THE OZONE LAYER
Ozone molecules consist of three oxygen atoms as signified
by the chemical symbol O3. Ozone molecules exist naturally in the upper levels of the atmosphere known as
stratosphere that stretches from about 15 to 55 km above the Earth's surface. At this altitude both ozone
and oxygen coexist in a dynamic equilibrium maintained by high energetic UV radiation from the sun.
In fact, the amount of ozone in the stratosphere is frighteningly small.
The highest concentration of ozone, found at an altitude of 20 to 25 km, is only 10 parts per million (ppm).
If we could gather all stratospheric ozone on the ground under atmospheric conditions, it would amount to a
layer no thicker than a mere 3 mm. To simplify, we imagine the ozone layer as a thin curtain around our
Earth's atmosphere. However, in reality ozone is scattered over the stratosphere in low concentrations.