How do sulfur dioxide (SO2) and nitrogen oxides (NOx) from burning fossil fuels contribute to acid rain?

• A. They neutralize acidic rainfall, making rain less acidic.
• B. They oxidize to form sulfuric and nitric acids that deposit as acid rain.
• C. They have no impact on rain acidity.
• D. They only affect air quality and not precipitation.

Answer: (B)

The main idea here is that emissions from burning fossil fuels create pollutants that transform in the atmosphere into acidic compounds, which then fall with rain. Sulfur dioxide is oxidized in the air to sulfur trioxide and then rapidly combines with water to form sulfuric acid. Nitrogen oxides react with atmospheric oxidants like hydroxyl radicals to form nitric acid. These acids dissolve in rain droplets, producing rain that is more acidic than normal. This process can happen over long distances, so areas far from the original pollution can experience acid rain. That’s why the correct explanation is that these pollutants oxidize to form sulfuric and nitric acids that deposit as acid rain. The other statements don’t fit because they either claim neutralization, no effect on rain, or that only air quality is impacted, which doesn’t describe the acidic precipitation mechanism.