Question

Explain the formation of ozone in the atmosphere.

Answer 1

Hint: We need to remember that the ozone is a compound which belongs to the oxygen family. It is present in the atmosphere of earth. It is of a huge importance in the ecosystem. It is responsible for the greenhouse gas effect. Ozone layer is present in the atmosphere which acts as a shield protecting the earth’s atmosphere from harmful radiations and UV lights propagated by the sun.

Complete step by step answer:
We know that the ozone layer is present in the atmosphere. But if we study geographically about the layers in the earth’s atmosphere, there is no such layer called ozone layer.
This is because ozone is a gas and this gas is present in the atmosphere in two respective layers of the atmosphere, namely the Stratosphere and Troposphere. So we have two ozone layers, one is stratospheric ozone and another is tropospheric ozone.
Stratospheric ozone – It is formed naturally by reaction of oxygen with solar ultraviolet radiations. The oxygen is present in the atmosphere as a molecule which is in diatomic form. The ultraviolet radiation which comes from sunlight breaks oxygen molecules to produce two oxygen atoms. After which the reactive oxygen atom combines with an oxygen molecule to form an ozone which is a triatomic form of oxygen. This reaction takes place in the atmosphere only in the presence of sunlight.
The chemical reaction is a two step process which can be expressed as,
${O_2}\xrightarrow{{sunlight}}2O$
$2O + 2{O_2} \to 2{O_3}$
Tropospheric ozone – Troposphere layer is near the earth’s surface. Here, ozone is formed by chemical reactions taking place naturally by gases sources from pollution. Fossil fuels when combusted produce pollutant gases which are responsible for production of ozone in the tropospheric layer.

Note:
Though we have studied that ozone is produced naturally in two ways, it also highlights the fact that ozone is produced by pollutant gases. It does protect the environment but when it reacts with other pollutant gases it decomposes easily. Burning of fuels and other natural substances, chemical gases liberated from gas chambers of chemical industries and other gases produced due to industrial and non-industrial sources contribute to the decomposition of ozone, which can produce many harmful effects in future.