In order for condensation to take place, water vapor must come in contact with a surface that is colder than the surrounding area. The glass of lemonade provided the cold surface in the above story. What happened in Dewey’s adventure to change him back to liquid water? The upper atmosphere if full of fine dust particles. Dust and water combine to form rain drops. As the temperature drops, the newly formed raindrops become heavier and fall from the sky.

Condensation on cups activity

Materials:

• Two clear plastic cups
• Ice cubes
• Water

Procedure:

1. Fill one cup half full with room temperature water. Fill the second cup half full with ice cubes and water.
2. Let the cups sit side by side for about ten minutes. What do you notice on the outside of the cups? The water on the outside of the icy cup came from the water vapor in the air. If the air in your room is too dry, you may not get any water condensation. If this happens, try fogging up the cup with your breath. You know, just like you do on a window when it's cold outside. Do the same to both cups.
3. Is there a difference between the results of the room temperature cup and the ice water cup? Explain why the results were different.

Water Bottle Experiment

Materials:

• One clear plastic cup with a lid or a clean empty water or soda bottle with a
  screw-top cap.
• Measuring cup
• Water

Procedure:

1. Carefully pour about 50 ml. of water into the container and close the lid.
2. Use a marker to show the water level on the bottle.
3. Set the closed container in a sunny window sill for a day and leave it overnight.
4. What do you observe? What made the water vapor condense on the inside of the container. Explain your answer.