What is acid rain and why is it harmful?

• A. Rain made acidic by pollutants; it damages ecosystems and buildings.
• B. Rain that has a pleasant taste and smell.
• C. Rain that helps plant growth by adding nutrients.
• D. Rain that only occurs in deserts.

Answer: (A)

Acid rain is rain that has become more acidic because pollutants released into the air, mainly sulfur dioxide and nitrogen oxides from burning fossil fuels, dissolve in clouds and form acids such as sulfuric and nitric acid. This extra acidity lowers the pH of rainfall. It harms by acidifying lakes and rivers, which can damage or kill aquatic life, and by leaching essential nutrients from soils, making it harder for plants to grow. It also accelerates the corrosion of buildings and statues made from materials like limestone and marble. The other descriptions don’t fit because rain that tastes or smells pleasant, or that supposedly provides nutrients, or rainfall that only occurs in deserts, does not describe acid rain.