Create a miniature version of Earth's water cycle inside a glass jar. You will observe evaporation, condensation, and precipitation in action to see how water is recycled in nature.

Tools

• ruler
• marker

Materials

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

Safety

• Adult supervision required when handling glass jars to prevent breakage.
• Adult assistance needed to fill jars with water.
• Adult supervision required for sharp objects.
• Protect work surface. Materials may stain clothing.
• Adult supervision required for children under 8.

Steps

1. Ask an adult to help you fill both glass jars with equal amounts of water.
2. Add a few drops of blue food coloring to each jar and stir gently to make the water visible.
3. Use the marker to label one jar as 'Open' and the other as 'Covered'.
4. Place the lid (or a piece of aluminum foil) tightly over the 'Covered' jar to seal it.
5. Place both jars side-by-side on a sunny windowsill where they will receive direct sunlight.
6. Observe the jars daily. Use the ruler to measure the water level in both jars and mark the changes with your marker.
7. Compare the two jars: notice how the water level in the open jar drops (evaporation) while the covered jar maintains its level.
8. Look closely at the top of the covered jar to see tiny water droplets forming (condensation) and eventually dripping back down (precipitation).