Background:
Students should be aware of the different types of clouds.  They should also have some knowledge of the water cycle.

Description:
this is a hands on lesson in which students will be creating a model of how clouds are formed over a body of water.

Materials:
A large clear plastic jar, a small metal tray, ice cubes, and hot water

Procedure:
Fill the plastic jar about 1/2 full of hot water.  Place some ice cubes on the metal tray, and place the tray on top of the jar.  As you do this procedure, explain to students that the warm water is a model of a lake that has been heated all day in the sun.  When you put the ice on top, explain that this is representing a cold front moving in over the lake at the end of the day.

Discussion:
Q.  What happens inside the jar?

A.  A "cloud" should form directly underneath the tray.

Q.  Why does this happen?

A.  Air and water vapor inside the jar next to the tray is cooled, condensing into water droplets.

Q.  How does this compare to how real clouds are formed?

A.  In the atmosphere, air rises, cools, and water vapor present in the air condenses into clouds.

Assessment:
Have students draw a picture, labeling the water cycle and what is happening inside the jar when ice cubes are added on top.

Extension:
ELA - Have students write an explanation of how a cloud forms in their journals.