Changes

==Introduction==

==Introduction==

If gases or liquids are unevenly distributed between two areas.  One area having a higher concentration than the other then the differance between those two areas is termed the '''concentration gradient'''.  The equality is then corrected by the movement of the molecules down this so called gradient from the region of high concentration to that of low.  This process is '''passive''' as the molecules do not have to be forced to do this and it is reffered to as '''diffusion'''.

Gases or liquids can be unevenly distributed between two areas.  If one area has a higher concentration than the other then the differance between these two areas is termed the '''concentration gradient'''.  The equality is then corrected by the movement of the molecules down this so called gradient from the region of high concentration to that of low.  This process is '''passive''' as the molecules do not have to be forced to do this and it is reffered to as '''diffusion'''.