Acid rain occurs when sulfur dioxide and nitrogen oxides are released into the atmosphere and later fall to the ground as rain, snow, or other precipitation with a pH lower than 5.6. Normal rain has a pH of around 5.6, but the most acidic rain in the US in 2000 had a pH of 4.3. Acid rain is caused by emissions from fossil fuel combustion and natural sources like decaying plant matter. The Clean Air Act of 1990 was passed to reduce sulfur dioxide and nitrogen oxide emissions to control acid rain levels. High elevation forests are more damaged by acid rain than lower elevation forests. The term "acid rain" was first used by British chemist Robert Angus Smith in the 1800s.

2. 1. All rainwater contains
some level of acidity.
The pH scale measures the amount of acid in a
substance.
Normal rainwater has a pH of 5.6
The reason why this is, is because normal rainwater
contains carbon dioxide.
“As of 2000, the most acidic rain falling in the U.S.
has a pH of about 4.3.”
(Measuring Acid Rain)

3. 2. The chemicals that
produce acid rain can be
released by dying and
rotting plant life
(Acid Rain Facts)

4. 3. In 1990, Congress passed
the Clean Air Act which is now
known as the Acid Rain
Program to reduce as well as
control the levels of Sulfur
Dioxide and Nitrogen Oxides in
the atmosphere
(Facts about Acid Rain)

5. 4. The forest at higher
elevations are damaged
more than those who are
not
(Acid Rain Facts - All Amazing Facts)

6. 5. The term acid rain was
first used by a chemist
named Robert Angus
Smith
(2008, Acid Rain)

7. Works Cited
2008, "Acid Rain." The Environment: A Revolution in
Attitudes.,
Haeuber, Haeuber, Richard, "Acid Rain." UXL
Encyclopedia of
Science. 2002, "Acid Rain." World of
Earth Science. 2003,
Lippmann, Lippmann, Morton, "Acid Rain." Dictionary of American
History. 2003,
Sharpe, William E., "acid Rain." The Columbia
Encyclopedia, 6th Ed.. 2013, "acid Rain." A Dictionary of
Biology. 2004, Chappelka, Arthur H., "acid Rain." World
Encyclopedia. 2005, AILSA ALLABY;MICHAEL ALLABY,
"acid Rain." The Oxford Pocket Dictionary of Current English.
2009, and MICHAEL ALLABY. "Acid Rain." Encyclopedia.com.
HighBeam Research, 01 Jan. 2008. Web. 15 Nov. 2013.
"Acid Rain Facts - All Amazing Facts." Acid Rain Facts - All Amazing
Facts. N.p., n.d. Web. 15 Nov. 2013.
"Acid Rain Facts." Acid Rain Facts. N.p., n.d. Web. 15 Nov. 2013.
"Facts about Acid Rain." Interesting Facts. N.p., 10 Jan. 2013. Web.
15 Nov. 2013.
"Measuring Acid Rain." EPA. Environmental Protection Agency, 4
Dec. 2012. Web. 15 Nov. 2013.