______ is a primary cause of acid rain.

______ is a primary cause of acid rain.

• A. Nitrogen oxide
• B. Carbon monoxide
• C. Ozone
• D. Sulfur dioxide

Answer: (D)

Acid rain forms when certain air pollutants react with moisture in the atmosphere to create acids that fall with precipitation. The main culprits are sulfur dioxide and nitrogen oxides produced by burning fossil fuels. Sulfur dioxide is the primary driver because it is released in large quantities from coal and oil combustion and readily oxidizes to sulfur trioxide, which combines with water to form sulfuric acid. This acid significantly lowers the pH of rain. Nitrogen oxides also contribute by forming nitric acid, but the overall acidification of rain is most strongly linked to sulfur dioxide emissions from power plants and industry. Carbon monoxide doesn’t form acidic compounds in rain, and ozone is a pollutant that causes smog-related effects rather than directly creating acidic precipitation.

Acid rain forms when certain air pollutants react with moisture in the atmosphere to create acids that fall with precipitation. The main culprits are sulfur dioxide and nitrogen oxides produced by burning fossil fuels. Sulfur dioxide is the primary driver because it is released in large quantities from coal and oil combustion and readily oxidizes to sulfur trioxide, which combines with water to form sulfuric acid. This acid significantly lowers the pH of rain. Nitrogen oxides also contribute by forming nitric acid, but the overall acidification of rain is most strongly linked to sulfur dioxide emissions from power plants and industry. Carbon monoxide doesn’t form acidic compounds in rain, and ozone is a pollutant that causes smog-related effects rather than directly creating acidic precipitation.