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Chlorofluorocarbons (CFCs): when derived from methane and ethane these compounds have the formulae CCl m F 4−m and C 2 Cl m F 6−m, where m is nonzero. Hydro-chlorofluorocarbons (HCFCs): when derived from methane and ethane these compounds have the formula CCl m F n H 4−m−n and C 2 Cl x F y H 6−x−y, where m, n, x, and y are nonzero.
Its main source remained uncertain, but production of hydrofluorocarbons in East Asia was suspected. [4] Between 2012 and 2017, concentrations of the gas jumped by 40 percent. [5] In 2020, the global mean concentration of CFC-113a was 1.02 parts per trillion with global emissions of 2.5 ± 0.4 ODP-Gg yr −1. [6]
Trichlorofluoromethane, also called freon-11, CFC-11, or R-11, is a chlorofluorocarbon (CFC). It is a colorless, faintly ethereal, and sweetish-smelling liquid that boils around room temperature. [5] CFC-11 is a Class 1 ozone-depleting substance which damages Earth's protective stratospheric ozone layer. [6]
CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years, [ 9 ] sufficiently long that it will cycle out of the troposphere and into the stratosphere . In the stratosphere, CFC-113 can be broken up by ultraviolet radiation (UV, sunlight in the 190-225 nm range), generating chlorine radicals (Cl•), which ...
1,1-Dichlorotetrafluoroethane is a chlorofluorocarbon also known as CFC-114a or R114a by American Society of Heating, Refrigerating, and Air Conditioning Engineers. [2] It has two chlorine atoms on one carbon atom and none on the other.
The Western diplomatic source, speaking on condition of anonymity, told Reuters the acceleration of enrichment was "in contradiction with Iran's declarations on its willingness to return to ...
HFCs were developed in the 1990s to substitute for substances such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). As these substances were found to deplete the ozone layer, the Montreal Protocol began to lay down provisions for them to be phased-out globally after the agreement was ratified in 1987.
The disease does not pass from person to person but rather through bacteria found in water and soil sources. In a statement to PEOPLE, a representative with Pinellas County Schools said Department ...