Question

Assertion (A): The temperature in the stratosphere increases with altitude.
Reason (R): Ozone present absorbs ultraviolet radiation which is converted into heat.
Choose the correct option from the following:
A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion
B. Both Assertion and Reason are true but Reason is not correct explanation of Assertion
C. Assertion is true and Reason is false
D. Assertion is false and Reason is true

Answer 1

Hint: We know that atmosphere is the layer of gases that surrounds the Earth. The atmosphere blocks the entering of harmful sun rays to the Earth. It also maintains the temperature of Earth. The three main constituents of the atmosphere are argon, nitrogen, and oxygen.

Complete step by step answer:
We know that there are many layers of the atmosphere. They are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.

Let’s learn the stratosphere in detail. The 2nd lowest layer of the atmosphere is the Stratosphere. It lies above the troposphere. Within the stratosphere, the ozone layer lies. In this layer, ozone molecules absorb ultraviolet radiation (high energy) of the sun and convert it into heat. This is the reason due to which this layer is very hot. On moving higher in this layer the temperature increases.

So, we get to know that, both assertion and reason are true and reason explains the assertion.

So, the correct answer is Option A.

Additional Information:
In the atmosphere, the lowest layer is the troposphere. From the ground level, it extends up to 10 kilometers above the sea level. This layer consists of 75% of the air in the atmosphere. In this layer, as we go above the temperature dropdown.
Above the troposphere, stratosphere layer present. In this layer, as we go upward temperature increases.
Above the stratosphere, the layer exists is the mesosphere. In this layer, the coldest part of our atmosphere exists.
Above the mesosphere, the thermosphere layer exists. The temperature increases as we go up in this layer because of the absorption of high energetic UV and X-ray radiation.
Above the thermosphere, the layer present is the exosphere. This is the final frontier of the gaseous envelope of Earth.

Note: The UV radiation of the Sun is very harmful to all living beings. It is the major cause of skin cancer. The ozone molecules present in the atmosphere absorb the UV radiation and prevent them from reaching the surface of Earth.