Chapter 1.1, Problem 3SSC

Interpretation Introduction

Interpretation:

The formation of ozone layer needs to be explained along with its importance.

Concept introduction:

A deepest zone in the stratosphere, surrounding the Earth which has massive measures of ozone (gas) in it is described as the ozone layer. It is approximately 10 km above from the Earth’s surface.

Answer to Problem 3SSC

The ozone layer is naturally formed by a reactive process in the stratosphere. The ozone layer is important because it protects our Earth from harmful UV rays.

Explanation of Solution

Ozone layer formed naturally in the stratosphere. The reactive process, formation of ozone layer is mentioned below:

Step 1: Solar ultraviolet radiation (or sunlight) breaks an oxygen (O) molecule and results in the formation of two oxygen atoms.

Step 2: Individually atom later undergoes a collision with another present oxygen molecule and bind to it. This process forms an ozone molecule.

$\begin{array}{l}\text{O}-\mathrm{O}\stackrel{\begin{array}{l}\text{UV}\\ \text{sunlight}\end{array}}{\to }\mathrm{O}+\text{O}\\ \text{O}+\text{O}-\text{O}\to {\text{O}}_{\text{3}}\end{array}$

Step 3: After this process, 3 oxygen molecules in the presence of sunlight react to form 2 ozone molecules. This becomes ozone layer. Reaction of this process is mentioned below:

$3{\text{O}}_{\text{2}}\stackrel{\text{sunlight}}{\to }2{\text{O}}_3$

Importance of ozone layer is given below:

It protects our Earth from harmful UV light (comes from sun).

It protects health of all life present on the Earth from UV rays which is 97% harmful. 

Conclusion

Ozone layer is a ring of protective gases. Mainly, this layer protects Earth from UV rays.