Chapter 1, Problem 1.19QP

(a)

Interpretation Introduction

Interpretation: From the given list, the species that are elements are to be stated.

Concept introduction: When the atoms belonging to different elements are chemically combined in a fixed ratio then it leads to the formation of a compound. But when the atoms of same type are combined together then it leads to the formation of an element.

To determine: If ${\text{Cl}}_2$ is an element or not.

(b)

Interpretation Introduction

To determine: If ${\text{H}}_2\text{O}$ is an element or not.

(c)

Interpretation Introduction

To determine: If $\text{HCl}$ is an element or not.

(d)

Interpretation Introduction

To determine: If $\text{NaCl}$ is an element or not.