Egg in the Bottle Experiments
EGG IN THE BOTTLE
Experiment Procedure
- Light a strip of paper using a match or lighter.
- Drop the paper into the milk bottle or other glass container you are using (an Erlenmeyer flask works well). Quickly place the egg at the top of the glass container. The egg should be pulled into the container! To get the egg out just as quickly, blow into the bottle. The air you blow in will push the egg back out into your mouth (so maybe have a friend do this part instead).
- After you have removed the egg and cleaned out the bottle, try placing three birthday candles in one end of a new hard boiled egg. Make sure the candles are close enough together that they can fit in the opening of your bottle.
- Using matches or a lighter, light the candles.
- Hold the bottle upside down and insert the lit end of the candles/egg into the bottle. The candles should go out and the egg should be pulled up into the bottle!
Materials List
- Milk bottle or other glass container
- Hard boiled eggs (peeled)
- Matches
- Birthday candles
- Paper
- Adult supervision
How Does It Work?
To get the egg into the bottle in this experiment, you must use the physics of air pressure. When you insert the lit paper or birthday candles, the air molecules inside the bottle heat up. Heated molecules become excited and spread out, making the air less dense, and some of them will even escape from the bottle. The cooler molecules outside the bottle have a higher pressure because they are less spread out (or more dense) and are not in an excited state. Since they have a higher pressure, they literally push the balloon into the bottle.
To get the egg out, it’s much easier to force air into the bottle instead of sucking the egg out. Because the egg doesn’t create a perfect seal with the bottle (it’s rigid enough that the air will push the entire egg out of the way), the air you blow in goes around the egg. The new air you’re blowing in takes up space, and once it fills up the bottle, it has nowhere else to go but back out. Since the egg is in the way, the air pushes the egg out to make room for more air.
TAKE IT FURTHER! – BALLOON IN THE BOTTLE
Experiment Procedure
- Light a strip of paper using a match or lighter.
- Drop the paper into the bottle. Quickly place the balloon at the top of the glass container and watch as the balloon is pushed into the bottle.
- To remove the balloon, turn the bottle upside down and position the balloon so that the tied end is facing the mouth of the bottle.
- Insert the straw into the bottle next to the balloon.
- Grab the tied end of the balloon with your fingers, and it should easily slide out.
Materials List
- A clean milk bottle or other glass container
- A small water balloon (but make sure it’s large enough that it doesn’t fall into the bottle)
- Matches
- Paper
- A straw
- Adult supervision
How Does It Work?
Just like the Egg in the Bottle experiment, this experiment demonstrates how the physics of air pressure can be used to push the balloon inside the bottle. The same thing happens: when the air molecules inside the bottle are heated up, they become active and spread out, which means the pressure is lowered. Because the cooler molecules outside the bottle are not active and are closer together, they have a higher pressure.
This high pressure air literally pushes the balloon into the bottle.
Getting the balloon out is a little different, however. It’s not possible to blow air into the bottle to get the balloon out like you did in the first experiment because the balloon is not firm like the egg. You also can’t pull the balloon out because it creates a perfect seal, and if you pull hard enough,the balloon might burst. This time, you’ll need to use the straw to equalize the air pressure, which allows the balloon to be pulled out more easily.
Science Fair Connection
Observing and demonstrating the Egg in the Bottle is pretty cool, but this activity isn’t a science fair project yet. You can make it one by simply by identifying a variable (something that might change the outcome) in the experiment, then testing that variable, and correctly reporting the results. Think about some variables like these that you might test:
- Try using different temperatures to see if you can duplicate this effect (ice, warm water, or other things besides fire).
- Replace the egg with something else.
These are just a couple of ideas, but you aren’t limited to them! Come up with different ideas of variables to test and give them a try. Remember, you can only change one variable at a time for each test. For example, if you are testing different water temperatures, make sure that all other factors in the test remain the same!
