Final answer:
Chlorofluorocarbons (CFCs) are the most harmful to the ozone layer with the highest ozone depletion potential. CFCs stability allows them to travel to the stratosphere and release chlorine atoms that catalyze the destruction of ozone molecules. The Montreal Protocol has helped reduce CFCs' use, and alternatives like HFCs and HCFCs are less harmful.
Step-by-step explanation:
The compounds that are the most damaging to the stratospheric ozone layer and have the highest ozone depletion potential rating are Chlorofluorocarbons (CFCs). CFC molecules consist of chlorine, fluorine, and carbon atoms and are extremely stable. Their stability allows them to make their way into the stratosphere, where they are broken down by ultraviolet (UV) radiation, releasing Cl atoms. These Cl atoms act as catalysts in the destruction of ozone molecules. A single chlorine atom can destroy ozone molecules for up to two years, contributing to ozone depletion for a significant period. CFCs have been widely used in refrigerants, air conditioning systems, foams, and aerosols.
The Montreal Protocol is an international agreement that has effectively reduced the production and use of CFCs. Alternatives like Hydrofluorocarbons (HFCs) and Hydrochlorofluorocarbons (HCFCs) are being used as they do not contain chlorine or bromine, which can form radicals responsible for ozone depletion. Nevertheless, HCFCs break down more readily in the troposphere and hence are less harmful to the stratosphere.