Please show each step of your solution!

2. A plate is made of material A with a thickness of 5mm that contain 5%wt of material B. The board is placed on a surface which prevents diffusion and hence the diffusion is only possible from the upper surface of the plate. Assume that the concentration of B on the upper surface is zero (and constant) and that there is no diffusion from the sides of the plate. Given: D=10(cm/sec] a) Find an analytic expression for C(z,t) of Bin A after1 month. b) Draw (schematically) the concentration profile C(z) after 1 month. c) What is the concentration of B at a distance of 1mm from the upper surface of the plate after 30 days (exactly)? N N Sample (plate) Diffusion barrier