Which of the following characteristics must be present in any particulate-level model of a crystalline ionic solid that is consistent with Coulomb’s law?
a) Random placement of ions provided the overall charge is zero
b) A regular, repeating alternation of cations and anions throughout three dimensions
c) Like-charged ions occupying nearest-neighbor lattice sites to balance repulsive forces
d) Variable ion–ion distances within a single unit cell so that larger ions are farther apart