We just can’t get enough of dry ice at Halloween. It’s perfect for many bubbling, spooky science activities. One favorite demonstration is the Dry Ice Crystal Ball Bubble. This activity will have your audience oohing, ahhing, then asking to do it again. First, purchase a few pounds of dry ice at your local grocery store. Bring gloves and a styrofoam cooler with you. Be careful – dry ice is -110 degrees below zero and can burn skin.
Cut a strip of cloth about 1 inch wide and 18 inches long (an old t-shirt works well). Soak the cloth in a solution of Dawn dish soap or use your favorite recipe for making bubble solution. Make sure that the cloth is completely soaked. Use a smooth-lipped bowl and fill it half way with warm water. Using gloves or tongs, add enough dry ice to the water to produce a nice fog. Remove the strip of cloth from the dish soap and carefully pull the strip across the rim. The goal is to create a soap film that covers the top. It also helps to have the rim wet before you start. This may take some practice until you get the technique mastered. Remember that a bubble’s worst enemies are dirt, oil, and rough edges. Your patience will pay off in the long run.
For more about the science behind the Dry Ice Crystal Ball Bubble visit the experiment page.