the bottle?
The experiment requires adult supervision. Kids may accidentally burn their fingers or drop a burning match when lighting strips of paper. Have a fire extinguisher nearby.
When blowing air into the bottle the egg may pop out into the mouth of the blower. It’s best if this part of the experiment is done by older kids who won’t choke from fright if the egg pops into their mouth.
Be mindful that if the bottle has a defect, it may shatter with the heat. To be safe, wear goggles and gloves.
- Boil the egg in a pot. The water should cover the egg about an inch. Boil for about 5-8 minutes.
- Take the pot from the stove and wait about 25-30 minutes. Then immerse the egg in cold water to cool down.
- Lubricate the inside of the bottle mouth with some cooking oil to prevent the egg from breaking. (If the egg diameter is too big for the bottle mouth, it may also break)
- Peel the egg and place the pointed narrow tip of the egg in the bottle mouth. The egg now rests in the mouth but is too big to slide into the bottle.
- Fold the piece of paper into a strip that is small enough to drop through the bottle mouth.
- Light the strip of paper.
- Lift the egg and drop the burning paper into the bottle.
- Quickly replace the egg.
- Watch how the egg wiggles and is sucked into the bottle.
Getting the Egg Out Of The Bottle
- First, try sucking the egg out of the bottle. Nothing happens.
- Now blow air into the bottle with the egg.
- Be mindful because the egg will pop out of the bottle into the blower’s mouth.
- Turn the bottle over; the egg gets stuck in the mouth of the bottle.
- Turn the bottle on its right side and pour the baking soda and vinegar into the bottle with the egg.
- Now turn the bottle upside down over a container.
- The egg slides out of the bottle.
What Just Happened Here?
Air pressure physics pushes the egg into the bottle. The burning paper inside the bottle heats up the air. The excited air molecules expand by spreading out, making the air less dense inside the bottle compared to the colder air outside the bottle.
When the fire goes out, the air cools down inside the bottle and the air contracts creating a vacuum. The higher pressure of the colder air outside the bottle pushes the hardboiled egg into the bottle.
When blowing air into the bottle, the pressure increases when more air is blown into the bottle. To make space for the extra air, the air pushes the moveable egg out of the bottle.
The baking soda and vinegar create carbon dioxide, a gas that increases the air pressure inside the bottle. When the bottle is turned upside down, the pressure forces the egg out of the bottle.
What is the science of a raw egg being boiled and becoming a hardboiled egg? The raw egg contains globular proteins which are amino acid chains clumped together in individual spheres. Boiling egg forces the water and protein molecules to collide and break the amino acid chains apart. These amino acids form new networks with water molecules trapped inside the protein chains, changing the consistency of the egg from soft to hard.