(Notes on a portion of the presentation given at NCAR's Super Science Saturday, Fall 1998 and on the presentation at the University of Colorado sponsored Expanding Your Horizons Conference, Spring 1999)
These presentations use dry ice, soap, and a variety of gases to talk about bubbles, convection, and the various properties of gases.
To do everything you will need:
- Dry Ice
- gloves (for handling dry ice)
- hammer (to break off chunks of dry ice)
- ice cubes
- 10 gallon aquarium
- graduated cylinder
- clear glass bowl not more than 12 inches in diameter
- a bucket
- dish soap for homemade bubble or store bought bubble soap
- bubble wand
- food coloring
- hot water
- cloth strip
- ice cubes
- helium (you can buy canisters for blowing up balloons at target)
- funnel (try various sizes)
- propane (you can get bottles used in camp stoves at camping supply stores)
- lighter with a long wand (like used for lighting wood fires or camp stoves)
- plastic plate
- spray bottle
- plastic tubing (try an aquarium supply store)
- Big sponge and towel for cleanup
- large dish for dipping bubble wands
- duct tape (to hold tubing, funnels, and gas tanks together)
- long fireplace matches
- Why is it called DRY ice? Set a piece of dry ice next to a piece of water ice. Watch them "melt". What happens?
- Place a piece of dry ice and hot water in the bucket. Let everyone feel the smoke.
- Place dry ice and hot water in the aquarium to a depth of an inch or so. Blow bubbles into the aquarium and they will float on the layer of CO2. Light a match and dip it into the aquarium. Find the depth where the match is extinguished.
- Place dry ice and hot water in the glass bowl. Get the piece of cloth soapy and stretch a bubble across the top of the bowl by drawing the piece of cloth across the rim. Watch as the bubble expands and finally pops.
- Place dry ice and hot water in the graduated cylinder. Add a little soap. You will want to set this on a deep dish as it can get messy. I used a second 10 gallon aquarium.
- Connect the helium tank and the small end of a funnel with the plastic tubing. Dip the large end in bubble soap and turn on the helium. The bubble you blow will float to the ceiling.
- Connect the propane tank and the small end of a funnel with the plastic tubing. Dip the large end in bubble soap and turn on the propane. The bubble you blow will fall to the floor. Cut a hole in the plastic plate and put the lighter wand through so the plate acts as a shield for your hand while holding the wand. Hold you arm high and blow a bubble. As it falls light it on fire with the lighter!
Dry ice sublimates at -78.5C
Bubbles love humidity, so you may need a friend to constantly spritz the area with the water bottle in order to get the last two experiments to work.
Some ideas on this page taken from Steve Spangler's Halloween Science... Guaranteed to get Ooohs & Ahhhs! • WREN Enterprises, Inc. (303)798-2778 • © 1998 WREN Enterprises, Inc.