(a) Self-diffusion involves the motion of atoms that are all of the same type; therefore, it is not subject to observation by compositional changes, as with interdiffusion. Suggest one way in which self-diffusion may be monitored. (b) Explain why interstitial diffusion of small atoms is faster than vacancy diffusion. C) Draw a crystal structure plane with edge dislocation. Indicate the location in the vicinity of an edge dislocation where an interstitial impurity atom would likely be situated. Briefly explain your answer in terms of lattice strains and also hypothesize how it would influence the climb of the dislocation at elevated temperatures