DEAR CANDITATE,

Acid rain results when Sulfur dioxide (SO ₂ ) and nitrogen oxides (NO _X ) are emitted into the atmosphere and transported by wind and air currents. The SO ₂ and NO _X react with water, oxygen and other chemicals to form sulfuric and nitric acids. These then mix with water and other materials before falling to the ground. It can have harmful effects on plants, aquatic animals, and infrastructure.

Acid rain, or acid deposition, is a broad term that includes any form of precipitation with acidic components, such as sulfuric or nitric acid that fall to the ground from the atmosphere in wet or dry forms.  This can include rain, snow, fog, hail or even dust that is acidic.

• Burning of fossil fuels to generate electricity.  Two thirds of SO ₂ and one fourth of NO _X in the atmosphere come from electric power generators.
• Vehicles and heavy equipment.
• Manufacturing, oil refineries and other industries.

Winds can blow SO ₂ and NO _X over long distances and across borders making acid rain a problem for everyone and not just those who live close to these sources.

Processes involved in acid deposition (only SO ₂ and NO _x play a significant role in acid.

Hope it is useful.