Halloween Physics III: The Physics of Dry Ice

Whether it's a mist-filled graveyard or bubbling potions in the Haunted Science Lab, the addition of smoke and fog can certainly add to the mood of the holiday. The smoke machines used to create these effects utilize dry ice, or frozen carbon dioxide, combined with water to create the needed fog.

Dry ice is a material which undergoes sublimation, a phase transition directly from solid to gas, at room temperature. This provides it with a number of rare and useful properties, not the least of which is the ability to keep material cool without leaving melted water to clean up.

For more information on how dry ice works, check out our new feature The Physics of Dry Ice on About Physics. Learn how dry ice is created, how to safely handle it, and different uses for dry ice.

In addition, check out these About Chemistry articles about dry ice:

• How To Make Non-Toxic Smoke or Fog
• Chemistry of Smoke Machines
• Carbon Dioxide Structure