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(the spreading of particles toward an even distribution)

Diffusion is the net movement of particles such as atoms or molecules from areas of higher concentration to areas of lower concentration.

A Diffusion Equation is an equation describing diffusion over time. Fick's Laws include a diffusion equation describing what happens in many cases. That type of diffusion is called Fickian Diffusion, and the equation is:

J = -D ——
  • J - the Diffusive Flux, the flow of the diffusing substance as substance/time.
  • D - the diffusion coefficient of the substance.
  • C - the concentration of the substance.
  • x - measurement over a direction over which we are describing the diffusion.