Ozone :: essays papers

Ozone 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. Scientists believe the expanding ozone hole, which is centered over Antarctica was caused by Chloroflurocarbons. CFCs are released into the environment through such sources as spray cans , air conditioners, factories, refrigerants and cleaning products. CFCs are dangerous to the atmosphere because after they are released into the environment, the sunlight breaks down the compound. The chlorine molecules react with the ozone molecules by permanently breaking down the molecule, thus diminishing the ozone layer. This rise poses a major threat environment. In 1985, in Vienna and in 1987 in Montreal, a Protocol was signed proposing the gradual termination of use of CFCs over the decades. A dramatic reduction in the use of CFCs was agreed on. Regulations to limit the production of