For an FCC single crystal, would you expect the surface energy for a (100) plane to be greater or less than that for a (111) plane? (Note: You may want to consult the solution to Problem 3.58 at the end of Chapter 3.)

Derive planar density expressions for FCC (100) and (111) planes in terms of the atomic radius
Compute and compare planar density values for these same two planes for aluminum (Al).

In a unit cell of fcc structure, indicate the position of one of the tetrahedral interstitial sites by plotting the corresponding tetrahedron. do the same for one of the octahedral interstitial sites (in a separate fcc unit cell). mark the positions of all the tetrahedral and octahedral interstitial sites in the unit cells. how many equivalent tetrahedral sites and how many equivalent octahedral sites are contained in a fcc unit cell, respectively. what is the coordination number for a tetrahedral site and what is the coordination number for an octahedral site?