Ozone is an important molecule in maintaining the homeostasis in the
             environment. Ozone, the molecule O3, makes a layer in the stratosphere,
             situated 10 to 15 kilometers from the earth's surface. The dioxide
             molecule, O2 and Oxygen atom O, collide with each other result in the
             formation of Ozone, O3. In this reaction, the molecule O3 contains an excess
             of energy. Once the molecule is formed, it is not stable enough to last
             long. The energy-rich O3 molecules discards the excess energy by colliding
             with another atom or molecule and transferring the energy in the form of
             heat. In the results of the decomposition of ozone into O2 and O in the
             ozone layer, solar radiation is absorbed. This process of the chemical bond
             breaking causing the absorption of a photon by a molecule is called
             photodissociation. Radiation with sufficient intensity, is capable of
             separating the O3 molecule, resulting in photodissociation. The cyclic
             process formation and decomposition of ozone provides a shield against
             ultraviolet radiation that enter the earth's atmosphere. If it were not for
             the chemical reaction of radiation and ozone in the stratosphere, these
             high-energy photons would penetrate the earth's surface. The ozone layer
             absorbers about 99% of the harmful radiation which makes it possible for
             animals and plants to live on the planet.
             In 1974, F. Sherwood Rowland and Mario Molina of the University of
             California proposed that chlorine from chlorofluorocarbons (CFCs) could
             deplete the ozone layer. Beginning in 1957 to 1985, the British Antarctic
             Survey had measured the average ozone concentration over Halley Bay in
             Antarctica. Up until 1974, the ozone concentration remained stable. Yet
             after 1974, the team observed a decline of the ozone layer to levels less
             than 10%. From this study the awareness over the danger of the "hole" and
             ultraviolet radiation and the destruction being done to the earth.
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