In the evaporation stage of the water cycle, water turns into water vapor. Give each student two identical jars and one lid that fits a jar and a metric ruler. Have them fill both jars with the same amount of water and then measure and record the water levels. Ask them to put the lid on one jar and place the jars next to each other in the same location, then have them measure and record the water levels for several days to see the effects of evaporation.
As water vapor rises, it cools in the upper atmosphere and condenses (turns into water droplets). Let your students experiment with this part of the water cycle. Give each student a quart-size glass jar and an aluminum pie plate containing several ice cubes. Have them put one cup of hot water into the jar, immediately cover it with the pie plate and observe. The hot water will add moisture to the jar as the water vapor rises, cools as it nears the ice and condenses. Some of the students may also see precipitation in the activity.
Divide the class into teams. Give each team a glass beaker marked in centimeters, a metal jar lid large enough to fit the opening of the beaker, ice cubes, black paper and a flashlight. They will make a cloud by filling the beakers with hot water, letting it sit for four minutes and pouring out all but 2.5 cm of the water. Drop a lit match into each beaker. Have the teams put the lid on the beaker, place ice cubes on top, hold the black paper behind the beaker and turn on the flashlight. Water vapor will cool and condense around tiny particles of smoke to make a cloud.
To see how precipitation occurs, use a large pot to boil water. When steam rises from the pot, hold a smaller pot filled with cold water and ice over the larger pot. Water droplets “rain” from the bottom of the smaller pan when they become heavy enough fall. The water cycle is complete.
Your students can make a model water cycle using a glass jar, three small plants, a plastic water bottle cap, soil, small rocks and sand. Have them should put a 1/2-inch layer of the rocks in the bottom of the jar and add a 1/2-inch layer of sand topped with 1 inch of soil. Adjust the depth of the layers for a small or large jar. Ask them to add the plants gently and put the bottle cap, filled with water, inside. They should then put the lid on the jar and set the model where it will get some sun. Make hourly observations the first day and daily observations after that.