How do sulfur dioxide (SO2) and nitrogen oxides (NOx) contribute to acid deposition, and what are two environmental effects?

How do sulfur dioxide (SO2) and nitrogen oxides (NOx) contribute to acid deposition, and what are two environmental effects?

• A. SO2 and NOx neutralize rain acidity.
• B. SO2 and NOx are not involved in acid deposition.
• C. SO2 and NOx form sulfuric and nitric acids in the atmosphere; deposition lowers pH of rain and waters; effects include acidification of lakes/streams and soils, and damage to forests and aquatic life.
• D. Acid deposition only affects urban air, not environmental ecosystems.

Answer: (C)

The main idea is that sulfur dioxide and nitrogen oxides from burning fossil fuels react in the atmosphere to form sulfuric and nitric acids. These acids dissolve in atmospheric moisture and return to Earth as acid rain or as dry acidic particles, lowering the pH of rain and surface waters. The two environmental effects highlighted are the acidification of lakes and streams and soils, which disrupts nutrient availability and can mobilize toxic metals, and the damage this acidity can cause to forests and aquatic life, stressing organisms and altering ecosystems. Other choices miss the fact that these gases actually drive acidity, not neutralize it, and that acid deposition affects ecosystems beyond urban areas.

The main idea is that sulfur dioxide and nitrogen oxides from burning fossil fuels react in the atmosphere to form sulfuric and nitric acids. These acids dissolve in atmospheric moisture and return to Earth as acid rain or as dry acidic particles, lowering the pH of rain and surface waters. The two environmental effects highlighted are the acidification of lakes and streams and soils, which disrupts nutrient availability and can mobilize toxic metals, and the damage this acidity can cause to forests and aquatic life, stressing organisms and altering ecosystems. Other choices miss the fact that these gases actually drive acidity, not neutralize it, and that acid deposition affects ecosystems beyond urban areas.