1. Equipment Gas pressure and diffusion reading handout
Differentiated diffusion worksheets
Potassium permanganate experiment – Could be a demo to save time.

2. Task: Put the pictures and statements in order to describe diffusion.1. 2. 3. 4.
Task: Put the pictures and statements in order to describe diffusion.
HARD - pink
The particles are now nearly fully mixed up and diffused.
The particles are fully diffused as they are all mixed up.
The particles are separate when first put together.
The particles slowly start to mix due to their random movement.

3. Task: Put the pictures and statements in order to describe diffusion. 1. 2.
The particles slowly start to mix due to their random movement. 3. 4.
The particles are now nearly fully mixed up and diffused.
The particles are fully diffused as they are all mixed up.
The particles are separate when first put together.
MEDIUM - yellow

4. Task: Put the pictures and statements in order to describe diffusion. 1. 2.
The particles slowly start to mix due to their random movement. 3. 4.
The particles are now nearly fully mixed up and diffused.
The particles are fully diffused as they are all mixed up.
The particles are separate when first put together.
EASY - green

6. Retrieval practice
1) What are the missing gaps 1, 2, 3, 4 2) List some of the properties of gases 3) Describe the change of state ‘evaporation’ in terms of closeness, arrangement and motion of particles 4) What does the term sublimation mean? 1 2 3 4

7. What is the difference between these two particles?
TWWL: about diffusion SO THAT I CAN…
State the meaning of gas pressure
Explain diffusion using the particle model
Describe differences in diffusion of gases and liquids
Investigate how temperature effects how quickly diffusion happens
What is the difference between these two particles?
Energy and direction

8. What’s going on in this video?
Gas pressure
What’s going on in this video?

9. Read ‘pressure in gases’ from your hand-out
As a class or independantly

10. Gas pressure APPLY State the meaning of gas pressure?
What happens when you put a balloon animal in liquid nitrogen (very cold). Why?
Why is it that balloons can burst on a hot day?

11. States and diffusion
gas (e.g. steam)
liquid (e.g. water)
solid (e.g. ice)
Demo the squash.
Molecules in liquids and gases are constantly moving and bumping into each other. This means that they tend to spread out. 11

12. Read ‘diffusion’ from your hand-out

13. What is diffusion?

14. What is diffusion?
the spreading out of a substance within a liquid or gas. It doesn’t require stirring!

15. Is diffusion quicker in liquids or gases?

16. Is diffusion quicker in liquids or gases?
Gases – because the particles in a gas move more quickly than in solids

17. Brownian Motion
Particles in both liquids and gases move randomly. This is called Brownian motion.
They do this because they are bombarded by the other moving particles. Larger particles can be moved by light, fast-moving molecules

18. Particles in diffusion
Task: Pick a worksheet to complete. Assess how you feel about this topic so far
Confident/Exceeding – Pink sheet
Ok/secure – Yellow sheet
A little unsure/Developing – green sheet

19. Particles in diffusion
Method
1 You will be measuring the time it takes for all the water in your beaker to go purple in colour.
2 Place 200 cm3 water from the tap into a 250 ml beaker.
3 Record the temperature of the water.
4 Select a crystal of potassium permanganate using tweezers and use the plastic straw to carefully place the crystal into the water, at the bottom of the beaker. (Do not release it from the tweezers until the straw is on the bottom of the beaker.)
5 Quickly remove the straw from the beaker.
6 Start the stopwatch.
7 Record the time it takes for the water to become purple throughout.
8 Repeat this procedure with water at different temperature (50 °C, 70 °C, 90 °C) and water cooled in an ice bath. Try to select similar sized crystals each time.

20. Diffusion practical In this practical you will:
see how temperature affects how quickly particles can diffuse in a liquid
Wear eye protection.
Take care when handling hot equipment and very hot water.
Potassium permanganate is harmful and oxidising. Avoid contact with skin.
Mop up chemical spills using a dry paper towel.
Wash your hands after the lesson.

21. Diffusion practical
Which temperature of water gave the fastest time for the purple colour to spread throughout?
2. Choose the correct word to complete this sentence: At higher temperatures diffusion happens more quickly/slowly.
3. Describe the motion of the water particles at different temperatures
Extension
Applying your knowledge of particle energies, explain why diffusion occurs more rapidly at higher temperatures.

22. What is Diffusion? move warm cooler low moving high quicker gas
Diffusion is how particles move and mix by themselves without being stirred or shaken.
Only liquids and gas particles diffuse because they are moving all the time. Gases diffuse quicker than liquids.
It happens more quickly at warm temperatures than at cooler temperatures.
The particles move from where there are a lot of them (high concentration) to where there are less of them (low concentration)
Fill in the missing words

23. Reflection How do you feel about today’s objectives?
Choose a face and write why you feel this way
(I think I can now _______ because ______________)
State the meaning of gas pressure
Explain diffusion using the particle model
Describe differences in diffusion of gases and liquids
Investigate how temperature effects how quickly diffusion happens