CBSE Class 10 Answered

Ozone layer is naturally found in the upper part of the atmosphere called stratosphere. It is created when ultraviolet radiation (sunlight) strikes the stratosphere, dissociating or splitting oxygen molecules (O2) to atomic oxygen (O). The atomic oxygen quickly combines with further oxygen molecules to form ozone.

The decrease in the quantity of ozone in the upper layer of the atmosphere is called depletion of ozone. This is also known as the ozone hole. Due to this hole, ultraviolet rays of the Sun can reach the Earth and cause diseases such as skin cancer. Pollutants such as oxides of nitrogen, chlorine free radicals etc. are produced in the atmosphere. Molecules of ozone react with these pollutants and are destroyed. This causes depletion of the ozone layer.