Karnataka Secondary Education Examination BoardKarnataka SSLC

# Ozone Layer Depletion

#### notes

OZONE LAYER:-

Ozone (O3) is a molecule formed by three atoms of oxygen. While O2, which we normally refer to as oxygen, is essential for all aerobic forms of life. Ozone, is a deadly poison. However, at the higher levels of the atmosphere, ozone performs an essential function. It shields the surface of the earth from ultraviolet (UV) radiation from the Sun.

This radiation is highly damaging to organisms, for example, it is known to cause skin cancer in human beings.

Ozone at the higher levels of the atmosphere is a product of UV radiation acting on oxygen (O2) molecule. The higher energy UV radiations split apart some molecular oxygen (O2) into free oxygen (O) atoms. These atoms then combine with the molecular oxygen to form ozone as shown

$\ce{O2 ->[UV] O + O}$

$\ce{O + O2 -> \underset{\text{Ozone}}{O3}}$

The amount of ozone in the atmosphere began to drop sharply in the 1980s. Formation of holes in the ozone layer was reported. This decrease has been linked to synthetic chemicals like chlorofluorocarbons (CFCs) which are used as refrigerants and in fire extinguishers. In 1987, the United Nations Environment Programme (UNEP) succeeded in forging an agreement to freeze CFC production at 1986 levels. It is now mandatory for all the manufacturing companies to make CFC-free refrigerators throughout the world.

#### description

• Depletion of Ozone Layer
• Chemicals responsible for the destruction of the ozone layer
If you would like to contribute notes or other learning material, please submit them using the button below.

### Shaalaa.com

Our Environment part 10 (Ozone layer) [00:15:01]
S
0%