Chapter 19.8, Problem 19.6CP

(a)

Interpretation Introduction

Interpretation:

The formula and charge of the anion of given represent silicate structure has to be drawn.

Concept introduction:

A ${\text{SiO}}_{\text{4}}$ structural unit, with an $\text{Si}$ atom at the center of the tetrahedron and an $\text{O}$ atom at each corner.  Each terminal (unshared) $\text{O}$ atom needs one electron to complete its octet and therefore has a charge of -1.  Each bridging (shared) $\text{O}$ atom completes its octet by forming bonds to two $\text{Si}$ atoms and is therefore electrically neutral.

(b)

Interpretation Introduction

Interpretation:

The formula and charge of the anion of given represent silicate structure has to be drawn.

Concept introduction:

Each tetrahedron represents a ${\text{SiO}}_{\text{4}}$ structural unit, with an $\text{Si}$ atom at the center of the tetrahedron and an $\text{O}$ atom at each corner.  Each terminal (unshared) $\text{O}$ atom needs one electron to complete its octet and therefore has a charge of -1.  Each bridging (shared) $\text{O}$ atom completes its octet by forming bonds to two $\text{Si}$ atoms and is therefore electrically neutral.