Chapter 18, Problem 1E

Interpretation Introduction

Interpretation:

The following statement should be explained.

“Though the earth was formed by the same interstellar material as the sun, there is a little hydrogen is present in the earth's atmosphere”

Concept Introduction:

The radiation and matter which is present in the space between the systems of star in a galaxy is known as Interstellar medium. This medium consists of 99% interstellar gas such as hydrogen and helium.

Answer to Problem 1E

The Earth’s gravity is not so strong to hold the lightest element that is hydrogen in the atmosphere efficiently. Thus, less amount of hydrogen is present in Earth’s surface.

Explanation of Solution

The hydrogen gas exists as dihydrogen with molecular formula ${\mathrm{H}}_2$ . It is a vital element which is needed for the existence of life. It is very important for the existence of humans as it is one of the component of water ( ${\text{H}}_{\text{2}}\text{O}$ ).

The composition of hydrogen is less in Earth’s surface that is 55 ppm. When earth was formed, large amount of hydrogen was present in the Earth’s surface but due to the heat and solar winds, its layer got depleted from the atmosphere resulting in less amount of hydrogen in Earth’s surface.

According to the periodic table, hydrogen is lightest element (hydrogen atom contains one proton and one electron); therefore, it is not likely for the earth gravity to hold it in atmosphere efficiently.