When chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants decompose in the atmosphere, which gas is primarily released that contributes to ozone depletion?

• A. CO_2 (carbon dioxide)
• B. O_2 (oxygen gas)
• C. Cl (chlorine atoms)
• D. Cl_2 (chlorine gas)

Answer: (C)

Verified step by step guidance

1. Understand that chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are compounds containing chlorine, fluorine, carbon, and sometimes hydrogen atoms.
2. Recognize that when CFCs and HCFCs reach the stratosphere, they are broken down by ultraviolet (UV) radiation from the sun, causing the release of chlorine atoms.
3. Know that the chlorine atoms (Cl) released are highly reactive and catalyze the breakdown of ozone (O_3) molecules, leading to ozone depletion.
4. Distinguish between chlorine atoms (Cl) and molecular chlorine gas (Cl_2); the reactive species responsible for ozone depletion is the chlorine atom, not the chlorine gas.
5. Conclude that the primary gas released from the decomposition of CFCs and HCFCs that contributes to ozone depletion is the chlorine atom (Cl).