Egg In A Bottle

Chemistry, Physics:	Air Pressure, Vacuums
Grade Range:	Elementary School
Format:	Hands-on

This demonstration can be done in a few different ways, all of which are provided below. This demonstration does involve fire, so do not allow students to handle the lighter or matches.

Materials

• 500mL Erlenmeyer Flask
• Matches or a Lighter
• Paper Strips
• Water

Method 1:

• Hard Boiled Eggs (Peeled)

Method 2:

• Hard Boiled Eggs (Peeled)
• Birthday Candles

Method 3:

• Balloons

Safety Precautions

Please read the Fire Safety section of the Demonstration Safety page before performing this demonstration.

This demonstration requires: safety goggles or glasses

Demonstration

Method 1

1. Hold a strip of paper by the top and light the bottom of it. Drop the strip of paper into the Erlenmeyer flask and quickly place an egg on top.
2. While the paper burns out, point out to any students at the table that the egg is adjusting slightly to let the hot air leave the flask. Once the paper stops burning, wait and watch as the egg is sucked into the bottle!
   • If the egg stayed whole while being sucked in, then light a second paper strip and drop it in the flask. Quickly flip the flask over, being careful to have the egg roll to the top, and the egg will be pushed out!
   • If the egg did not stay whole, then empty the flask out into a trash can. If needed, rinse the flask out before repeating the demonstration.

Method 2

1. Stick 1-2 birthday candles into the bottom side of an egg. Hold the egg in place and light the candles, and once they are lit place the mouth of the Erlenmeyer flask over them and the egg.
2. Allow the candles to burn out, and during this time point out how there is air escaping the flask around the egg. After the candles burn out, the egg will be sucked upward into the flask!
   • If the egg stayed whole while being sucked in, then light a paper strip and drop it in the flask. Quickly flip the flask over, being careful to have the egg roll to the top, and the egg will be pushed out!
   • If the egg did not stay whole, then empty the flask out into a trash can. If needed, rinse the flask out before repeating the demonstration.

Method 3

1. Light a paper strip and drop it into the Erlenmeyer flask. Take a balloon and stretch it over the top of the flask. While the strip is still lit, the balloon will look like it is inflating!
2. Once the strip goes out, have the students watch as the balloon "deflates", but then "inflates" inside of the flask! Can they guess why that happens?
3. Make a few small water balloons. light a paper strip and drop it into an Erlenmeyer flask. Quickly put on of the water balloons over the top. Once the strip goes out, it will be pulled into the bottle!
4. Light a second paper strip and drop it into the flask. Quickly flip the flask over, being careful to have the water balloon roll to the top, and the water balloon will be pushed out!

Why This Works

Pressure is when a force is applied over an area. Air Pressure is the pressure that the air around us applies. The amount of air pressure we feel depends on three things: how much mass the air has, how much energy it has, and how much space there is for the air. We can see these affects with any of the three methods for this demonstration.

When we have the paper or the candles burning in the Erlenmeyer flask, they are heating up the air and giving it more energy. This increase in energy causes the air to try to take up more space, which is why we hear the air squeezing out past the egg or water balloon. Even though there is less mass in the flask, the air inside has enough energy to push back against the air outside. This is why the balloon that is stretched over the top will "inflate" while the paper is burning inside. Once the paper or the candles goes out, however, then the air inside starts to lose energy. This means the air will take up less space, and there will be some empty space inside the flask. This empty space is called a Vacuum, and the air outside the bottle will try to push more mass into the vacuum. This is because the air inside the flask has low air pressure, and the air outside has high air pressure. The outside air will push the egg or water balloon into the flask, or cause the balloon stretched over the top to "inflate" into the flask!

Additional Information

• This demonstration pairs well with the Marshmallow Smashies, the Magdeburg Spheres, Crush The Can, and the Cartesian Diver demonstrations.