Ozone Essay, Research Paper
Ozone, pronounced OH Zohn, is a signifier of O that is present in the Earth & # 8217 ; s atmosphere in little sums. Ozone in the upper ambiance is a major factor in doing life on Earth possible. But ozone in the lower ambiance contributes to air pollution. Ozone is used commercially in H2O purification procedure and as a bleaching agent.
Ordinary O molecules have two O atoms, ozone has three. Ozone is produced of course through photochemical and electric discharge reactions. Photochemical production occurs when high energy radiation from the Sun work stoppages ordinary O in the Earth & # 8217 ; s upper atmosphere and converts some of it to ozone. Electric discharge reactions, including lightening and electric flickers from motors, besides convert some O to ozone. Ozone is produced commercially by electric discharges in a machine called an ozonizer.
Ozone has a molecular weight of 47,998, pure ozone is a pale blue gas. It was foremost detected by agencies of its crisp, annoying olfactory property, which is frequently noticed near electrical switches and machinery. The German chemist Christian Friedrich Schonbein discovered ozone in 1840.
Ozone in the upper ambiance has the highest concentration reached depending on the latitude, between 9 and 18 stat mis ( 15 and 30 kilometres ) above the Earth & # 8217 ; s surface. This concentration is 10 parts per million by volume, that is 10 parts ozone per 1 million parts air. This ozone bed in the upper ambiance shields the Earth from 95 to 99 per cent of the Sun & # 8217 ; s UV beams. Overexposure to these beams is a cause of skin malignant neoplastic disease.
Most ozone in the lower ambiance is considered an air pollutants. It is formed by chemical reactions between sunshine and pollutants already in the ambiance. Ozone produced in this mode is a constituent of photochemical smog. Such ozone can straight damage gum elastic, plastic, and program
T and carnal tissue. It may undergo farther chemical reactions that produce other detrimental chemicals. Exposure to certain concentrations causes concerns, firing eyes, and annoyance of the respiratory piece of land in many persons
In the mid 1970 & # 8217 ; s, some scientist expressed concern that chemical compounds called CFCs ( chlorofluorocarbon & # 8217 ; s ) were interrupting down the protective bed of ozone. At that clip, CFC & # 8217 ; s were widely used as propellents in aerosol spray tins. After CFC & # 8217 ; s are released, they slowly lift into the ambiance. When they reach the upper ambiance, the Sun & # 8217 ; s UV radiation breaks them apart. Some of the molecular fragments that result respond with ozone, thereby cut downing the sum of it.
Since the 1970 & # 8217 ; s, scientist have observed that the ozone bed over antarctica thins dramatically every twelvemonth in the spring. Equally much as 50 per cent of the molecules may vanish, making what is called an ozone hole. Scientist believe that antarctica & # 8217 ; s unusual conditions conditions increase the reactions between CFC & # 8217 ; s and ozone. These conditions include utmost cold, twirling air current forms, and complete darkness during the winter. When sunshine foremost appears in the spring, it triggers the chemical reations that destroyed the ozone.
Scientist have besides discovered that a much less terrible ozone hole occurs over the north-polar in late winter. Some experts fear that the ozone bed may finally thin over more populated countries, jeopardizing human wellness and harming many workss and animate beings. Scientist step alterations in ozone in the upper ambiance with instruments on aircraft, balloons, and orbiters.
In 1978, the united provinces authorities banned fluorocarbon aerosols for most utilizations. However, the prohibition did non impact the usage of CFC & # 8217 ; s as refrigerants or in insularity. In 1990, the united provinces and 55 other states agreed to stop the production of CFC & # 8217 ; s by the twelvemonth 2000.
