MCQ Detailed View

The ozone layer is a region of Earth’s atmosphere that plays a vital role in protecting life on the planet. Its composition is made up of molecules called ozone (O₃). Each ozone molecule consists of three oxygen atoms bonded together. This is different from the normal oxygen we breathe, which is O₂, containing only two oxygen atoms.

Ozone is located mainly in the stratosphere, a layer of the atmosphere that lies about 10 to 50 kilometers above the Earth’s surface. This region is known as the ozone layer because it contains higher concentrations of ozone compared to other parts of the atmosphere. Although ozone makes up only a very small fraction of the atmosphere, its presence is extremely important for life.

The key role of ozone is to absorb harmful ultraviolet (UV) radiation from the Sun. UV rays can cause serious damage to living organisms, including skin cancer in humans, cataracts in the eyes, and harm to plants and aquatic ecosystems. By blocking most of the Sun’s dangerous UV-B and UV-C rays, the ozone layer acts like a protective shield for Earth.

Ozone is formed naturally when ultraviolet light splits ordinary oxygen molecules (O₂) into single oxygen atoms, which then combine with other oxygen molecules to form O₃. This natural cycle of ozone creation and destruction helps maintain balance in the atmosphere. However, human activities, such as the release of chlorofluorocarbons (CFCs), have damaged the ozone layer in the past, leading to the formation of the ozone hole over Antarctica. International agreements, like the Montreal Protocol, have helped reduce the use of harmful chemicals and allowed the ozone layer to gradually recover.

In summary, the composition of the ozone layer is ozone molecules (O₃), and it is essential for shielding Earth from harmful ultraviolet radiation, making it one of the most important protective features of our atmosphere.