Acid rain affects soils, waterways, and forests by:

• A. Acid rain raises soil pH and reduces metal mobility
• B. Acid rain lowers soil pH but does not affect waterways
• C. Acid rain lowers pH and mobilizes metals, harming vegetation and aquatic life
• D. Acid rain neutralizes soil acidity

Answer: (C)

Acid rain introduces extra hydrogen ions into soils and water, lowering their pH. That increased acidity causes base cations like calcium and magnesium to be leached from the soil, reducing the soil’s buffering capacity. As pH drops, metals such as aluminum become more soluble and mobile, which can be toxic to plants by damaging root tissues and disrupting nutrient uptake. In forests, this weakens trees, stresses growth, and can alter nutrient balance in the soil. In waterways, lower pH and higher dissolved metals harm aquatic life, affecting respiration, reproduction, and overall ecosystem health. So the overall effect is a lowering of pH plus mobilization of metals, leading to harm for vegetation and aquatic organisms.