At high temperatures, diffusion at these structures becomes more likely to involve long and rebound jumps rather than nearest-neighbor jumps. These structures are called "vicinal" if they are slightly misoriented from symmetry. Atoms in these structures are classified as terrace, ledge, or kink. (15[1])Atoms located in these structures rearrange to form (*) dangling bonds, increasing their strain but decreasing their energy. Excess atoms at these structures diffuse in a mechanism called hopping and are called adatoms. If the free energy of these structures is higher than that of the bulk, sublimation will favorably occur. The free energy per unit area of these structures can be calculated from the contact angle of a liquid droplet on top of them. Reactivity of these structures is decreased in passivation. For 10 points, name this part of a solid material whose area is maximized for a sphere. ■END■