Diffusion is the result of concentration gradient which refers to
Change of concentration with respect to time
Change of concentration with respect to space
change of concentration with respect to temprature
Change of concentration with respect to gravity
As we have learned
Diffusion -
Movement of all substances from the area of their higher free energy to the area of their lower free energy along the concentration gradient.
- wherein
Neutral solutes move across the membranes by diffusion.
Net direction of diffusion of particles depends on its concentration in a particular region or space