Hooked on Science: Cloud in a bottle

Materials

• Isopropyl alcohol
• Bicycle pump with rubber stopper
• 1-liter clear plastic bottle

Instructions

• STEP 1: Pour enough isopropyl alcohol into the clear plastic bottle to cover the bottom. Swirl the alcohol around in the bottle.
• STEP 2: Attach the pump to the rubber stopper. Attach the stopper to the bottle.
• STEP 3: Pump the bicycle pump five times. Remove the stopper and observe. How does the cloud in the bottle compare to how clouds form on Earth?

Explanation

When the stopper is removed, the air inside expands and cools, which allows the alcohol molecules to stick together or condense, creating a cloud in the bottle.