Which of these terms, Diffusion Coefficient, Steady-stateDiffusion, Non Steady-state Diffusion, Diffusion Flux best describes the following sentences?
a) The quantity of mass diffusing perpendicular to a unit cross-sectional area of material per unit time
b) The constant of proportionality that represents the rate of atomic diffusion
c) The diffusion condition for which there is no net accumulation or depletion of diffusing species
d) The diffusion condition for which there is some net accumulation or depletion of diffusing species