Weathering Wood
Dana Hogan
Grade 9
1
Problem
How is wood effected by varying environmental
solutions?
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2
Research
According to dictionary.com, weathering is to discolor, disintegrate, or affect
injuriously, as by the effects of weather
Acid Rain: a form of precipitation containing high amounts of nitric or sulfuric acid
 Causes: emissions from fossil fuels, vegetation decay, and volcanoes
How acid rain is formed:
 Sulfur dioxide and nitrogen oxide join with compounds in the air, creating
sulfuric and nitric acids
Acid rain is a secondary air pollutant
 Secondary air pollutants formed when several primary pollutants (pollutants that
are emitted directly into the atmosphere such as carbon monoxide from
vehicles) react with one another
Acid rain has very damaging effects on forests, taking nutrients from the soil and
harming branches and needles of trees.
Bacteria break down compounds around them in order to gain energy
 This is a key part to the carbon cycle because without this the carbon from
organic materials would remain trapped underground
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3
Hypothesis
If the wood is placed in the varying environmental solutions, then
the acid rain will weaken the wood the most.
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4
Materials
20 wood samples
75mL distilled water
.6g salt
15mL sulfuric acid
30g soil
pH paper
20 Petri dishes
Force meter
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5
Procedure
1.
4 pieces of wood placed in empty container
2.
4 pieces of wood placed in 30mL distilled water (rain)
3.
4 pieces of wood placed in 30mL distilled water and .6g salt (salt water)
4.
4 pieces of wood placed in 15mL distilled water and 15mL sulfuric acid (acid
rain)
5.
4 pieces of wood placed in 30g soil (soil)
6.
pH balanced of each solution tested
7.
All wood samples left in sealed containers for 18days
8.
Strength of wood samples tested
6
Variables
Independent variable: environmental solution wood
samples are in
Dependent variable: strength of wood
Control: 4 pieces of wood in empty containers
Constants: size and type of wood samples, size of
Petri dish, area of testing
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Quantitative Data
Newtons of Force Required to Break Wood Samples
30
Average Force (N)
25
20
15
10
5
0
Control
Rain
Salt Water
Environmental Solution
8
Soil
Acid Rain
Quantitative Data
Solution of Wood Sample
Average Newtons Needed to Break Wood Sample
Control
23.33
Rain
12.76
Salt Water
10.09
Soil
Acid Rain
Solution of Wood Sample
Control
Rain
Salt Water
9.6
5.47
Standard Deviation
2.13
3.4
0.28
Soil
2.1
Acid Rain
0.6
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Qualitative Data
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Wood samples in acid rain appeared discolored
(beige/pink color)
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Wood samples in salt water and the salt water itself had a
brown, gooey mold
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Wood samples in rain appeared slightly yellowed
Wood samples in soil appeared unaffected
Soil was drier than when the wood samples were placed
in it
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Conclusion
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Acid rain eroded the wood samples the most
Soil had the 2nd greatest weakening effect
Salt water had the 3rd greatest weakening effect
Rain eroded the wood samples the least
The hypothesis that if the wood was placed in the varying
environmental solutions, then the acid rain would weaken the
most was accepted
11
Thanks
“Acid Rain.” NationalGeographic.com. National Geographic, n.d. Web. 11 Oct. 2010. <http://environment.nationalgeographic.com/global-warming/acid-rainoverview>.
“The Effects if Environmental Factors on Wood Decay.” All-Scince-Fair-Projects.com. N.p., Aug. 2002. Web. 11 Oct. 2010. <http://www.all-science-fairprojects.com/project1224_108_1.html>.
“Variables in Your Science Fair Project.” Sciencebuddies.com. N.p., n.d. Web. 11 Oct. 2010. <http://www.sciencebuddies.org/science-fairprojects/project_variables.shtml>.
“What is Acid Rain?” epa.gov. U.S. Environmental Protection Agency, 8 June 2007. Web. 11 Oct. 2010. <http://www.epa.gov/acidrain/what/>.
Winkler, Robert. “Is Acid Rain Killing Off Wood Thrushes?” NationalGeographic.com. National Geographic, n.d. Web. 11 Oct. 2010.
<http://news.nationalgeographic.com/news/2002/08/0813_020813_acidrain.html>.
Maczulak, Anne. "hazards in the air." Science Online. Facts On File, Inc. Web. 14 Feb. 2011.
<http://www.fofweb.com/activelink2.asp?ItemID=WE40&SID=5&iPin=GTP0005&SingleRecord=True>.
"Decomposition of Organic Matter." Library.ThinkQuest.org. N.p., n.d. Web. 6
Dec. 2010. <http://library.thinkquest.org/11226/main/c17txt.htm>.
"Weathering." Dictionary.com. Dictionary.com LLC, 2011. Web. 6 Dec. 2010.
<http://dictionary.reference.com/browse/weathering>.
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Thanks
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Thank you for listening.
Questions?
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