Hooked on Science: Make a cloud in a bottle

We see them in the sky all the time, but have you ever made your own cloud? You can, and all you need are a few items from around the house.

Materials

* 2-liter bottle

* Water

* Matches

Instructions

STEP 1: Add a small amount of warm water to the 2-liter bottle.

STEP 2: With an adult present, light a match, and then quickly place the match into the bottle. Screw the cap onto the bottle.

STEP 3: Using your hands, squeeze the sides of the bottle about six times.

STEP 4: Squeeze the bottle one more time, but this time don't let go for a few seconds. Look closely at the bottle and then let go.

Explanation

You just created an atmosphere perfect for cloud development. The water vapor inside the bottle attached to the smoke particles produced by the match. When you squeezed the bottle you increased the air pressure. When you let go you decreased the air pressure, which cooled the air and created the cloud in your bottle.

Jason Lindsey is a science outreach educator with Hooked on Science. Check out his website www.hookedonscience.org for webcasts and experiments that might get you hooked on science. Send him your science questions at jlindsey@hookedonscience.com. More science experiments can be found at www.semissourian.com.