Water Cycle in a Bag

Visually demonstrate how the water cycle works using a sealed bag to show evaporation, condensation, and precipitation.

What you need

• A ziplock plastic bag (transparent)
• Blue food coloring (optional)
• Water
• A permanent marker
• Sticky tape
• A sunny window

How it works

As the sun heats the water, evaporation occurs inside the bag. The vapor cools and sticks to the top of the bag as condensation. When enough droplets form, they roll down like precipitation (rain). This is a mini model of the real water cycle.