Question

The layer of air around earth is known as-

Answer 1

Hint: The layer of air around the earth consists of different gases. It is responsible for the climatic changes. It is further divided into 4 layers depending upon its distance from the ground.

Complete-step- by- step answer:
The Earth is surrounded by a layer of air which consists of different gases like nitrogen, oxygen, carbon dioxide, noble gases and other gases. Out of these, nitrogen is most abundant.
This layer of gases surrounding earth is known as atmosphere and it consists of mainly 4 more layers depending on their temperatures. We will discuss these layers below-

1. The Troposphere- It is the lowest part of the atmosphere, the part where we live. It contains most of the natural climatic changes like rainfall, snowfall, clouds. In this part, the temperature change varies day to day. The troposphere contains 75% of all the air in the atmosphere. 0-10 km from the ground is the troposphere.

2. The layer above the troposphere is-
The Stratosphere- This extends upward from the tropopause (which is the top most layer of the troposphere) to about 50km. This layer contains most of the ozone gas present in the atmosphere. The increase in temperature with increasing height is due to the absorption of ultraviolet rays by this ozone layer.

3. The Mesosphere- This layer stretches from 50-80kms from the earth’s surface. Here, the temperature decreases with height, reaching a minimum of -90 degrees.

4. The Thermosphere- Above the mesosphere, lies the thermosphere which is 80-700kms from the ground. This is also referred to as ionosphere as the energetic solar radiation turns the atoms and molecules in this layer into a positive ion by eliminating an electron. This layer absorbs radio waves, allowing it to receive shortwave radio broadcasts.

The other layers present are the Exosphere which is the region above 700kms and the region above 1000km is the Magnetosphere.
As we can see from the above discussion, the layer of air surrounding the earth is known as earth’s atmosphere.

Therefore, the correct answer is atmosphere.

Note: It is important to remember here that the lowermost layer is the troposphere but the layer around earth is atmosphere composed of different gases. We should not be confused between the two of them.