Find a puddle outside on the playground or sidewalk. Watch it for a few days. Does it get bigger or smaller? Mark the edges with chalk or small rocks. Does the puddle shrink more on cloudy days or sunny days?

Understanding the Water Cycle

Students will understand how evaporation and condensation work together to create the water cycle.

Playing with Puddles
Find a puddle outside on the playground or sidewalk. Watch it for a few days. Does it get bigger or smaller? Mark the edges with chalk or small rocks. Does the puddle shrink more on cloudy days or sunny days?

Build a Terrarium
Construct a small classroom terrarium and observe a miniature water cycle in action. Place a layer of soil in a large jar with a tight-fitting lid. Add a few small plants. Water the soil lightly and put the lid on. Have students watch the terrarium closely. Are there certain times of day when condensation forms on the walls of the terrarium? Keep notes in a daily journal.

Explore Evaporation and Condensation
How does water get into the air?
Rub a wet towel or sponge on the chalkboard. What happens to the wet spot over the next few minutes? Where does the water go? Wet the chalkboard again. What happens if you move air across the chalkboard (with a fan or a towel)? What happens if you heat the chalkboard with a lamp? Write down your observations.

How does water change from a gas to a liquid?
Find a heat-resistant dish with a lid. Put the lid in a freezer for 30 minutes. Meanwhile, use a hot plate to warm up the dish. Turn off the hot plate. Place the lid on the dish. What happens? Explain that the water droplets are like the rain that condenses in the atmosphere and forms clouds.