material chemistry

(a) There are 3 stages involved in the solidification of pure metal liquid. Explain this process with an illustration. (5 marks) (b) Distinguish with the aid of a diagram between the formation of the Schottky defect and Frenkel defect in an ionic solid of Na2O. (6 marks) (c) The number of grains for Cu and Zn is shown in Table 1. (i) Justify whether Cu or Zn has a higher ASTM number with calculation. (5 marks) (ii) State whether Cu or Zn has a higher grain size. (1 mark)