Final answer:
CFCs and HCFCs are both ozone-depleting substances and have been used as refrigerants in various cooling systems. They contain chlorine which can destroy ozone molecules in the stratosphere, leading to global efforts to phase them out.
Step-by-step explanation:
Common Characteristics of CFCs and HCFCs
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) share several attributes, but the most significant commonalities include that they are both ozone-depleting substances and had applications as refrigerants. These substances contain chlorine, fluorine, and carbon. The chlorine atoms contained in these compounds are capable of destroying ozone molecules in the stratosphere, thereby depleting the vital ozone layer that protects the Earth from harmful ultraviolet radiation.
Ozone depletion has been a major environmental concern, leading to the Montreal Protocol, an international treaty to phase out the production of CFCs and HCFCs, alongside other ozone-depleting substances. While CFCs are now less commonly used because of their high potential for ozone depletion, HCFCs have served as replacements, as they are somewhat less harmful to the ozone layer due to their increased reactivity in the lower atmosphere, which reduces the chance of them reaching the stratosphere.
Both CFCs and HCFCs have also been used extensively as refrigerants in various cooling systems, including air conditioners and refrigerators. Despite this shared use, it's important to note that neither CFCs nor HCFCs are highly flammable, which sets them apart from many other chemical refrigerants.