Environmental Science
Name: ______________________________
Air
Section Goal: The student will explain the causes of acid precipitation, explain how acid precipitation affects
plants, soils, and aquatic ecosystems, describe three ways that acid precipitation affects humans and describe
ways that countries are working together to solve the problem of acid precipitation.
Vocabulary:
1. acid precipitation
2. pH
3. acid shock
Notes: Chapter 6.3: Acid Precipitation
 Suppose that one day you are hiking in the woods. You come to a ____________ and sit down to rest.
You are looking at the lake, amazed at how _______________the water is, and then you realize
something is _____________________. You realize there are __________ fish in the water.
What Causes Acid Precipitation
 This lake and thousands of lakes throughout the ________________ are victims of acid precipitation,
also known as __________________________________.
 Acid precipitation is rain, sleet or snow that contains a __________________ concentration of acids.
 When ___________________ fuels are burned, they _________________oxides of sulfur and nitrogen;
when combined with _______________in the atmosphere, they form sulfuric acid and nitric acid
 Acid precipitation falls to Earth, flows over the land, into the lakes, rivers and streams
________________________ living things (both plant and animal)
 A ____________ (power of hydrogen) number is a measure of how _________________ or
____________________ a substance is
 The _______________ the pH, the ________________ acidic a substance is; the ________________the
pH number is, the more ____________________ the substance is; each whole number on the pH scale
indicates a _________________________change in acidity
 Pure water has a pH of ________________; normal precipitation has a pH of ________________; water
is considered acid precipitation if it has a pH below _________________
 pH of precipitation _____________________ between locations: Scandinavia ranges between 4.3 to
4.5; Europe between 4.5 and 5.1; eastern US and Canada ranges between 4.2 and 4.8
 The most acidic precipitation in North America occurs around ___________________________ and
Lake Ontario; pH levels are about ______________
How Acid Precipitation Affects Soils and Plants
 Plants adapt over ______________ periods of time to the acidity of the soil they grow in; acid
precipitation can cause a drop in soil and water pH; this increase is call __________________________
 Acidification changes the balance of soil’s ______________________; some nutrients are dissolved and
washed away, ___________________________ and other toxic metals may be released and absorbed by
roots of plants (root damage); sulfur dioxide __________________ the openings on the surface of plants
Acid Precipitation and Aquatic Ecosystems
 Aquatic animals are _______________________ to live in water with specific pH levels; if acid rain
falls on a lake, it can change the pH level, thus ______________________ aquatic plants, animals and
fish. Aluminum can also ___________________ out of the soil surrounding the lake, accumulating in
the gills of the fish, which interferes with the oxygen and salt _______________________.


Worse in the ________________________ when snow melts; creates acid shock (rapid change in
water’s pH) which results in a large number of _________________ dying; also affects the reproduction
of fish and amphibians (produce fewer eggs which oftentimes don’t even ________________; offspring
that do ______________________ may have birth defects and cannot reproduce)
To offset the effects of acid rain, some place in the US and other countries will spray powdered
________________on the lakes to help ______________________ the natural pH of the water
Acid Precipitation and Humans
 Acid precipitation can affect ________________________ in a variety of ways
 _____________________ metals (aluminum and mercury) can be released into the soil and find their
way into crops, water and fish which are then eaten by humans
 Researchers believe there may be a _______________________________ between acid precipitation
and respiratory problems, especially in _____________________
 Standard of ________________________ of some peoples is affected: commercial fisherman, sport
fishing industries, forestry
 Acid precipitation destroys ___________________ and historic __________________________
International Conflict and Cooperation
 One big problem in controlling acid precipitation is that ______________________ may be released in
one geographic location and ________________to the ground in another location (ex: ½ of the acid rain
falling in southeastern Canada results from pollution produced in Ohio, Indiana, Pennsylvania, Illinois,
Missouri, West Virginia and Tennessee
 Very difficult to solve since acid precipitation falls ______________________ (Canada-US Air Quality
Agreement was signed in 1991); both countries agreed to ___________________ acidic emissions that
flowed across the border.
Lesson Reflection:
Use page 162 to complete The pH Scale handout.
Assessment:
1. Explain how acid precipitation forms.
2. Describe the harmful effects that acid precipitation can have on plants, soils and aquatic ecosystems.
3. Describe three ways in which acid precipitation can affect humans.
4. Describe a way in which countries are working together to solve the problem of acid precipitation.
Active Reading: Acid Precipitation
Lesson extension (Technology/Application/Connection to real-world): POSTER
Effects of Acid Precipitation on tombstones, buildings and statues poster (Group or Individual Activity)
Students will create a poster after research and include the following information:
1. Select tombstones, a specific building or a particular statue. Document findings with pictures
2. What actions are being taken to protect the structure you choose?
3. What is being done to guard against future damage?