The ozone layer

The stratospheric ozone layer surrounds the earth at a height of approximately 30 - 35 km. It is produced by the reaction of oxygen with intensive solar radiation. Nearly all the radiation in the region between 100 and 200 nm is absorbed by O2.

+ energy 3 O2 --> 2 O3 - energy

Stratospheric ozone is a lifesaving gas because of its ability to absorb the sun's ultraviolet radiation in the region of 240 to 310 nm. Reaching the earth this radiation could destroy living cells and tissue.

About ozone

Pure ozone is a light blue gas at room temperature. It has a sharp characteristic odour, which often is noticed after electrical storms or near high voltage generators. Liquid ozone (boiling point -112°C) is a deep blue, explosive liquid. Ozone is so reactive that it cannot be transported , but must be generated as needed. Relatively non-reactive metals, such as silver and mercury, which don't react with oxygen, react with ozone to form oxides.

Ozone is used as a bleaching agent and is replaces chlorine in water treatment.

Back to Teachers