Liquid Nitrogen Fun!
About this Lesson by CUOS graduate students
Recommended Ages: Later Elementary, Middle School, High School
NOTE: This is really a Wandering Wizard activity, since it requires special materials. We include it as a lesson
due to popular demand but, if you find liquid nitrogen to try it yourself, BE CAREFUL!
Try looking in the Yellow Pages or similar references under “Gas - Industrial & Medical.”
Guiding Questions:
What is liquid nitrogen?
How do different materials behave under extremely cold
temperatures?
Objectives
Concepts:

Liquid nitrogen is made from nitrogen gas.
Principles:






A gas can be cooled and pressurized to form a liquid.
A liquid can be warmed to form a gas.
Nitrogen gas can be pressurized and cooled down to make “liquid nitrogen.”
Things dipped in liquid nitrogen become very cold.
Cold and brittle material often shatters if “smashed” or pressured.
Some materials get stronger when cold; some materials get brittle.
Facts:



You can see evidence of the cold nature of liquid nitrogen by observing formation of ice
crystals and “feeling cold.”
As liquid nitrogen is exposed to the air, it warms up and we can see its transition from a
liquid to a gas.
Things dipped in liquid nitrogen get VERY cold!
Skills




Hypothesizing
Observing
Noting Cause-and-Effect Relationships
Drawing Conclusions
Materials
Note: Some of these are specialized materials.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Copper Pennies (post-1985)
Balloon
Banana
Mixing Bowl
Dry Ice
Flower
Goggles
Hammer, nails and wood board
Ice Cream Mix - Here’s one recipe
Liquid Nitrogen
Strong Mixing Spoon
Tongs
Gloves
Water
Whatever else you can think of to freeze and smash
Room Preparation
Set up chairs and desks in a semi circle so that all students can see the demonstration.
Safety Precautions
Need to be careful when handling nitrogen and extremely cold materials, which can cause frostbite
or damage eyes. Also, be sure that everyone is wearing goggles to protect their eyes from flying
pieces when smashing things. Keep faces away from bowls of nitrogen, which poses a suffocation
hazard due to its oxygen displacement characteristics.
Procedures and Activity
INTRODUCTION
1. Understanding liquids and gases
o What is a liquid?
Share examples like water, milk and soda. All are free flowing. They have a definite
volume. They take the shape of their containers.
o What is a gas?
Share ideas including oxygen, nitrogen, and carbon monoxide. Gases have no
definite shape or definite volume.
o What is liquid nitrogen?
Liquid nitrogen is made from cooling and pressurizing nitrogen gas.
2. Properties of liquid nitrogen
o All materials have properties—their own traits and characteristics.
o Pour some liquid nitrogen into a mixing bowl. What properties do we see?
 Cold
 “Smokes”
 Visible Liquid
 Seems to Disappear
Can we see liquid nitrogen turning into a gas? What is happening?
The liquid warms up and becomes a gas we cannot see. Pour some more liquid
nitrogen into the bowl and watch the process happen. The liquid seems to disappear.
o What happens when materials get very cold?
Liquid nitrogen is very cold. If we pour it over things or dip things into it, they get
cold. See what happens as we do “Smashing Experiments.”
o
ACTIVITY
Smashing Experiments
Smashing things is the first phase. Dip various things into liquid nitrogen until frozen and see what
happens to them. Many materials will become brittle when cold. Others will get stronger when cold.



Flowers will crumble in your hands.
Freeze a copper penny for a good long time, then smash it with a hammer and watch it
shatter into pieces.
Freeze a banana and then hammer a nail into a board with it.
Why do some things get brittle while others, like the banana, seem to get stronger?
Other Experiments




Take out a piece of dry ice and knock it around on the
floor or table top. Why does it glide so easily?
Put a piece of dry ice into a rubber glove and seal it. What
happens and why? Now take the same glove and put it
over a container of liquid nitrogen. What happens now?
Put a piece of dry ice into a glass of water. Notice how it
looks like a drink from a horror film. When the dry ice is
gone, drink the water. What does it taste like? Why?
Blow up a balloon and put it over the container holding the dry ice. Or you can shove the
balloon into a container of liquid nitrogen. What happens? Why?
Making Ice Cream
The Process
A Simple Recipe
Put the ice cream mix into a bowl, pour in some liquid nitrogen, and
stir.
2 cups whipping cream
Continue stirring and adding liquid nitrogen until the mixture is thick. 2 cups light cream
Why do you need to keep stirring?
4-8 tsp vanilla flavoring
Eat the resulting ice cream.
1 cup sugar
Closing - Original Questions
Ask again:
What is liquid nitrogen?
How do different materials behave under extremely cold temperatures?
Evaluation
Ask students to describe liquid-to-gas transitions and gas-to-liquid transitions. Have students share
what they observed and learned about liquid nitrogen and materials that become very cold. Review
what they observed from smashing things, doing activities and making ice cream. Listen for evidence
that they understand the effect of cold temperature on materials.
Extension Ideas
Explore the properties of liquid nitrogen by conducting more experiments and researching to learn
about pressure versus temperature relationships, liquid to gas transitions, and insulating properties of
gas.
Careers Related to Lesson Topic




Physicist
o Career Presentation- John Nees
Chemist
o Tour - U of M Chemistry Department
o Wizard - Whiz Bang Chemistry
Chemical Engineer
o Tour - U of M Chemical Engineering
Mad Scientist!