# 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.

## Experiment Materials

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

# Experiment

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.