Why Does Metal Scream When It Touches Dry Ice?

Spoons are used to demonstrate Bernoulli's principle with dry ice.
••• spoon image by Jim Mills from Fotolia.com

Dry ice is one of the few substances that sublimes, or vaporizes from a solid state. The noise produced when a metal touches dry ice is an effect of the Bernoulli principle.

Bernoulli's Principle

Bernoulli's principle describes what happens when a gas moves. There is a pressure drop associated with the increase in the speed of a fluid. The dry ice vaporizes into carbon dioxide gas when a comparatively warm metal comes in contact with it, creating a change in pressure.


Because metals are good conductors, they transfer ambient heat to the surface of the dry ice. This increases the rate of vaporization of the dry ice. As more and more gas is created, it pushes through the points where the metal touches the dry ice, creating a pressure drop that draws the metal and dry ice together again.


As the metal is pushed up by the evaporated gas and drawn back down by the pressure drop, it will vibrate quickly enough to hear an audible noise. Reeds in woodwind instruments operate under the same principle. Depending on the conductivity of the type of metal, the frequency will be different.

Related Articles

How to Calculate the Temperature Drop Due to a Pressure...
Why Does Citric Acid Produce Electricity?
How to Convert GPM to Cooling Rate in Tons
What Causes Convection Currents on the Mantle?
Three Ways to Melt a Rock
What Causes the Thermosphere to Be So Hot?
How to Convert CMH to BTU
How to Calculate the Gas Loss in a Pipe
How to Convert CV to GPM
What Are the 2 Types of Barometers?
Relationship Between Electricity & Magnetism
Do Winds Always Blow From High Pressure to Low Pressure?
What Causes Gas Pressure?
What Makes an Ice Cube Melt?
How Does Plate Tectonics Affect the Rock Cycle?
What Happens After Water Vapor Condenses?
How to Make Easy Dry Ice
How Does Elevation Affect Weather?
How Many Types of Welding Are There?
How Does a Stratovolcano Erupt?