What specific chemical process leads to the depletion of stratospheric ozone by chlorofluorocarbons (CFCs)?

The specific chemical process that leads to the depletion of stratospheric ozone by chlorofluorocarbons (CFCs) is catalytic destruction. CFCs are stable, man-made chemicals that were widely used as refrigerants, propellants, and solvents. Once released into the atmosphere, CFCs can persist for decades, slowly diffusing into the stratosphere. In the stratosphere, CFCs are broken down by ultraviolet (UV) radiation from the sun, releasing chlorine atoms (Cl). The chlorine atoms act as catalysts, meaning they facilitate a chemical reaction without being consumed in the process. A single chlorine atom can destroy thousands of ozone molecules through a chain reaction. The process begins when a chlorine atom reacts with an ozone molecule (O3), forming chlorine monoxide (ClO) and molecular oxygen (O2): Cl + O3 -> ClO + O2. Next, the chlorine monoxide molecule reacts with another oxygen atom (O), releasing the chlorine atom and forming molecular oxygen: ClO + O -> Cl + O2. The chlorine atom is then free to react with another ozone molecule, repeating the cycle. This catalytic cycle continues until the chlorine atom is eventually removed from the stratosphere by other chemical reactions. However, during its time in the stratosphere, a single chlorine atom can destroy a large number of ozone molecules, leading to significant ozone depletion. The depletion of the ozone layer, which absorbs harmful UV radiation from the sun, increases the amount of UV radiation reaching the Earth's surface, which can cause skin cancer, cataracts, and other health problems, as well as damage ecosystems.