Question

Which of the following is not a constituent of the atmosphere?
(A) Oxygen
(B) Nitrogen
(C) Carbon dioxide
(D) Manganese dioxide

Answer 1

The mixture of gases surrounding the earth and other planets. The atmosphere is divided into layers according to temperature. The atmosphere is divided into four layers – Troposphere, Stratosphere, mesosphere, thermosphere.

Complete step by step answer:
The atmosphere is made up of different gasses that are necessary for different activities that occur in nature like photosynthesis-Plants need carbon dioxide and water to make food and carbon dioxide is obtained from the atmosphere. And living organisms depend on plants for their food.
In the atmosphere nitrogen is present in abundant amounts about $78\%$ and oxygen, carbon dioxide is also present in the atmosphere. Without gases living things cannot survive in earth 's atmosphere.

Hence, option D is the correct option. Manganese dioxide is not a constituent of the atmosphere.

Additional information:
In the atmosphere mesosphere is a layer that extends from about $50Km$ above the stratosphere and mesosphere is the coldest area of the earth atmosphere.Troposphere is the layer where we live in the atmosphere.Stratosphere extend from the top of the troposphere surface of the bottom of the mesosphere layer. The Stratosphere contains an ozone layer. Ozone layer is a thin part of the atmosphere that protects us from the harmful ultraviolet radiation coming from the sun. Ozone layers absorb harmful ultraviolet radiation that comes from the sun.Thermosphere is the thickest layer in which helium gas is abundant in amount.

Note:
The atmosphere protects us from genetic damage by solar ultraviolet radiation, solar wind and rays. The climate is also affected by the earth atmosphere composition.The chemical composition in the atmosphere determines the air quality. The atmosphere plays an important role in the water cycle.