Question

Consider the following statements:

1. Methane is both a natural and anthropogenic pollutant.

2. It is primarily responsible for photochemical smog formation.

3. It is the most abundant hydrocarbon in the atmosphere.

Which of the statements is/are correct?

• A. 1 and 2 only
• B. 1 and 3 only
• C. 2 and 3 only
• D. All of the above

Answer 1

Answer:

B. 1 and 3 only

• Correct Answer: Option B) 1 and 3 only

• Methane is both a natural and anthropogenic pollutant.

• This statement is correct. Methane is produced naturally through processes like wetland emissions, termite activity, and release from oceans. It is also produced through anthropogenic (human) activities including agriculture (rice cultivation, livestock), fossil fuel extraction, landfills, and biomass burning.

• It is primarily responsible for photochemical smog formation.

• This statement is incorrect. Photochemical smog is primarily formed from nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. The main contributors are vehicle emissions and industrial processes. While methane is a VOC, it is not the primary contributor to photochemical smog formation.

• It is the most abundant hydrocarbon in the atmosphere.

• This statement is correct. Methane (CH₄) is indeed the most abundant hydrocarbon (compounds consisting of hydrogen and carbon) in Earth's atmosphere, with a concentration of approximately 1.8-1.9 parts per million.