1. SIMPLE DIFFUSION AND OSMOSIS

2. SIMPLE DIFFUSION

3. WHAT IS DIFFUSION
Diffusion is the movement of molecules or particles from a region of high concentration to a region of low concentration OR
We can say molecules or particles move from an area where there is more particles or molecules to an area where there is less

5. HOW DIFFUSION OCCCURS
Molecules and particles are in constant random motion.
This is due to the energy that they posses; this is known as KINETIC ENERGY
Solids are closely packed so they vibrate and contain little kinetic energy
Liquids move around to occupy the space of the container and contain more kinetic energy so they move more
Gases move about freely in space and contains lots of kinetic energy so they can move faster

7. HOW DIFFUSION OCCURS
When molecules or particles are mixed the kinetic energy they posses allows them to move about until they are evenly distributed
So the amount of kinetic energy a molecule posses will determine how fast it diffuses
However there are other factors that will affect the rate of diffusion or how fast diffusion occurs

8. MORE ON DIFFUSION Diffusion can occur with:
liquids and solids (water and dye)
different liquids (water and ink)
different gases (gases in the air)
When particles or molecules are evenly mixed no more changes occur
We can compare the rate of diffusion of different substances

9. MORE ON DIFFUSION
Diffusion occurs everywhere but can be demonstrated in the lab with different chemicals
The rate of diffusion is affected by the size of the molecules and temperature
The larger the molecules the slower it will move therefore smaller molecules will move faster and diffuse faster
At higher temperatures particles or molecules posses more kinetic energy and therefore the higher the temperature the faster the rate of diffusion

10. EXAMPLES OF DIFFUSION When you smell a flower
When someone sprays perfume on one side of the room and the person on the other side smells it
When we add dye to water in celebrating Phagwa
When making cool aid

11. OSMOSIS
This is the movement of water particles from a region of high water concentration to a region of low water concentration through a selectively permeable membrane.

12. WHAT DO YOU OBSERVE IN THE PICTURE BELOW
PINK = WATER PURPLE = SUGAR

13. Water molecules move across the selectively permeable membrane
The volume in the second half increases but the concentration of the water molecules is even
Water molecules are smaller
The selectively permeable membrane acts as a barrier for larger molecules

15. IMPORTANCE OF OSMOSIS Cells get water via osmosis
Osmosis occurs in all living cells and helps to regulate the amount of water in the cells
Water is very important for all chemical reactions occurring in the cell.
If a cell is placed in too much water it can burst
If a cell is placed in a concentrated solution it can shrink and become dehydrated.
Plant cells have a cell wall that prevents the cells from bursting.

17. COMPARING BOTH DIFFUSION AND OSMOSIS
Diffusion and Osmosis is the process of moving particles from a region of high concentration to a region of low concentration
Diffusion occurs with any particle
Osmosis occurs ONLY with water molecules across a selectively permeable membrane
Both processes are important to the human body and living things
Both can be applied to many processes in science and everyday life.