# Milk Bottle & Egg Demo

SKU #BOT-800
(6 reviews)
Availability: In Stock
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It's all about Air Pressure! - A Classic Demonstration!

Description

Use this sturdy glass milk bottle for an egg-cellent demonstration of air pressure. All you need is a hardboiled egg and a little bit of fire. If you drop some lit paper inside the milk bottle and then place the egg on top, the fire goes out and the egg is mysteriously pushed into the bottle, intact! Warm air expands, cool air contracts - it's the cooling of the heated air inside the bottle that allows the atmosphere to "push" the egg inside.

Read more on our Blog - Science Never Sucks | Milk Bottle and Egg

Video

Lesson Ideas

Reviews

6 reviews
Egg in the Bottle
Mar 1, 2019
This demonstration is beneficial when discussing air pressure, how heated gases expand, atmosphere pressure, pressure always goes from high to low in an attempt to equalize, and how the number and/or velocity of molecules in a container influences the pressure exerted by the gas. In this demonstration, the boiled egg is placed on the top of the bottle. Nothing happens because the pressure inside the bottle is equal to the outside air pressure. When the gas inside the bottle is heated by the flaming material placed in the bottle, the gas expands escaping (due to the molecules having a greater velocity) from the bottle so there are fewer air molecules remaining in the bottle. This can be seen as the egg moves up and down. When the flame is extinguished, the egg seals the bottle so air cannot return into the bottle, thus you have fewer molecules than before. Since this can be viewed as a gas in a rigid container, the pressure decreases as the molecules inside slow down, reducing the inside pressure. The atmospheric pressure has not changed but is now greater than the inside pressure, pushing the egg into the bottle (not that the air is contracting, although it would if the air was in a flexible container such as a balloon. To get the egg out one must increase the amount of air in the bottle to where the pressure inside is now greater than the outside. This can be easily done by inverting the bottle so that the egg is in the neck of the bottle and then blowing air into the bottle while it is upside down, increasing the number of molecules, more pressure. I find that using a small amount of cotton dipped in a little bit of rubbing alcohol and set on fire reduces the amount of ash that remains. People are more likely to be volunteers to blow into the bottle if there is much less ash. If you have liquid nitrogen available, you can simply place the egg on top of the bottle and insert the bottle, upright, into the liquid nitrogen. Same reasoning as before. I've seen the egg in the bottle demo performed with a raw egg which has been pithed at both ends using. Ideally, the insides are pushed into the bottle while the egg shell remains at the top. I have not yet been successful with this, yet! We include this demonstration in our outreach programs dealing with the topics of pressure and/or properties of gases. You can easily purchase these bottles at the grocery filled with milk. Enjoy the milk, wash out the bottle (don't return for a refund), and then use them for this activity. The bottles are thick and a hard boiled egg sits perfectly on the mouth of the bottle.
Kenneth Lyle

2   0

My first day of chemistry class!
Feb 9, 2019
It was this demonstration that my high school chemistry teacher performed and thus began my journey into falling in love with this science! Once I began my career as a chemistry teacher I searched hard to find this very same bottle that my chemistry teacher used. Thank you EI for having it!! Yours is perfect, great strength and length for excellent visibility of the egg being sucked into the bottle. And... if you're as daring as my high school teacher was, you can create enough pressure with your mouth to remove the egg!
Chemical Kim

1   0

First Day of School!
Mar 7, 2017
I loved doing this demonstration on the first day of school to get my students talking about science. Many of them knew hot to get the egg INTO the bottle, but getting it out, was always a different story. You will get some pretty "creative" responses on how to do it. When the tried their ideas, it usually led to lots of laughs (something you need in middle school on the first day). When I led them to the answer on how to remove the egg from the bottle, they LOVED it!
Jody Hodges

0   0

Steps of the Scientific Method
Sep 7, 2015
I used the bottles to assist the students in setting up an experiment using all the steps of the Scientific Method. Using water and pebbles the students worked through the steps while causing water from the bottom to the top of the bottle. They loved identifying and going through the steps while learning about water displacement.
Becky

0   0

Sturdy bottle
Sep 28, 2013
I've used these for several years now for the egg demo. It works better than a flask because it's heavier and sturdier, so it's less likely to tip over when the egg falls into the base. Not so easy to clean - you have to cut the egg into pieces while it's in the bottle to get it out - but well worth it.
Rachel

0   0

teacher-science & chemistry
May 29, 2012
Great for demonstration. Students enjoy tryign to determine the "why" and are even more intrigued in getting the egg out so easily.
julie Luehmann

0   0

### NGSS

This product will support your students' understanding of the Next Generation Science Standards (NGSS)*, as shown in the table below.

 Elementary Middle School High School K-ESS2-1 Students can use and share observations of local weather conditions to describe patterns over time. Students can apply knowledge gained from the Milk Bottle demonstration to understand the power of air pressure and its effects on weather. (See Lesson Ideas) K-ESS3-2 Students can ask questions to obtain information about the purpose of weather forecasting to prepare for, and respond to, severe weather. Students can apply knowledge gained from the Milk Bottle demonstration to understand the power of air pressure and how air pressure is a factor in forecasting weather. 2-PS1-2 Students can analyze data obtained from testing different materials to determine which materials have the properties that are best suited for an intended purpose. 3-ESS2-1 Students can represent data in tables and graphical displays to describe typical weather conditions expected during a particular season. Students can apply knowledge gained from the Milk Bottle demonstration to understand the power of air pressure and its effects on weather/seasons. (See Lesson Ideas) 3-PS2-1 Students can use the Milk Bottle in a plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object. 5-ESS2-1 Students can develop a model using an example to describe ways the geosphere, biosphere, hydrosphere, and/or atmosphere interact. Students can apply knowledge gained from the Milk Bottle demonstration to understand the power of air pressure and how it interacts on Earth. (See Lesson Ideas) MS-PS2-2 Students can use the Milk Bottle to plan an investigation to provide evidence that the change in an object's motion depends on the sum of the forces on the object and the mass of the object. MS-ESS2-6 Students can use the Milk Bottle to develop and use a model to describe how unequal heating and rotation of the Earth cause patterns of atmospheric and oceanic circulation that determines regional climates. (See Lesson Ideas) HS-ESS2-4 Students can apply knowledge gained from the Milk Bottle demonstration to use a model to describe how variations in the flow of energy into and out of Earth systems results in changes in climate. (See Lesson Ideas.) HS-ESS2-5 Students can use the Milk Bottle to plan and conduct an investigation of the properties of water. (See Lesson Ideas)

Suggested Science Idea(s)

K-ESS2-1
K-ESS3-2
2-PS1-2
3-ESS2-1
3-PS2-1
5-ESS2-1
MS-PS2-2
MS-ESS2-6
HS-ESS2-4

The Milk Bottle can be used in an air pressure demonstration to show students the dramatic effects of changing air pressure.

Use this sturdy glass milk bottle for a demonstration of air pressure. All you need is a hardboiled egg and a little bit of fire. If you drop some lit paper inside the milk bottle and then place the egg on top, the fire goes out and the egg is mysteriously pushed into the bottle, intact!

Warm air expands, cool air contracts—it's the cooling of the heated air inside the bottle that allows the atmosphere to 'push' the egg into the bottle.

HS-ESS2-5

The Milk Bottle can be used in an investigation to explore water surface tension and static equilibrium. Place a piece of netting fabric (included with Milk Bottle item BOT-800) over the mouth of the milk bottle. Secure it with a rubber band. Pour water into the milk bottle. Quickly invert the bottle. The water will not pour out.

* NGSS is a registered trademark of Achieve. Neither Achieve nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of, and do not endorse, this product.

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