Introduction

Better grab your umbrella; it’s starting to rain!

Objectives

 To demonstrate how clouds can produce rain

Materials

• Clear plastic cup (five ounce or larger)
• Water
• Shaving cream
• Food coloring (several colors)
• Small cup or dish for each color
• Wooden craft stick (or something for stirring)
• Eyedropper or pipette

Procedure

Fill the clear plastic cup approximately three-fourths full of water. Pour some water into a smaller cup and put three drops of food coloring in it. Stir. Repeat this step for each color. Squirt some shaving cream onto the clear water (larger cup) covering the entire top. It should look like a big fluffy cloud. Do not stir. Now use the dropper to drizzle colored water onto the shaving cream until the colored water begins to sink through the shaving cream.

Conclusion

The shaving cream sits on top of the water because it is less dense than the water. The colored water slowly seeps through the shaving cream and looks like a rainstorm. Clouds form rain when water droplets condense out of the air and gather more water and become larger. After a while, the droplets grow into a mass where they cannot stay in the cloud because they are too heavy. Rain will continue as long as the conditions are right to make clouds and the water droplets grow heavy enough to fall to the ground.