Describe the process of diffusion
Diffusion is the random movements of molecules from the region of high concentration to a region of low concentration. Form the diagram on the sheet, the particles are highly concentrated on the left jar at one side, later the particles will constantly move and colliding with each other making them to spread in the jar. This will result to an equal amount of particles being spread in the jar.
Intermediate level task changing the rate of diffusion
Diffusion is affected depending on the temperature, shape and size of the molecules, surface area and the pathway of diffusion.
The higher the temperature, the faster the rate of diffusion, this is because the kinetic energy is high and this makes the molecules to collide with each other and therefore koe faster.Small molecules also make the diffusion to happen quicker, diffusion take longer with large particles because they take a long time for them to absorb heat from the surrounding.
The rate of diffusion can also be changed by increasing or decreasing the diffusion pathway. The further the molecule has to travel,the longer it take for diffusion to happen but when the diffusion distance is shorter,the rate of diffusion will faster.Concentration gradient also affect the rate of diffusion.The greater the concentration gradient ,the faster the rate of diffusion.Surface area also affect the rate of diffusion,the greater the surface area,the faster the rate of diffusion.
Advanced molecules task:Application of diffusion
Alveoli in human lungs
Alveoli in the lungs are made up of allveolae epithelium.They are mostly in the lungs because they are used for gas exchange,and therefore they have a large surface area to exchange the gases..In the alveoli oxygen diffuse out of the lungs through the alveolar epithelium of the blood while carbon dioxide diffuses into the alveoli from the blood and is breathed out.Because the alveolar epithelium is thick,this means that the diffusion distance is short...