1. (a) Assume for the solidification of nickel (Problem 10.4) that nucleation is homogeneous, and the number of stable nuclei is 106 nuclei per cubic meter. Calculate the critical radius and the number of stable nuclei that exist at the following degrees of super- cooling: 200 K and 300 K.
(b) What is significant about the magnitudes of these critical radii and the numbers of sta- ble nuclei?
2. For some transformation having kinetics that obey the Avrami equation (Equation 10.17), the parameter n is known to have a value of 1.5. If, after 125 s, the reaction is 25% com- plete, how long (total time) will it take the transformation to go to 90% completion?