Final answer:
The question discusses the formation of a crystal lattice in ionic crystals based on the relative sizes of cations and anions and their stoichiometry which determines coordination polyhedra and fits cations into interstitial sites. option c is correct
Step-by-step explanation:
Option c is correct The question refers to how ionic crystals form a structured arrangement known as a crystal lattice. Anions and cations in a crystal lattice are surrounded by as many ions as possible of the opposite charge. The coordination polyhedron that forms around each cation is determined by the sizes of the cations and anions and the stoichiometry of the compound, leading to different types of interstitial sites such as tetrahedral or octahedral holes. The ionic radius is a measure that helps in understanding these interactions. For instance, cations are smaller than their parent atoms due to the loss of electrons and anions are larger due to the gain of electrons.
The subject of this question is Chemistry. Specifically, it relates to the coordination polyhedron formed around each cation and how the cation-anion distance and number of coordinating anions are determined.
In chemistry, this phenomenon is described by Pauling's rules, which state that the cation-anion distance is determined by the sum of their radii, and the number of anions coordinating with the cation is determined by the relative size of the cation and anion.
For example, in simple ionic structures, anions, which are usually larger than cations, form a closest-packed array. Cations occupy tetrahedral or octahedral holes between the anions based on their relative sizes.