What are some examples of diffusion?
Diffusion takes place constantly in our bodies and is vital to cell functioning. Cell walls are selectively permeable, meaning that certain substances can pass through them, but others cannot. Diffusion allows certain materials to move into and out of cell walls, from a higher concentration to a lower concentration. For example, oxygen diffuses from the air sacs in your lungs into your blood capillaries because the concentration of oxygen is higher in the air sacs and lower in the capillary blood. Different kinds of membranes allow differing amounts of diffusion to occur. Think about a helium balloon. It starts out full of helium and floats upwards, but over a period of a day or two it loses helium until it is no longer lighter than air and cannot float any more. Why does this happen? The balloon allows the helium atoms to pass through it into the atmosphere. Helium…
