Chapter 4, Problem 4.43SP

(a)

Interpretation Introduction

Interpretation:

Using the given elements $\text{Si,Cl}$ and $\text{Ca}$, formula for an ionic compound has to be given.

Concept introduction:

Ionic compound:

A compound which consist of anions and cations held together by ionic bond (electrical attraction of opposite charges).

Ionic character increases as increasing difference in electronegativity.

(b)

Interpretation Introduction

Interpretation:

Using the given elements $\text{Si,Cl}$ and $\text{Ca}$,the molecular compound with covalent bond that obeys octet rule and do not have any formal charge has to be predicted.

Concept introduction:

Molecular compound;

Molecular compound is formed by combining non-metals by covalent bonds in which each bond share pair of electrons.

Octet rule:

Octet rule states that atoms of main group elements have a tendency to react so that achieve a noble gas configuration in s and p subshell (eight electrons).

Formal charge:

The formula used to find the formal charge is,

$\text{Formal charge = }\left(\begin{array}{l}\text{Number of valence}\\ \text{ electron in free atom}\end{array}\right)\text{ - }\frac{1}{2}\left(\begin{array}{l}\text{Number of }\\ \text{bonding }\\ \text{electrons}\end{array}\right)-\left(\begin{array}{l}\text{Number of }\\ \text{non-bonding electrons}\end{array}\right)$