How are ice and water the same and different?
3. Discuss condensation
One goal of this brief conversation is for students to pay attention to another instance of condensation. Note that the amount of condensation that forms on the ice-filled plastic cups will depend on the amount of water vapor in the classroom air.
Do you notice any condensation forming on the outside of your cups holding the ice? Where?
- Next to the ice cubes or ice water, on the coolest parts of the cup just as condensation formed on the coolest surfaces of the 2-bottle system.
- Where are the droplets coming from? Why do you think they are forming?
- Do you think that water vapor in the air and water forming on the outside of the cold cup are the same kind of matter?
Note: A common misconception is that the condensation is water that leaks through the plastic. If someone suggests this, show the class the bottle holding room temperature water and point out that no water is leaking through that plastic.