1. Activity #1 1.Spray perfume at the back of the room and then move to the front of the room. 2.Observe for 2-3 minutes. Activity #2 1.Fill a cup with water. Gently touch the surface of the water and taste the water. 2.Drop a sugar cube into the cup of water. 3.Taste the water after 10 minutes.

2. DIFFUSION

3. Learning Objectives At the end of the lesson, you will be able to Define diffusion and explain its phenomenon Describe an example of diffusion in plants Describe an example of diffusion in animals

4. What happens during diffusion? http://www.youtube.com/watch?v=WxfIDpset2I

5. Point A Point B

6. NET

7. BA Distance Concentration of particles Particles diffuse down a concentration gradient Direction of particle movement (net) Concentration gradient: The difference in concentration between two regions

8. Point APoint B The concentration of particles at point A and B have become the same. There is no net movement of particles.no net movement After some time… what will the concentration of particles at A and B look like?

10. A small beaker of distilled water was placed on a bench. Using a pipette, a drop of iodine was placed at the bottom of the beaker. Explain why the water in the beaker was uniformly yellow after two hours. There is a net movement of iodine molecules from where they are in a higher concentration which is at the bottom of the beaker to where they are in lower concentration which is the rest of the liquid in the beaker. Therefore, the iodine molecules spread out evenly after two hours. After 2 hours

11. A small beaker of distilled water was placed on a bench. Using a pipette, a drop of iodine was placed at the bottom of the beaker. The beaker was uniformly yellow after two hours. How can we increase the rate of diffusion in this case? By heating the beaker of water

12. Example of diffusion in animals: Diffusion of oxygen from lungs to red blood cells. Diffusion of carbon dioxide from blood to lungs. Example of diffusion in plants: Diffusion of carbon dioxide into the leaves of plants.

13. Diffusion of oxygen from lungs to red blood cells

14. Diffusion of carbon dioxide into the leaves of plants

15. DIFFUSION What have we learnt in today’s lesson? Definition: The net movement of particles down a concentration gradient Atoms, ions or molecules The difference in concentration between two regions

16. Activity #1 1.Spray perfume at the back of the room and then move to the front of the room. 2.Observe for 2-3 minutes. Activity #2 1.Fill a cup with water. Gently touch the surface of the water and taste the water. 2.Drop a sugar cube into the cup of water. 3.Taste the water after 10 minutes. Explain what happened in…

17. Preparation for next lesson Potato experiment! 1.Cut out a strip of potato 2.Measure its length and breadth 3.Soak it in tap water for 5 mins 4.Measure its length and breadth again 5.Soak it in saltish water for 5 mins 6.Measure its length and breadth again 7.Share findings with class! Don’t be a !!!!