$2)$ The Bismuth $(Bi)-$ Lead $(Pb)$ phase diagram is given below;

a$)$ What are the elements of the phases $($phase contents$)$ formed at point $"$a$"?$ What are the ratios of the phases formed relative to each other?

b$)$ What are the elements of the phases $($phase contents$)$ formed at point $"$b$"?$ What are the ratios of the phases formed relative to each other?

c$)$ Draw the shape of the grains formed at point $"$b$".$ What phases constitute the grains?? What are the proportions of each grain type formed at this stage?

d$)$ What is the maximum solubility of Bi inside $$ and $$ phases? Also write the temperatures of the $$ and $$ phases where the maximum solubili $-$of Bi element is seen.