☯ Concept Cartoons ☯
1 Chemistry Solids, Liquids and Gases 2 - When does water vapour condense?
Have you talked about your ideas? Do you agree with any of the characters or do you think something different? Do you all have the same ideas? Here are some ways of finding out more. Talk about where and when you see condensation. What have you noticed about the temperature or anything else that might help to explain where the condensation comes from? Talk about when and why condensation happens in a bathroom. Talk about how you can make condensation happen. Take a can or bottle out of a fridge and see what you notice. What is the connection between condensation and rain or snow?
Here’s what a scientist might say. Did you find any evidence to support or justify these ideas? Are there any questions that you still need to answer? Condensing is when a gas turns into a liquid. Gases change state as they cool, so when water vapour (water in the form of a gas) hits a cold surface it changes into liquid water and makes tiny droplets on the cold surface. This covering of water droplets is called condensation. It happens on windows and car windscreens in winter because the glass is cold. It can also happen at a higher temperature when the air has a large amount of water vapour in it, such as in a bathroom, at a swimming pool or in a rain forest. If the surface is below 0°C, the water vapour can change directly into ice without changing into liquid water first. This is a special form of condensing called deposition. Create a poster to explain how it is possible to get condensation on the windows of an air-conditioned car on a hot day.