Wait a second!
More handpicked essays just for you.
More handpicked essays just for you.
Role of chemists
Don’t take our word for it - see why 10 million students trust us with their essay needs.
Chemists are the specialists in chemistry, that interact with chemical properties, and reactions. The earth is made up of different gases. Some of this gases are needed for life in the planet but other gases can be harmful to the living. Gas’s use in regular quantities are favorable to the earth. The world started to become more advance and had to use more of this gases to produce everyday objects and inventions by men. Little did we knew this chemicals we going to affect us in our life. Chemist Jose Mario Molina actually discovered that chlorofluorocarbons were affecting the ozone layer. Mario Molina was born on March 19, 1943, in Mexico City. Molina was interested in science since a very young age that he created his own and personal chemistry lab in a bathroom at his house. Molina's aunt was a chemistry and figured out her nephew’s great interest in science. She was a key figure in his life because she helped him to perform chemistry experiments that weren't taught at his school. He completed his studies in Mexico and Germany before moving to the United States to achieve an advance degree in physical chemistry. At Berkeley University, Molina saw the connection of science on human life and society. He found that it was irrelevant the research some people were doing for the development of weapons that would not help society and other destructive purposes. Mario wanted to work on something that would benefit society. Molina wanted to made a difference and do something that helped the living not something that would destroy them. He found the interest on the chlorofluorocarbons that are used in refrigerators. In 1973, he joined with professor Sherwood Rowland to begin a research in chlorofluorocarbons. This chemicals were thought to be harmless to our environment but they were stored in the ozone layer and didn't know what happened to them. While doing his research Molina learned that these compounds move up to the ozone and stay there. He expected the compounds to be destroy by the solar radiation. However to his surprise he formed that chlorofluorocarbons would simplify into component element when exposed to radiation. This simplify components produce a highly concentration of pure chlorine atoms. From there he already knew that the ozone layer can be destroy with chlorine. The ozone layer is the one that protects living things from the pure ultraviolet rays of the sun.
Early Life Francisco Vasquez de Coronado was born in Salamanca, Spain, around 1510. His parents are Juan Vasquez de Coronado y Sosa de Ulloa and Isabel de Lujan. His father was a wealthy aristocrat, but the family fortune was promised to his older brother. Francisco was determined to make his own fortune in the New World. This is what made him an explorer.
Life on this planet Earth is the product of a delicate balancing act provided by nature. Mankind's very existence is totally dependent on this fragile ecosystem's ability to maintain itself. A valuable player in the balance of the environment, the ozone layer, is facing a very serious threat by man. Chloroflourocarbons (CFCs), are chemical agents commonly found in refrigerants, aerosol sprays, and in the manufacturing of Styrofoam and industrial solvents. With the rate of more than a half-million tons of CFCs being spewed into the atmosphere yearly, the rate of ozone depletion is rising at an alarming rate. If a global effort is not made to end the unnecessary use of CFCs, the inhabitants of this planet face an extremely difficult and frightening future.
In summary, ozone is a multi-dimensional gas with its many influences on humanity and life in general. Some of its effects are considered essential while others are highly undesirable. Human-directed changes in the abundance of ozone, i.e., lower amounts in the upper atmosphere and higher amounts in the lower atmosphere, have created more problems for us and other organisms on the planet. There are clearly things that humans can and are doing that can alleviate these problems. Perhaps ozone can now begin to be understood for the vital (yet dangerous) resource that it is.
Los Clorofluorocarbonados (CFC) y sus derivados tienen como fuentes principales algunos productos industriales, y los óxidos de nitrógeno, que se producen por multitud de causas, principalmente por la quema de combustibles fósiles y la utilización de fertilizantes químicos.
Chlorofluorocarbons (CFC’s) are a man-made substance that did not previously exist to the industrial area. They are a product of a collaboration of three American companies – Frigidaire, General Motors, and Du Pont -- after a series of fatal accidents during the 1920’s where toxic gases, (Methyl Chloride), used as refrigerants leaked from refrigerators. Thomas Midgley, Jr. of General Motors first synthesized CFC’s in 1928, and later, on December 31, 1928, Frigidaire was issued the first patent for this formula. CFC’s went under the trade name of Freon (11 and 12), licensed by Du Pont, and by 1935, they and their competitors had sold over eight million new refrigerators in the United States containing the substance. Because of the CFC safety record for non-toxicity, especially when compared to that of previously used substances for coolants, Freon became the preferred substance in large air-conditioning systems. Public health codes in many American cities were even revised to mandate the use of Freon. Soon thereafter the production and use of CFC’s took off, ranging from propellants for bug sprays, paints, hair conditioners, and in air-conditioning in automobiles. (See appendices 1) Peak annual sales of the product worldwide reached over one billion dollars US, and more then one million metric tons were produced.
What is the ozone layer? The ozone layer is a part of the stratosphere containing highly poisonous O3 gas with a strong odor. Ozone is formed by the action of solar ultraviolet light on oxygen. Ozone at ground level is a health hazard. High concentrations of ozone at ground level are dangerous to breathe and can damage the lungs. However, the ozone layer inhibits most ultraviolet and other high energy radiation from entering to the earth's surface.
The basic set of reactions that involve this process are: Cl + O3 -->ClO + O2 and ClO + O -->Cl + O2 The net result: O3 + O -->2O2 Chlorine is initially removed in the first equation by the reaction with ozone to form chlorine monoxide. Then it is regenerated through the reaction with monatomic oxygen in the second equation. The net result of the two reactions is the depletion of ozone and atomic oxygen.6 Chlorofluorocarbons (CFCs), halons, and methyl bromide are a few of the ozone depletion substances (ODS) that break down ozone under intense ultraviolet light.
Not enough people realise the importance of chemicals and green chemistry in everyday life. Most people think of chemicals as poisonous pesticides and or pollution. But it’s not. Chemicals can be used to help the environment.
Pasteur was born on December 27, 1822 in Dole, France, and grew up in the small town of Arbois. As a young boy, Pasteur showed no particular interest in science. His talents were mainly drawing and painting. At age thirteen, he could draw remarkable pictures of his sisters, mother, and the river that ran by his home. During his youth, he developed an ambition to become a teacher. While still in his teens, he went to Paris to study in a famous school called Lyce St. Louis. During his studies to become a teacher, he was fascinated by a chemistry professor, Monsieur Jean-Baptist Dumas. He wrote home excitedly about these lectures, and decided that he wanted to learn to teach chemistry and physics, just like his favorite professor.
Ozone depletion has adverse effects on agriculture, forestry, marine ecosystems and polar ice caps. Aquatic food webs are affected in terms of development and growth; this disrupts biological processes. Due to more ultraviolet radiation reaching the earth’s surface, polar ice caps melts and this increases the sea level, which in turn can cause major flooding in low coastal regions. There is a decline in phytoplankton, as water is transparent and due to the high amounts of UV radiation reaching 0.5 meters below surface, it intoxicates the phytoplankton. (Bais et al.,
...bons which produce free radicals of chloride from UV light. Chloride free radicals interact with ozone layer O3 to break the ozone layer down: CL-CL –> CL. Chloride from CFC form free radicals when UV light interacts with them: CL. + O3 –> CLO + O2. Chloride free radical interacts with ozone to produce O2 free radical: O-O-> O. Oxygen free radical produced by UV light: O. –>O3 – O2 + O2. Oxygen radical also attacks the ozone layer to produce more oxygen radicals.
The ozone layer is in stratosphere, region of the atmosphere 11km - 50km above the surface of the Earth. Firstly, this layer of ozone reflects most ultraviolet sunlight (UV-B) from the Sun, allowing small amounts to reach the surface of the Earth. This UV-B is damaging to all life forms on Earth. Without this layer of ozone in the stratosphere UV-B radiation would negatively affect humans, animals, plants, and sea life. Secondly, the ozone layer is being deteriorated by the accumulation of chlorofluorocarbons (CFCs) (CFC is a compound of chlorine, fluorine, and carbon. CFCs are used in propellants, foaming agents, aerosol sprays, solvents, and coolants in freezers and refrigerators), halons,...
“Like an infection that grows more and more virulent, the continent-size hole in Earth’s ozone layer keeps getting bigger and bigger”(Beyond Discovery). The ozone is a protective layer that occurs naturally in the stratosphere, 6 to 28 miles in altitude. Each year, since the late 1970’s, much of the ozone layer above Antarctica has disappeared, creating what is popularly known as the “ozone hole.” This hole now measures about 9 million square miles, nearly the size of North America. Less dramatic, but still significant, depletion of ozone levels has been recorded around the globe. With less ozone in the atmosphere, more ultraviolet radiation strikes Earth, causing more skin cancer, eye damage, and possible harm to crops.
The organic compound Chlorofluorocarbon is known as CFC. This compound is made of chlorine fluorine and carbon only. CFC is in the group volatile organic compound. The CFC was first invented or made in 1928. The main purpose of CFC was to uses as refrigerants for refrigeration. Freon is the trade name of CFC .There are some main reasons behind the wide use of CFC. Non-toxic and flammability were the main reason. Around in 1960s the use of CFC increases among the developing nations. As the use of CFC increases it start to destroy the ozone layer. Fluorine and chlorine atom are separated in the reaction they remain stratosphere for long time and lowly destroy ozone layer. After that different other alternatives to CFC were, those alternatives were not harmful to ozone layer but they have a great influence on global warming.
Alfred advanced in chemistry, physics, poetry, and literature. After tutoring, he moved to Paris to study chemistry where he was introduced to and w...