# Dry Ice Floating Bubbles

## This smoky pool might just float your boat... or bubble!

Exploration into the fascinating world of dry ice is never boring, and the same goes when you add in some bubbles! We've filled bubbles with dry ice smoke in our Boo Bubbles experiment, but did you know that bubbles will float on dry ice smoke like it was water? We'll show you how to do it and, of course, teach you the amazing science behind this very cool trick.

### Materials

• Large, clear plastic bowl
• Dry ice
• Heavy gloves / tongs
• Warm water
• Bubble wand
• Bubble solution (your favorite soapy mixture)

1. Pour warm water into a large, clear plastic bowl until about an inch of warm water covers the bottom of the bowl.
2. Use gloves or tongs to add a few pieces of dry ice to the warm water in the bowl. Take a second to observe the effect that is created when warm water and dry ice mix.
3. Using a bubble wand and some bubble solution, blow a few bubbles into the bowl. It can be a bit difficult, so be patient!
4. Once you get a bubble into the bowl, what happens? The bubbles float on the sea of smoke!

### How does it work?

You noticed that when you added dry ice to the water, a cloud of carbon dioxide and water was produced. But unlike smoke from a candle or fire, the dry ice smoke doesn't float. Instead, it settles onto the ground or, in this case, on top of the water. Why is that? The smoke is actually a combination of carbon dioxide gas and water vapor. This gaseous dry ice smoke is heavier than the air around it, so it sinks in the air rather than rising.

The same relation between air and dry ice smoke explains why the bubbles float on top of the dry ice smoke. The air exhaled into the bubble is less dense than the gases comprising the dry ice smoke, but slightly heavier than the air surrounding the bubble. So although the bubble doesn't float in the air, it does float on the heavier dry ice smoke.

 Archimedes suggests other floating objects PARRY    -  October 10, 2011 This user gave 5/5 stars how about measuring how much of the bubble is below "water level". A nice theme to talk about icebergs and bouyancy. Also thought it might be interesting to blow some nitrous oxide bubbles and some carbon dioxide bubbles using a food cream whip : any guesses about how much these bubbles would sink into the smokey carbon dioxyde/water vapours ? You can find thin extensions to cap the cream whip nozzle or make one to fit to the same pipette as shown in video, and of course you can find at least CO2 and N2O cartridges easily. Argon is available (and more expensive) for wine keeping (injection into head space of expensive bottles of wine keeps the wine free from oxidation!) Pregnant bubble blower seems to be my title by which Steve will remember me... Stacy R.    -  October 5, 2011 This user gave 5/5 stars Hi all, Nicely done. If you are not careful, you can melt your plastic bowl. The bubble is clearly kept floating by the support of the much more dense dry ice. It is lovely. I will be sure to incorporate it into my annual dry ice festival of science.

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