This section focuses on providing information about the nature of activated oxygen and ozone, with a focus on the importance of atmospheric oxygen. Silver in the News
Several fatal accidents occurred in the s because of methyl chloride leakage from refrigerators. People started leaving their refrigerators in their backyards. A collaborative effort began between three American corporations, Frigidaire, General Motors and DuPont to search for a less dangerous method of refrigeration.
InThomas Midgley, Jr. Freon represents several different chlorofluorocarbons, or CFCs, which are used in commerce and industry.
The CFCs are a group of aliphatic organic compounds containing the elements carbon and fluorine, and, in many cases, other halogens especially chlorine and hydrogen. Freons are colorless, odorless, nonflammable, noncorrosive gases or liquids. Chlorofluorocarbons CFCs are highly stable compounds that were used as propellents in spray cans and in refrigeration units.
They are several organic compounds composed of carbon, fluorine, chlorine, and hydrogen. CFCs are manufactured under the trade name Freon.
The invention of chlorofluorocarbons CFCs in the late s and early s stemmed from the call for safer alternatives to the sulfur dioxide and ammonia refrigerants used at the time, CFCs found wide application after World War II. Chloroflourocarbons were first created in as non-toxic, non-flamable refrigerants, and were first produced commercially in the 's by DuPont.
The first Chlorofluorocarbon was CFC, a single carbon with two chlorines and two Fluorines attached to it. These halogenated hydrocarbons, notably trichlorofluoromethane CFC, or F and dichlorodifluoromethane CFC, or Fhave been used extensively as aerosol-spray propellants, refrigerants, solvents, and foam-blowing agents.
They are well-suited for these and other applications because they are nontoxic and nonflammable and can be readily converted from a liquid to a gas and vice versa. Chlorofluorocarbons or CFCs also known as Freon are non-toxic, non-flammable and non-carcinogenic.
They contain fluorine atoms, carbon atoms and chlorine atoms. CFCs have been found to pose a serious environmental threat. Studies undertaken by various scientists during the s revealed that CFCs released into the atmosphere accumulate in the stratosphere, where they had a deleterious effect on the ozone layer.
Stratospheric ozone shields living organisms on Earth from the harmful effects of the Sun's ultraviolet radiation; even a relatively small decrease in the stratospheric ozone concentration can result in an increased incidence of skin cancer in humans and in genetic damage in many organisms.
In the stratosphere the CFC molecules break down by the action of solar ultraviolet radiation and release their constituent chlorine atoms.
These then react with the ozone molecules, resulting in their removal. CFCs have a lifetime in the atmosphere of about 20 to years, and consequently one free chlorine atom from a CFC molecule can do a lot of damage, destroying ozone molecules for a long time.
Although emissions of CFCs around the developed world have largely ceased due to international control agreements, the damage to the stratospheric ozone layer will continue well into the 21st century.In this lesson, you will learn the importance of the ozone layer and how it is depleted.
You will also study the research and policy that has been instrumental in its recovery. In some parts of the United States, 'ozone alert days' are declared when levels are forecast to become hazardous, and the population are encouraged to limit their use of the main culprits, such as motor vehicles and aerosols.
This%text%is%derivative%from%content%onWindows%to%the%Universe®%(caninariojana.com)©,% National%Earth%Science%Teachers%Association.%%. The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's (, ft) altitude. UV-B radiation can be harmful to the skin and is the main cause of sunburn; excessive exposure can also cause cataracts, immune system suppression, and "The Importance of the Montreal Protocol in Protecting.
Importance of Forests Forests and biodiversity are key to all life forms. The richer the diversity of life, the greater the opportunity for medical discoveries, economic development and adaptive responses to such new challenges as climate change.
Below are some more importance of forests. The new trade deal between Canada, the United States and Mexico does not appear to explicitly mention the terms "climate change" or "global warming." But the United States-Mexico-Canada Agreement (USMCA), meant to replace NAFTA, does contain an "environment" chapter.