States of matter
Make a water cycle in a bag
Can you make rain happen on a window?
Watch first
See how the same stuff can be a solid, a liquid or a gas.
What you need
Tick each one as you find it — 0 of 5 ready.
Plan the fair test
- Change: How warm the window is
- Measure: How much water collects at the top of the bag
- Keep the same: Same bag, same amount of water, same amount of time
Objectives this evidences
- Identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature
Do it, one step at a time
Step 1 of 4
- Step 1. Pour a few centimetres of warm water into the bag and add a drop of colouring.
- Step 2. Draw a sun and a cloud on the bag with a marker, seal it shut, and tape it to a sunny window.
- Step 3. Look at it after an hour, then again later in the day, and draw what you can see.
- Step 4. Now try a second bag taped to a cool, shaded window and compare them.
What should happen
Water evaporates, condenses in drops at the top of the bag, then runs back down — evaporation, condensation and precipitation in miniature. The warm window does it faster.
Think about: No water left the bag. Where does the water in real rain come from?
Write up your result
A sentence or two is enough to save it.
The lessons behind this practical
Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.
Now the quiz for this topic
Questions come from the lessons behind this practical, so nothing is asked that has not been taught.
Quiz
States of matter quiz
4 questions from the lessons in this stage. No timer, and you can try again as many times as you like.