An acid is a substance distinguished by its ability to react with a base (Acid Rain and The Facts 2005). This form of precipitation is named acid rain is because it has a high acidity according to the pH scale. The pH scale is a system of measurement to measure “the amount of acid in a liquid-like water.” Acids release hydrogen ions, and the acid content of a solution is based on the concentration of hydrogen ions and therefore shown as pH (Acid Rain Encyclopedia Britannica 2005). The pH scale ranges from 0 to 14 with 0 being the maximum acidity and 14 being maximum alkalinity. A pH of 7 is considered to be neutral. When rain that falls is considered to be 5.5 or lower on the pH scale, then it is considered to be acidic (Acid Rain Britannica Student Encyclopedia 2005).
Two main causes of acid rain are sulfur dioxide and nitrogen oxide. Sulfur dioxide is formed by industrial processes, which burn fossil fuels. The main contributors are ore smelting, coal-fired power generators, and natural gas processing. Nitrogen oxide is discharged into the atmosphere through the combustion of fuels from automobiles, furnaces, and industrial and electrical boilers and