Which of the following chemicals is a major contributor to ozone layer destruction?

• A. Carbon dioxide (CO_2)
• B. Methane (CH_4)
• C. Chlorofluorocarbons (CFCs)
• D. Nitrogen gas (N_2)

Answer: (C)

Verified step by step guidance

1. Understand that the ozone layer is a region in the Earth's stratosphere that contains a high concentration of ozone (O_3) molecules, which protect life by absorbing most of the Sun's harmful ultraviolet (UV) radiation.
2. Recognize that certain chemicals can cause the breakdown of ozone molecules, leading to ozone layer depletion. These chemicals are often stable in the lower atmosphere but release reactive species in the stratosphere.
3. Identify that Chlorofluorocarbons (CFCs) are compounds containing chlorine, fluorine, and carbon atoms. When CFCs reach the stratosphere, UV radiation breaks them down, releasing chlorine atoms.
4. Know that chlorine atoms act as catalysts in the destruction of ozone by reacting with ozone molecules (O_3) to form chlorine monoxide (ClO) and oxygen (O_2), and then regenerating chlorine atoms to continue the cycle.
5. Compare the other options: Carbon dioxide (CO_2) and methane (CH_4) are greenhouse gases but do not directly destroy ozone, and nitrogen gas (N_2) is inert in this context. Therefore, CFCs are the major contributors to ozone layer destruction.