Reproduction, plant gas exchange and particles on the move
The hot-and-cold diffusion race
Do particles spread out faster in warm water or cold water?
Watch first
An English teaching video on this topic from Archie Science Show. Watch it, then scroll down for the lesson.
What you need
Tick each one as you find it — 0 of 5 ready.
Stay safe: Use warm tap water, never boiling. Wipe up spills straight away.
Plan the fair test
- Change: The temperature of the water
- Measure: Time taken for the colour to spread evenly, in seconds
- Keep the same: Volume of water, size of the drop, no stirring, same glass shape
Objectives this evidences
- Understand diffusion in terms of the particle model, and the concepts of solutions, solvents, solutes and solubility
Do it, one step at a time
Step 1 of 4
- Step 1. Fill one glass with 200 ml of cold water and the other with 200 ml of warm water. Let both stand for a minute so the water is still.
- Step 2. At the same moment, add exactly one drop of colouring to the centre of each glass. Do not stir.
- Step 3. Time how long each glass takes to become one even colour, checking every thirty seconds.
- Step 4. Repeat once more to check your result, then draw the two glasses at one minute, two minutes and five minutes.
What should happen
Colour spreads faster in the warm glass: warm particles have more energy, so diffusion is quicker.
Think about: Where does the colour 'go'? Use the particle model to explain why the colour never gathers back into a drop.
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
Reproduction, plant gas exchange and particles on the move quiz
6 questions from the lessons in this stage. No timer, and you can try again as many times as you like.