Section E: Solidification (10 pts] a) [3 pts) Calculate the critical volume v* of a spherical Ni nucleus if nucleation is homogeneous, assuming a supercooling value of 25C. Assume that AH, = 9.65 x 108 J/m3, y = 0.126J/m2, and Im = 962C. b) [3 pts] Silver has an FCC crystal structure with a = 0.409 nm. Calculate the number of atoms which would need to cluster together in order to form a nucleus with the volume calculated in part a. c) [4 pts) How many atoms would need to cluster together if the supercooling value was increased to 227C