Water Cycle in a Jar

Create a mini-environment to see how water moves from the earth to the atmosphere and back again. You will observe evaporation, condensation, and precipitation in action!

Tools

• marker (1)
• ruler (1)

Materials

• glass jars (same size, 2)
• jar lid or aluminum foil (1 piece)
• blue food coloring (5-10 drops)
• water (approx. 4 cups)

Safety

• Protect work surface. Materials may stain clothing.
• Adult supervision required for children under 8.

Steps

1. Ask an adult to help fill both glass jars with equal amounts of water to ensure a fair test.
2. Add a few drops of blue food coloring to each jar and stir gently.
3. Use the marker to mark the starting water level on the outside of both jars.
4. Place the lid or a piece of aluminum foil tightly over the top of one jar, leaving the other jar open.
5. Place both jars side-by-side on a sunny windowsill.
6. Observe the jars daily and use the ruler to measure any changes in the water levels.
7. Compare the two jars: notice how the open jar loses water to evaporation, while the covered jar creates droplets (condensation) that fall back down (precipitation).