Let’s Learn About the Water Cycle! 3 Simple Water Cycle Experiments
April is the perfect month to teach students about the water cycle and what makes rain. Here are 3 of my favorite water cycle experiments. These science experiments are simple to set up and use common household items.
First, introduce your students to the water cycle and the following terms: evaporation, condensation, precipitation, collection.
The earth has a limited amount of water. This water keeps going around and around in what we call the water cycle. When the sun heats the water in the lakes, streams, oceans, etc. some of it turns to a gas (water vapor). This is called evaporation. This invisible water vapor is light and rises into the air.
When the water vapor hits the cold air high up in the atmosphere it turns back to water droplets and collects in clouds. This is called condensation.
When too many water droplets form in a cloud, the cloud gets heavy and the water falls back to the earth in the form of rain, hail, sleet, or snow. This is called precipitation.
When the water falls back to the earth, it may fall back in the streams, lakes, ocean, etc. or it may fall on the land. This is called collection. When it falls on the land, it either soaks into the earth for plants to drink or runs over the soil and back into the streams, lakes, oceans, etc. and the cycle begins all over again.
These simple science experiments will help demonstrate the water cycle or parts of the water cycle.
mug or small cup
string or large rubber band
Place the mug or small cup in the center of the bowl. Fill the bowl with water about 2/3 of the way up the cup (do not put water inside the cup).
Cover the bowl with saran wrap and either tie it with string or place a large rubber band around it to secure the plastic wrap.
Place it outside in a sunny area for a few hours.
After several hours, allow students to observe the bowl. The plastic wrap will have condensation and some of the condensation will have dripped or fallen into the cup/mug.
This experiment demonstrates the heat of the sun turning the water in the bowl to vapor (evaporation). The vapor turning back to water droplets on the saran wrap (condensation), drops getting too heavy and falling back down (precipitation) to the water in the bowl or in the mug which represents mountains or land (collection).
blue food coloring (optional)
If desired, draw water, a cloud, and a sun on the Ziploc baggie with a marker.
Add a small amount of water to the baggie without getting the sides wet.
Add a few drops of blue food coloring to the water (optional).
Hang on a sunny window for several hours.
After several hours or when heavy condensation appears on the bag, remove the bag and allow students to observe. Tap the bag, if necessary, to make the water droplets fall.
This experiment allows students to observe the water from the bag evaporating, condensing, falling like precipitation, and collecting again at the bottom. Notice that the water does not stay blue once it evaporates. This is because the food coloring is heavier than the water vapor and thus stays down, much like the salt from the ocean water.
straw or eye dropper
blue food coloring
Place approximately 3 tablespoons of water in the small glass and add about 10 drops of blue food coloring.
Fill the medium glass with water. Add 1-3 inches of shaving cream to the top. The more shaving cream used the longer the experiment will last.
Add the colored water to the shaving cream drop by drop using an eye dropper or by dipping the straw in the colored water, placing your finger over the end, holding it over the shaving cream, and lifting your finger enough to allow drops of colored water to drip onto the shaving cream.
Continue dropping the water onto the shaving cream until you observe it getting too heavy and “rain” starting to come out below. Depending on the amount of shaving cream used, this could take anywhere from 40-100 drops.
This experiment demonstrates what happens in the clouds during the water cycle. When a cloud accumulates too many water droplets they fall in the form of precipitation. In the experiment, after a certain point the shaving cream can no longer absorb the water drops and gravity pulls them down into the water.