c) Describe the principle of thermodynamics that necessitates the formation of vacancies in a crystalline solid solution. [3 marks] [3 marks] d) Discuss the different forms in which point defects exists in metals. e) Given that the number of vacancies per cubic meter in gold at 9000C is 3.52x1024. Furthermore, the density and atornic weight for Au are 18.63g/cm and 196.9g/mol respectively. Taking k=8.62x10-5eV/atom and Avogadro's number to be 6.023x1023atoms/mol. Calculate the energy required for the formation of vacancies [4 marks] in gold at this temperature. f) Compute composition in atom percent of a 92.5 wt% silver and 7.5 wt% copper alloy. Taking atomic [4 marks] weights as 63.55g/mol and 107.87g/mol for copper and silver, respectively.