Egg in the Bottle Mystery

Overview of the Lesson

A. Date: 4/20/01

B. Time and Length of Lesson: 20 minutes

C. Group Structure: 21 students whole group around a desk in the front of the

classroom

D. Lesson Topic: The egg in the bottle mystery

E. Grade Level: 3r~ grade

Intended Student Learning Objectives

Students will observe the teacher physically try to make an egg fit into a glass

bottle.

Students will observe how an egg magically slips through the opening of the

glass bottle when a heat source is added.

Students will solve the mystery of why adding a heat source causes the egg to

slip through the opening of the bottle.

Content to be Covered

The egg in a bottle mystery

Air pressure principles

Instructional Materials

3 hard-boiled eggs (so that the experiment can be done 3 times)

A glass bottle

A hot pot

An electrical outlet

Boiling water

.Pot holder

ALTERNATE METHOD FOR EXPERIMENT

3 hard-boiled eggs

A glass bottle

A book of matches

A piece of paper

Activity and Procedure

A. Motivation and Introduction

"Boys and girls, who are we reading about that can perform magic tricks and

spells? (Harry Potter) Well Miss Butz can perform a magic trick too. Do you want to

see?"

B. Development

"Let's see if this egg will fit in the glass bottle. (place the egg on top and gently

try to push it into the bottle, it should not fit, pass the bottle around to students and

have them try, it should not fit for them either) Well, what if I told you I knew a way

to make this egg slip into the glass bottle without me touching it, you would think I

was a magician right? Well, let's watch." (teacher: have the hot pot boiling water

already boiled before execution of the experiment, place the boiling water in the glass

bottle, let stand for a minute or two, after that minute of two the bottle should be very

hot, use the pot holder to pick up the bottle and dump the hot water back into the hot

pot, after all the water is out, immediately place a shelled, hard-boiled egg skinny side

down on the open rim of the glass bottle, watch what happens) "What just happened

boys and girls?" (the egg got sucked down into the glass bottle).

ALTERNATE METHOD FOR EXPERIMENT (teacher: set a shelled, hard-

boiled egg on the open rim of the glass bottle, first have students try to physically

push the egg into the bottle (tell the students not to push too hard, the egg shouldn't

slip through), then take the egg off the open rim and place it readily accessible at your

side, rip a section of paper off from the big sheet, light a match and set the smaller

piece of paper on fire, and quickly insert the paper into the glass bottle, just as quickly

place the egg on top of the open rim of the glass bottle, watch what happens) "What

just happened boys and girls?" (the egg got sucked down into the glass bottle).

"Can anyone guess how Miss Butz made the egg slip into the glass bottle?" (take

a few student responses to assess their prior knowledge). Explain the real reason to

them. "The egg is too large to fit into the bottle by itself, so we need to give it a little

help. When we sit the egg on top of the bottle, it is balanced there because the air

pressure pushing down on the egg, the air pressure pushing on the sides of the egg,

and the air pressure pushing from the bottom of the egg, or the inside of the bottle are

all the same, equal, in balance. Once we added the hot water (or flame) to the bottle,

the air became warmer and the temperature rose. Warm temperatures make air

expand or get larger. When this happens, the air grows too big to fit into the bottle,

so it wants to escape or get out. But since there is an egg blocking the exit of the

bottle, the air must push its way passed the egg, this is why the egg bounces a little.

Now that all of the extra air left the bottle, the original air that was in there to start

with wants to get back into the bottle, but the egg is still in the way, so all of the air

that is outside the bottle pushes on top of the egg in order to get back in the bottle.

That is how the egg gets sucked into the bottle." (teacher: to get the egg out of the

bottle, just turn the bottle upside down, make sue the egg is up against the rim of the

bottle, place the open rim of the bottle in your mouth, make sure you seal your lips

around the rim and blow) "Boys and girls, why does blowing air into the bottle make

the egg come out?" (allow for student responses to assess prior knowledge) "The

reason the egg comes out when you blow air into it is because the air that is being

blown in is hot, this air causes the air already in the bottle to expand and want to

escape the bottle, but again the egg is in the way, so the air pushes the egg out of the

opening in order to get out of the glass bottle."

C. Summary and Closure

"Boys and Girls, is the egg in a bottle a mystery still or did we solve the mystery?

(No, we solved the mystery) How did the egg that wouldn't fit in the bottle at the

beginning of the lesson, fit into the bottle at the end of the lesson? Boys and girls,

this is a fun experiment, but remember DO NOT try it by yourselves, if you want

to try it, you MUST have a parent or an adult do it or do it with you because the

water (or fire) is very hot. Now you can pretend to be like Harry Potter and do

your own magic mystery tricks."

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