Question

ion ionic radius
cs⁺ 167 pm
f⁻ 133 pm
based on the data in the table, which of the following diagrams best depicts the structure of the ionic solid csf?
choose 1 answer:

Explanation:

Step1: Analyze ion - size ratio

The ionic radius of $Cs^+$ is 167 pm and of $F^-$ is 133 pm. The cation ($Cs^+$) is larger than the anion ($F^-$). In an ionic solid structure, larger cations tend to be surrounded by larger numbers of anions and the relative sizes of ions determine the coordination number and the overall structure.

Step2: Evaluate diagrams

In an ionic compound like CsF, the larger $Cs^+$ ions and smaller $F^-$ ions will be arranged such that the anions ($F^-$) surround the cations ($Cs^+$). Diagram A has ions of similar size, which is incorrect. Diagram B has smaller cations surrounded by larger anions in a way that does not match the size - relationship of $Cs^+$ and $F^-$. Diagram C correctly shows the larger $Cs^+$ ions (represented by the larger circles) and smaller $F^-$ ions (represented by the smaller circles) with the anions surrounding the cations in an ionic - lattice structure. Diagram D has incorrect ion - size representation as well.

Answer:

C