Chapter 13.1, Problem 1BYL

To determine

The definition of atmosphere including its average composition.

Answer to Problem 1BYL

A relatively thin layer of gas that surrounds surface of the Earth is termed as atmosphere. The dominant gases in the atmosphere are nitrogen (78.084%), oxygen (20.946%), and argon (0.934%).

Explanation of Solution

The atmosphere is the relatively thin gas layer that surrounds the surface of the Earth. It protects the Earth from the harmful high-energy radiations that are emitted from the space. It contains oxygen, water vapour, and other gases on which all forms of life depend.

The atmosphere is not completely homogeneous in the vertical, horizontal, or temporal composition. The two dominant gases present in the atmosphere are nitrogen and oxygen, and they constitute 78% and 21%, respectively. Argon is also present in a minor amount, and it is about 0.934 percent. In addition, variable amounts of water vapor are also present in the atmosphere along with carbon dioxide, methane, nitrous oxide, and ozone.

The atmosphere is characterized by the presence of different types of solids and liquids known as aerosols that includes dust, industrial pollutants, and tiny drops of liquid that are emitted from volcanic eruptions.