Chapter 14.4, Problem 46LC

Interpretation Introduction

Interpretation: The similarity and differences between the two tables showing the composition of dry air and elements in the atmosphere need to be explained.

Concept Introduction: Air is composed of different gases. Here, the major component is nitrogen and oxygen gas. There are different elements also present in the atmosphere. Air is a part of the atmosphere here, the atmosphere includes air, water earth, and other surroundings.

Explanation of Solution

The following table shows the composition of dry air:

Component	Volume (%)	Partial pressure (kPa)
Nitrogen	78.08	79.11
Oxygen	20.95	21.22
Carbon dioxide	0.04	0.04
Argon and others	0.93	0.95
Total	100.00	101.32

The table in which elements in the atmosphere us mentioned list the data on the composition of air. It is represented as follows:

Element	Parts per million
Nitrogen	780,900
Oxygen	209,500
Argon	9300
Neon	18
Helium	5.2
Krypton	1.14
Hydrogen	0.5
Xenon	0.086
Radon	Traces

The similarity between the two tables is that both shows the composition of nitrogen, oxygen, and argon in the atmosphere. Here, nitrogen and oxygen are in elemental form as gases. Since carbon dioxide is not an element (it is a compound), its composition is not shown in the table showing elements in the atmosphere. Also, the exact composition of Argon and other neon gases is mentioned in the atmosphere in the second table; however, in the first table, the combined composition of argon and other gases is mentioned. In the second table, the composition is shown in terms of concentration that is parts per million but in the first table, the composition is in terms of volume percentage and partial pressure.