Chapter 12, Problem 12.102AP

(a)

Interpretation Introduction

Interpretation: The ionic radii of ${\text{Al}}^{\text{3+}}$ and ${\text{P}}^{\text{3-}}$ being consistent with the size requirements of the ions in a sphalerite crystal structure if aluminum phosphide is an ionic compound and the atomic radii of $\text{Al}$ and $\text{P}$ being consistent with the size requirements of atoms in a sphalerite crystal structure if aluminum phosphide is a covalent compound is to be validated.

Concept introduction: Aluminum phosphide (AlP) is used in making light-emitting diodes (LEDs). Ionic crystals consist of two or more different type of ions that usually have different sizes.

The radius ratio is calculated by the formula,

$\text{Radius}\text{ratio}=\frac{\text{Radius}\text{of}\text{cation}}{\text{Radius}\text{of}\text{anion}}$

To validate: The ionic radii of ${\text{Al}}^{\text{3+}}$ and ${\text{P}}^{\text{3-}}$ being consistent with the size requirements of the ions in a sphalerite crystal structure if aluminum phosphide is an ionic compound.

(b)

Interpretation Introduction

To validate: The atomic radii of $\text{Al}$ and $\text{P}$ being consistent with the size requirements of atoms in a sphalerite crystal structure if aluminum phosphide is a covalent compound.