How to Make a cloud, then make it disappear
This video features a really cool science experiment that is easy to do and fun to watch. Items you will need are a plastic 2-liter bottle with a sports bottle type cap (the kind you pull up on in order to sip liquids through the top), about a quarter of a cup of water and two matches. First, take the cap off the bottle and pour the water into the bottle before putting the cap back on the bottle. Then, simply open the pull top on the cap (so that when the bottle is squeezed and released air is inhaled and exhaled by the bottle) and then light a match. Quickly blow the match out and then squeeze and release the bottle so that it "inhales" the smoke. Once the smoke is inside close the cap. In a dark room, hold the bottle up to a light and squeeze and release to watch the "cloud" inside appear and disappear. When you are done, uncap the bottle and be amazed by how much smoke comes out!