Final answer:
Chlorofluorocarbons are organic compounds made up of carbon, fluorine, and chlorine. They have been used as refrigerants and aerosol propellants but have been phased out due to their damaging effects on the ozone layer.
Step-by-step explanation:
Chlorofluorocarbons (CFCs) are organic compounds that consist of carbon, fluorine, and chlorine. They are characterized by their stability and low reactivity, properties that made them popular in various applications such as refrigerants, solvents, and propellants in aerosol cans. The most common example of a CFC is dichlorodifluoromethane (Freon-12).
CFCs have been found to have a detrimental effect on the ozone layer in the upper atmosphere. In the stratosphere, UV radiation breaks CFCs down, which leads to the release of chlorine atoms that catalyze the destruction of ozone (O3) molecules. This process contributes to the depletion of the ozone layer, which is vital for blocking harmful ultraviolet radiation from reaching the surface of the Earth.
Due to their environmental impact, CFCs have been phased out under international agreements like the Montreal Protocol, and are being replaced by other substances such as hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs), which are less harmful to the ozone layer.