Question

Which of the following is absorbed by the ozone layer?
(A) only gamma rays
(B) visible light
(C) radio waves
(D) ultraviolet

Answer 1

Hint
The ozone layer exists in the stratosphere in the Earth’s atmosphere. It is made up of three oxygen molecules. When the ultraviolet light falls on the ozone molecules, they absorb the energy and then get converted to oxygen molecules and a single oxygen atom.

Complete step by step answer
The ozone layer is also known as the ozone shield. It is present in the earth’s stratosphere and is made up of oxygen molecules in the form ${O_3}$. It is found in the lower part of the Earth’s stratosphere and the density of the ozone layer varies geographically and seasonally. It is generally thicker near the poles and thinner near the equator.
Although the concentration of ozone is very small still it is vital for the survival of life on earth. This is because the ozone layer absorbs the most energetic ultraviolet light that is coming from the sun towards the earth. When the ultraviolet light strikes the ozone molecule, then it breaks apart the ${O_3}$ molecule to a ${O_2}$ molecule and an oxygen atom. The oxygen atom then again recombines with an oxygen molecule ${O_2}$ and forms a ozone molecule again.
Hence, the ozone layer absorbs the ultraviolet light and so the correct answer will be option (D).

Note
It is seen in the recent research that the ozone layer is being depleted by the chemicals that are being released by the industries, mainly chlorofluorocarbons. The depletion of the ozone layer from the stratosphere will reduce the absorption of the harmful ultraviolet rays coming from the sun. The ultraviolet radiation threatens life on earth as it increases the risk of skin cancer and many other ecological problems.