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How to Make an Ice Crystal Ball

Kids can learn about the properties of surface tension and how gas expands in this dry ice crystal ball experiment. It is so named because the bubble formed by the expanding soap film looks like a crystal ball filled with fog. The dry ice must be handled by an adult, but kids can take part in other aspects of the experiment. Creating the dry ice crystal ball involves water, dry ice and soap. The bubble doesn't last very long but can be recreated over and over.

Things You'll Need

Dry ice
Gloves
Hammer
2 plastic bowls
Water
Dish detergent
Rag

Instructions

- 1
  Purchase dry ice. Grocery stores, restaurants and warehouses frequently use dry ice in packaging. If you look around at local retailers you'll find one offering dry ice for sale or willing to part with some from their packing crates.
- 2
  Fill a bowl with some water and a few drops of dish detergent. You should only need a cup or two of water. Mix up the soap and water to make it sudsy.
- 3
  Fill another plastic bowl with a cup or two of water.
- 4
  Break the dry ice into small chunks with a hammer.
- 5
  Place a piece of dry ice into the plain water. Wear gloves when handling the dry ice. It can burn your skin. Fog will start erupting from the bowl of water and spilling over the sides. This fog is carbon dioxide (CO2) gas.
- 6
  Wet a rag in the soapy water. Get the rag good and sudsy with soap.
- 7
  Pull the wet rag over the lip of the plastic bowl with dry ice and water to form a film. This film traps the gas in the bowl. The gas slowly builds up and pushes the film outward in a sphere which looks like a crystal ball. Keep your crystal ball as long as possible or pop it to release the gas all at once. Repeat as you like.

Animals & Science