This experiment shows how clouds are formed as warm air is cooled. You will need a large glass jar, a small metal baking tray and some ice.

--> See the flash animation

You will need
a) a glass jar,
b) some hot water; and
c) a metal baking tray with some ice

Steps

1. Pour 2.5 cm of hot water into the jar. (Do not use boiling water as this may crack the glass.)

2. Place some ice cubes in the baking tray and put the tray on top of the jar.

3. As the air inside the jar rises and is cooled by the ice, the water vapour it contains condenses into droplets.