Chapter 1, Problem 26A

Interpretation Introduction

Interpretation: The location of ozone in the Earth’s atmosphere needs to be explained.

Concept introduction: The layer/film of gases around our Earth is defined as an atmosphere. Life on Earth is impossible without it. On the basis of temperature, the atmosphere comprises four main layers which are mentioned below:

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere

Answer to Problem 26A

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

Explanation of Solution

90 % of ozone is located in the stratosphere. Above Earth's surface, the stratosphere about 10 to 16 kilometers long (on altitude). Excluding this, the stratosphere extends up to 50 kilometers (nearby). The ozone layer is naturally formed (or produced) in the stratosphere. The following image will help you to locate ozone in Earth’s atmosphere:

  

In the stratosphere, formation(by the reactive process) of the ozone layer is mentioned below:

Step 1: Solar ultraviolet radiation (or sunlight) breaks apart oxygen (O) molecule to form 2 separate oxygen atoms.

Step 2: Individually, the atom later undergoes a binding collision with another present oxygen molecule. This process forms an ozone molecule.

  

Step 3: After this process, 3 oxygen molecules plus sunlight react together to form 2 ozone molecules. This becomes the ozone layer. The reaction of this process is mentioned below:

  $3{\text{O}}_2\to 2{\text{O}}_{\text{3}}$

The above reaction takes place in the presence of sunlight.

Conclusion

The ozone layer is a ring of protective gases which protects Earth from UV light.