The National Student Research Center
E-Journal of Student Research: Science
Volume 7, Number 2, March, 1999
The National Student Research Center is dedicated to promoting student research and the use of the scientific method in all subject areas across the curriculum, especially science and math.
For more information contact:
- John I. Swang, Ph.D.
- Founder/Director
- National Student Research Center
- 2024 Livingston Street
- Mandeville, Louisiana 70448
- U.S.A.
- E-Mail: nsrcmms@communique.net
- http://youth.net/nsrc/nsrc.html
TABLE OF CONTENTS
- Do Different SPF's Make A Difference When Using Same Brand Sunblock? Does Price Affect The Way Sunblock Works?
- Viscosity
- The Growing Of Plants Under Different Colored Lights
- How Humidity Affects The Growth Of Cherries
- The Flammability Of Household Fabrics
- Which Household Items Lubricate Metal The Best?
- Root Development
- The Decomposition Of Different Foods In Different Environments
- The Effect Of pH On The Life Span Of A Tadpole
- Mouthwash And Bacteria
Title: Do Different SPF's Make A Difference When Using Same
Brand Sunblock? Does Price Affect The Way Sunblock
Works?
Student Researcher: Laura Barkin
School: Edgemont Jr/Sr. High School
White Oak Lane
Scarsdale New York 10583
Grade: 7
Teacher: Ms. Russo
I. Statement of Purpose and Hypothesis:
I wanted to know if SPF matters when you buy sun block. For
example, does a CVS brand 30 sunblock work better than a CVS
brand 15 sunblock? I also wanted to know if higher priced
sunblock works better than lower priced sunblock of the same
SPF? My hypothesis was that the higher the SPF the better it
would protect and that higher priced sun block would work better
than lower priced.
II. Methodology:
For the first part of my project, I bought four types of CVS
brand sunblock. Each of these sunblocks had a different SPF.
The different SPF's were 30, 15, 8, and 4. I also bought a pack
of developing paper at a local photography store and 4 clear
plastic report folders. I then got some distilled water and a
dish pan. I asked my science teacher for sodium thiosulfate.
The first thing I did was divide the report folder in 4 equal
squares using masking tape. I then labeled each sun block 1, 2,
3, or 4. I labeled each square 1, 2, 3, or 4. I then applied
the numbered sunblock to the appropriate square. I put the same
amount of sunblock on each square making it as even as possible.
After I put the sunblock on, I dimmed the lights very low. I
carefully took out a piece of developing paper, making sure to
close the case afterwards to keep the light away from the other
sheets. I put the developing paper, glossy side up, inside the
report. I then quickly took it outside on the driveway where it
was very sunny. I left it there for exactly 5 minutes. While
it was in the sun I made the mixture of the sodium thiosulfate
and distilled water in the dish pan. When the 5 minutes was up
I brought the report folder back inside to the semi-darkened
room. There I carefully took out the developing paper from the
report folder and layed it glossy side down in the mixture for
three seconds. Then I immediately rinsed it with cold water and
let it dry for 15 minutes. When it was dry I observed it.
For the second part of my experiment I did the exact same thing
except I used the sun blocks that varied in price, but had the
same SPF.
My controlled variables was that I used the same amount of light,
same dish pan, and the same mixture of sodium thiosulfate. My
manipulated variables were the different sunblocks with the
different SPF's or the differently priced sunblock. The responding
variable were my results.
III. Analysis of Data:
On the developing paper, the sunblock which allowed the least
amount of sun to penetrate, turned the whitest. When I observed
the data from my first experiment I was very surprised at what I
saw. I noticed that the SPF 30 sunblock was darker than the SPF
4 sunblock. This was very strange because I surely thought that
30 was better than 4. What I then saw was that in some places I
had put more sunblock on the number 4 square than others, also
the places where I had put more sunblock were the lightest and
where I hadn't put much on it was the darkest. For trial one
SPF 4 was the best, then SPF 8, then SPF 15, and last SPF 30.
For trial two, SPF 8 was the best, then SPF 4, then SPF 15, and
last SPF 30.
For the second part of the project my results were not as
strange, but were not what I expected. For trial one, "Bain de
Soliel", which was the highest priced, worked the best. "Banana
Boat", which was the least expensive, was second. "Bio Sun",
the second highest priced was next, and then the second lowest
priced, "Neutrogena" came in last.
IV. Summary and Conclusion:
As I said before, I was very surprised when I saw the results of
both tests. They did not agree with my hypothesis at all. For
the first experiment, it seemed to me that it did not matter
what SPF you used, but how much you put on of each one. That is
why I think SPF is irrelevant, if you put a lot of sunblock on
and keep reapplying it.
For my second experiment, I think it mattered how thick the
sunblock was. Bain de Soliel was the thickest and then Banana
Boat. But Neutrogena which came last was not thick and was very
light. So, for my second experiment, I feel price does not
matter, but thickness does.
V. Application:
I can apply the results of this experiment in many ways to my
life now. I now know I can use any type of sunblock and the SPF
will not matter. I will just have to remember to put a lot on
and keep reapplying it. I also know that if I buy a sunblock
and it has a thin texture to find another brand. These results
can be critical for many people. With the depletion of our
ozone layer, skin cancer is a common problem. People need to be
aware of the SPF confusion and be informed about thick
application of sunblock to prevent the damaging effects of the
sun.
Title: Viscosity
Student Researcher: Caitlin Dieck
School: Fox Lane Middle School
RT 172
Bedford, New York 10506
Grade: 6
Teacher: Carolynn Sears, Ph. D.
I. Statement of Purpose
The purpose of my experiment was to find out if the name brand
or temperature of olive oil effects its viscosity. My first
hypothesis stated that the Pope Delicato and Candoni (Extra
Virgin) will be most viscous. My second hypothesis stated that
cold olive oil will be more viscous than warmer olive oil.
II. Methodology
I designed two experiments to test my hypotheses. The materials
I needed for the experiments were a stopwatch, a paper clip, a
measuring cup, 4 types of olive oil, a microwave, a magnet, and
a bottle.
The first experiment is called the Pour Test. My mom would set
the bottle on the ramp to let the olive oil pour into the
measuring cup. I would be next to her timing how long it took
to pour to the 1 cup line. We would do this with all four
brands/types at the different temperatures. We would pour each
oil three times and then average the times.
The controlled variable is the size of the measuring cup. The
manipulated variables are the temperature of the olive oil and
the different brands of olive oil. The dependent variable is
the time it takes for 1 cup of olive oil to pour.
The second test was called the Paper Clip Test. I would take
the paperclip, put it in the olive oil, then take the magnet and
pull the paperclip right above the olive oil, and then release
the paperclip. My mom would stand next to me and time how long
it took to touch the bottom of the bottle. We would do this in
all the brands/types in the different temperatures. We would
drop the paper clip three times to get an average.
The controlled variables were the size of the paper clip and the
measuring cup, and how the paper clip is dropped. The
manipulated variables were the temperature of the olive oils and
the different brands. The dependent variable is the time for
the paper clip to drop through the olive oil.
III. Data Analysis
The data showed that the extra virgin olive oils (purer olive
oils) were generally more viscous and that cold olive oil was
generally more viscous.
IV. Conclusion
In my conclusion, the Candoni (Extra Virgin) and Pope (Extra
Virgin) are most viscous. Candoni (Extra Virgin) was most
expensive, then came Pope (Extra Virgin). Out of the
temperatures, the cold olive oils were most viscous in most of
my data. In my hypothesis, I thought that the Pope Delicato and
Candoni (Extra Virgin) were going to be most viscous, but I was
wrong.
V. Application
From doing this experiment, I found that Candoni (Extra Virgin)
and Pope (Extra Virgin) are most viscous and that cold olive oil
is more viscous than hot olive oil. I have also learned more
about graphing and organizing my data. I learned a lot. One
thing I will remember is to let the olive oil become room
temperature before pouring it for cooking.
Title: The Growing Of Plants Under Different Colored Lights
Student Researcher: Thomas McConville
School Address: Fox Lane Middle School
Route 172
Bedford New York 10506
Grade: 6
Teacher: Dr. Sears and Mr. Karlsson
I. Statement of Purpose and Hypothesis
I wanted to find out whether the color of the light source has
an effect on the growth of plants. My hypothesis was that
regular white light from a regular light bulb would be the most
effective light source on the plant. The other two colors in my
experiment were red from one end of the spectrum and green from
the other end of the spectrum.
II. Methodology
I purchased radish seeds because they grow very quickly. Then I
gathered my materials which were: three light bulbs, (red,
green, and white), 20 seeds, four pots exactly the same size,
potting soil, three lamps. I placed one plant in the sun
(natural light), and this was my control. The different colored
lights were the independent variable. The controlled variables
were: the same brand of lamps, the distance of the lights from
the plants I grew, the temperature and amount of water, the
amount of soil, the pot size, the depth that the seeds were
planted. The plants were placed in a closet with the same
temperature, and each plant received the same amount of light
(same watt bulb). The dependent variable was the amount that
the plants grew under the different colored lights. Once I
gathered all of my materials, I planted the seeds the same depth
in the same size pot and the same amount, and kind of potting
soil. I watered with the same amount and temperature of water
to begin this experiment. I watered my plants every other day.
I placed the three pots in a dark closet, with the different
colored lights above them at the same distance. I turned on the
light sources for twelve hours each day. I watched every day to
see which plant grew the fastest. I measured the length of the
stem and took observations of this experiment. I also took
pictures of this experiment.
III. Analysis of Data
My hypothesis proved to be correct: the white (or clear bulb)
proved to be the best light source. The next tallest was the
plant under the red bulb. The next tallest was the plant under
the green bulb and the last was the plant growing in natural
light. However, the plants in the natural light were the
healthiest and had the largest leaves.
IV. Summary and Conclusion
I found out that clear or white light grew the tallest plants.
Their leaves were also full. This probably happened because
there was twelve hours of continuous light per day. Although
the red and green plants were the next tallest, they were not as
healthy looking. The plants under the natural light were not as
tall, but had very full leaves and looked the healthiest. My
hypothesis was correct.
V. Application
Although natural light may not grow plants as fast, they will
turn out to be healthier. My second choice for growing plants
would be a regular white light left on for at least 12 hours per
day.
Title: How Humidity Affects The Growth Of Cherries
Student Name: Michael Kistenmacher
School Address: Edgemont Jr./Sr. High School
White Oak Lane
Scarsdale, NY 10583
Grade: 7
Teacher: Ms. Russo
I. Statement and Purpose and Hypothesis:
My hypothesis states that if cherry branches are covered in a
transparent plastic bag and are allowed to accumulate humidity,
the percentage of blossoms that become cherries will be higher
on the covered branches than on the uncovered branches.
II. Methodology:
I selected, in May 1998, four branches of a cherry tree in my
garden. Over the first and third branch, I put a transparent
plastic bag. I counted the blossoms on each of the branches and
also recorded the percentage of blossoms that became cherries.
In addition, I recorded the high and low temperature every day.
I recorded these temperatures in order to know if there was a
frost or excessive heat, that could have affected the growth of
the cherries. Sometimes I took pictures of the branches. Inside
of the plastic bag there were always water drops and that
explains the high humidity inside. Sometimes I had to remove
water from the plastic because it was too humid inside. If I
would have left the water there, mold could be produced inside.
III. Analysis of Data:
I recorded the data every day and wrote them on a data table.
From that data, I generated two charts of the percentage of the
blossoms that turned into cherries and another one just for the
amount of the cherries. I also checked the temperature in order
to know if there was excessive heat or frost that could affect
the cherries. The maximum temperature was 34.4 C and the low
was 2 C. Therefore there was no negative temperature effect on
the cherries.
IV. Summary and Conclusion:
The data show that between 10 and 2S percent of all the blossoms
turned into cherries in the first weeks. The uncovered blossoms
had totally different results then the covered blossoms. The
second branch (uncovered) grew fast, but the fourth (uncovered)
branch lost it's blossoms. The blossoms of the branches one and
three (covered) grew fast and did not loose cherries as fast as
the fourth branch did. But, in the end, only 1 to 5 percent of
the cherries remained. There was no advantage for the covered
branches. I conclude that my hypothesis is wrong.
V. Application:
My results show that, in 1998, a cherry farmer did not have to
put a plastic bag around the branches of a cherry tree, because
there was no advantage in doing so, in the New York area.
Because there could be different temperatures in other states or
in other years, the effect of the plastic bag could help to
prevent frost damage. Also, in very dry climates, the humidity
might be useful for the growth of cherries.
Title: The Flammability Of Household Fabrics
Student Researcher: Andrew Laub
School Address: Edgemont Jr./Sr. High School
White Oak Lane
Scarsdale, New York 10583
Grade: 7
Teacher: Ms. Russo
I. Statement of Purpose and Hypothesis:
The purpose of my project is to find out more about the
flammability of household fabrics used in the home, and maybe
find a relationship between the size of the fabric, the length
of time that it was exposed to fire, and the length of time that
it takes to burn. Since I picked out a lot of different kinds
of fabric to test, I wasn't sure of what to expect. My
hypothesis states that most of the fabric would burn (or melt)
rather quickly.
II. Methodology:
I tested my hypothesis through a cycle of using two different
sizes of the same fabric, tested twice.
My controlled variables were the unit measurement of time (in
seconds), and the way the fabric was lighted (by using a match
held directly to the fabric which was folded over to help get
the fire going on all sides). This was done for every single
piece of cloth tested. The responding variable was the time the
fabric took to burn. The manipulated variables were the kinds
of fabrics used and the two different sizes of the fabric (4
in. squares and 16 in. squares).
I used 7 different kinds of fabric: Nylon, Satin Taffeta, Terry
Cloth, Brushed T-Shirt Cotton, Broad Cloth, Linen, and Rayon.
Both the Nylon and the Terry Cloth weren't fully consumed by the
flame at any time in the experiment, I made a special graph for
those two fabrics. One size set of replications was 16 square
inches of cloth per square, and the other, 4 square inches per
square. On our grill, which was lined with aluminum foil, I
would put down one piece of cloth at a time, fold it over, and
light a match to it. The second I touched the match to it, I
started my stopwatch. When the cloth caught on fire, I pressed
the "Laps" button. When either the cloth had smoldered, in
which case I would just give the cloth some more seconds on its
time before stopping the watch, or it had been consumed, I would
press the "Stop" button. I would read the first time that I
recorded, the exposure-before-igniting-time, the burning time,
and the whole time in seconds and record it on to my data chart.
III. Analysis of Data:
The data I collected from my 4 in. square cloth pieces
indicated that Nylon was the fastest to burn, (although Nylon
was never fully consumed), and Linen the slowest. The average
time Nylon took to burn was 38.79 seconds, Satin Taffeta was
41.24 seconds, Terry Cloth was 78.28, Brushed T-Shirt Cotton was
86.43 seconds, Broad Cloth was 46.39, Linen was 133.74 seconds,
and Rayon was 66.87. These are the times for the 4 in. square
pieces of cloth. As for my hypothesis, it was generally proven
wrong by the fact that only 3 groups of cloth burned in under
one minute on average. One of the groups burned on average in
over two minutes.
The data I collected from my 16 in. square cloth pieces
indicated that Satin Taffeta, this time, took the shortest time
to burn; and Linen, again, the longest time to burn. Nylon
averaged to burn in 35.22 seconds, Satin Taffeta in 33.53
seconds, Terry Cloth in 55.81, Brushed T-Shirt Cotton in 103.36
seconds, Broad Cloth in 48.79, Linen in 121.05 seconds, and
Rayon in 76.47. As my hypothesis is concerned, it was, again,
generally proven wrong because only 4 groups of cloth burned in
under one minute on average. The Nylon and the Terry Cloth were
never fully consumed during the project, so that may have caused
numbers to be off and more groups in the 4 in. square group to
have less types of cloth burn in under one minute.
IV. Summary and Conclusion:
I have found out that most fabrics burn moderately fast, but
nothing close to the ones that you might hear about in colonial
stories with women who stand too close to the fire and their
dresses go up in flames in a snap. Most of the cloth burned
slowly. Therefore, I reject my hypothesis because I thought
that most of the fabric would burn quickly, but they burned
moderately fast.
V. Application:
These findings could improve in-home fire safety for many
families by encouraging them to buy, and more stores to use,
linen in their clothing, although it is kind of a weird fabric
for regular clothing. But it could be encouraged to be more
widely used in household fabrics in general for human safety.
It could prevent even the smallest things like table top candle
accidents from spreading all around the house. These are some
ways that my findings can make the world a better place.
Title: Which Household Items Lubricate Metal The Best?
Student Researcher: Mandy Mitchell
School Address: Hillside Middle School
1941 Alamo
Kalamazoo, Michigan 49007
Grade: 7
Teacher: Barbara A. Minar
I. Statement of Purpose and Hypothesis
In my experiment, I planned to find out which household items
lubricated metal the best. Of baby oil, Softsoap, vegetable
oil, and Vaseline, I thought vegetable oil would lubricate metal
the best followed by baby oil, Softsoap, and Vaseline.
II. Methodology
To test my hypothesis, I built a ramp 57.5 cm tall, 13 cm wide,
and 103.5 cm long. This created a 29.5 degree angle from the
surface it sits on and the slanted board. The slanted board was
covered with a very smooth aluminum sheet 1 mm thick. I also
bought a steel block l cm wide, l cm tall, and 14 cm long. Then
I rounded the edges on the corners to make sure there weren't
any burrs. I also gathered distilled white vinegar, Vaseline,
baby oil, vegetable oil, paper towels, a level surface big
enough to set the ramp on, a stopwatch that is accurate to the
hundredth of a second, a 5 ml calibrated container, four
disposable paint brushes, and a permanent marker.
In doing the experiment, the controls were the degree of the
ramp, the surface of the ramp, the positioning of the block, the
amount of the lubricant, the method of timing the block, the
method of cleaning the ramp, the spread of the lubricant, the
type and brand of the paint brushes, and the brands of the
lubricants, vinegar, and paper towels.
To begin, place the ramp on the level surface. Measure out 5 ml
of whatever lubricant you decide to start with. To keep from
confusing them, label the paint brushes with the permanent
marker. Also color one end on one side of the metal block with
the permanent marks. When testing, this part of the block
should face upward and be nearest the top of the ramp. To test,
brush the 5 ml of lubricant as evenly as possible onto the metal
surface of the ramp. Ready the stopwatch and release the metal
block from the top edge on "3, 2, 1, GO!" (releasing on "GO!").
Stop the watch when the front edge of the block touches the end
of the ramp. Record the time on your data chart. Now use the
paper towels and white vinegar to remove the lubricant from the
ramp. Do not touch the surface again because of the oil from
your fingers. Repeat the experiment for each of the four
lubricants three times.
III. Analysis of Data:
When I finished the experiment I found my hypothesis to be
almost completely unsupported. Instead of vegetable oil having
the best (shortest) time, followed by baby oil, Softsoap, and
lastly Vaseline; Softsoap came in first followed by baby oil,
vegetable oil, and Vaseline. The only part that turned out as I
had predicted was that Vaseline would come in last. These are
the average times it took the block to read the end of the ramp
with each lubricant:
Softsoap = 0.63 sec.
baby oil = 0.88 sec.
vegetable oil = 1.01 sec.
Vaseline = 1.22 sec.
IV. Summary and Conclusion:
In my experiment, I found that, after three trials, Softsoap had
the best average, baby oil came in second, vegetable oil was
third, and Vaseline was last. Therefore, my hypothesis was
unsupported. My hypothesis stated that vegetable oil world work
the best and that it would be followed by baby oil, then
Softsoap, and finally Vaseline.
One thing I learned from this experiment was that just because a
substance is dense does not mean it cannot lubricate. This and
the data I collected caused me to reject my hypothesis. I ran
into only one problem while doing the experiment. That problem
was the cleaning of the ramp. I found using Dawn dish snap to
be unfair because one of the lubricants was soap, also. It also
left a very thin residue. In its place, I used plain distilled
white vinegar. This solved my problem.
V. Application:
To generalize my findings, I would say I have found that a
substance's ability to lubricate is not determined by its
density. There are not any uses for this knowledge now, but in
the future we may use these products in cars or moving
sidewalks. The possibilities are endless. Even after this
experiment, there are still questions unanswered. "Does the
angle of the ramp affect the ratio of the differences of the
lubricant's times?" is only one. "Would it make a difference if
the ramp was longer?" is another. Despite this research there
are many questions yet unanswered.
Title: Root Development
Student Researcher: Stephanie Frey
School Address: Hillside Middle School
1941 Alamo
Kalamazoo, Michigan 49007
Grade: 7
Teacher: Barbara A. Minar
I. Statement of Purpose and Hypothesis
I wanted to find out which type of water would help plants grow
roots the best, salt water, sugar water, distilled water, or
well water. I thought that well water would help plants grow
the longest roots and distilled water would grow the second
longest roots. I thought the plant given sugar water would have
the third longest roots and the plant given salt water would
grow the smallest roots.
II. Methodology:
I tested my hypothesis by purchasing a pothos at Wedel's
Greenhouse and asked the sales people which plant would make the
best clippings. I cut off four leaves and kept their stems. I
placed one plant clipping in each glass. I filled each glass
with 150.0 ml of one of the different types of water. I then
put plastic wrap over the mouth of the glass to cover the
opening to prevent evaporation. I cut a hole in the plastic
wrap and put the stem of the plant into the water. I put all
the glasses on the same window shelf in the southern part of our
dining room for 52 days and watched the root growth and changes
in the plant clippings. I did not take plants out of the water
until day 49 for actual measurements. If I had taken them out
of the water to measure them, the roots may have been damaged
and would affect the growth and the results would have been
inaccurate. My independent variable is the water type. The
dependent variable is the root development.
III. Analysis of Data:
My data showed sugar water grew roots 2.25 cm long. Distilled
water grew roots 0.50 cm long. Well water grew roots 0.50 cm
long. Salt water grew roots 0.0cm long.
IV. Summary and Conclusion:
When I experimented to see if plant clippings grew longer roots
with sugar water, salt water, distilled water, or well water I
found the best root growth in the sugar water. Salt water grew
the least roots. I had thought distilled water would have grown
the longest roots. This part of my hypothesis was not supported
by my data. I also thought that salt water would not grow long
roots. This part of my hypothesis was supported by my data.
V. Application:
From my research, I learned that distilled water can grow roots
even though the minerals have been removed, because of the
organic materials that are left behind. The amount of organic
materials depend upon the source of the water. City water can
have more chemicals in the water like fluoride for our teeth. I
found this out when I called the 800 number from Country Fresh,
the company that sold me the distilled water. Water out in the
country can have more organic materials in it because of the
crops and livestock. Farmers use more fertilizers and this can
get into the well water. Further research with salt water
plants world be helpful. Poorer nations could use this
information with crops when their rain fall is low and the
mineral content is high. This information would be helpful to
farmers trying to propagate plants.
Title: The Decomposition Of Different Foods In Different
Environments
Student Researcher: Michael DeSantis
School: Edgemont Jr./Sr. High School
200 White Oak Lane
Scarsdale, NY 10583
Grade: 7
Teacher: Mr. Rubenstein
I. Statement of Purpose and Hypothesis:
I wanted to find out which of the foods that I gathered would
decompose faster in two different environments. My first
hypothesis stated that soil will help the food matter decompose
faster rather than the twigs + grass mixture. My second
hypothesis stated that the food matter will decompose faster for
the room-temperature group rather than the cold-temperature
group. My third hypothesis stated that, of the three foods that
I selected (oranges, tomatoes, and potatoes), the tomatoes will
decompose the fastest.
II. Methodology:
For my experiment, I used plastic cups, soil, twigs, grass, a
shoe box, labels, a refrigerator, tape, a marker, a tomato, a
potato, and an orange.
After gathering the materials that I needed, I constructed the
base or containment for each of the two groups (cold/room
temperature). I then put the plastic cups into the bottom of
the shoe box (6 cups) and taped them down. I then filled them
with either the soil or the twigs + grass. I repeated this for
the top side of the shoe box. I placed the food into the
selected cups. Before I started to fill the cups, I made a data
chart. I placed one box into the refrigerator and one box in my
living room. I took a picture of each box every week and
recorded the percent of the food not decomposed of each cup
every day for 24 days.
The controlled variables were the size of the cups and the
amount of soil and the amount of twigs + grass mixture used.
The manipulated variable was the temperature in which each box
was kept. The responding variable was the rate of decomposition
of the foods being tested.
III. Analysis of Data:
As it turned out, my hypothesis was not entirely correct. The
food in the room-temperature box did in fact decompose faster.
The tomatoes also decomposed faster in both boxes. But the food
in the cups containing twigs + grass decomposed faster than the
food in the cups filled with soil.
Room Temperature
% Not Decomposed
Soil Twigs and Grass
Date Tomato% Orange% Potato% Tomato% Orange% Potato%
4/29/98 84 98 99 79 96 100
5/ 2/98 52 90 96 48 87 99
5/ 6/98 42 80 95 39 78 97
5/ 9/98 42 73 95 39 72 96
5/13/98 40 72 94 39 71 96
5/16/98 40 71 94 39 69 95
5/19/98 40 70 94 38 68 94
Cold Temperature
% Not Decomposed
Soil Twigs and Grass
Date Tomato% Orange% Potato% Tomato% Orange% Potato%
4/29/98 97 98 99 79 98 100
5/ 2/98 94 94 97 94 97 99
5/ 6/98 86 89 96 89 91 98
5/ 9/98 82 88 96 85 89 97
5/13/98 81 88 96 80 88 97
5/16/98 78 88 96 75 87 97
5/19/98 77 88 96 74 87 97
IV. Summary and Conclusion:
I found out that tomatoes are one of the fastest decomposing
foods, especially being compared with oranges and potatoes. But
to my surprise, I also found out that twigs + grass do
contribute by increasing the rate of decomposition compared to
soil. Room temperature is also better than cold temperature for
decomposing matters which is what I expected before conducting
this experiment.
V. Application:
The information I found out while conducting my experiment can
help the earth. For example, now that I know that twigs + grass
are better for decomposing foods than soil, people should use
twigs and grass for the ground (especially for a compost pile).
Also, land fills or places trying to minimize the amount of
garbage (including food scraps) should use twigs and grass for
the ground. Also, knowing that tomatoes are very fast at
decomposing, is useful information when planning a compost pile.
Title: The Effect Of pH On The Life Span Of A Tadpole
Student Researcher: Aaron Friedman
School: Edgemont Jr./Sr. High School
White oak Lane
Scarsdale, New York 10583
Grade: 7
Teacher: Ms. Maria Russo
I. Statement of Purpose and Hypothesis:
I wanted to know more about the effect of pH on a tadpole's life
span. pH is how acidic or basic a liquid is. Does the pH of
water in which a tadpole is placed affect its life span? Will
neutral water tadpoles live longer then acidic or basic ones?
My hypothesis stated that, if one tadpole lives in neutral water
and another lives in acidic water, the one in neutral will live
longer. I feel that a tadpole's water is naturally neutral and
if it is anything else it may be in danger of death or injury.
II. Methodology:
In order to test this hypothesis, I needed 6 bowls, 6 tadpoles,
tadpole food, acidic drops, basic drops, indicator strips,
water, and a net.
First, I filled 6 bowls with water. Two bowls then received 15
drops of acidic drops making their pH 9. Two other bowls were
left at pH 7. The last two bowls received 15 drops of basic
drops making their pH 5. I made sure each pH was correct by
testing the water with indicator strips everyday. I put one
tadpole in each bowl. Every other day, I changed the water and
reapplied the drops. Everyday, I feed them a pinch of food.
There are many other variables that I controlled. The tadpoles
were all placed on the same table and received the same amount
of oxygen. They also received the same amount of food and
water. Their water was changed at the same time and they were
fed at the same time.
The manipulated variable is the pH. The acidic tadpoles
received 15 drops of acidic drops. The basic tadpoles received
15 drops of basic drops. The responding variable is the number
of days the tadpoles stayed alive.
III. Analysis of Data:
My hypothesis was pretty correct. The acidic tadpoles did die
on the first day. As for the basic tadpoles, they did survive
the whole test (33 days). As the acidic tadpoles were dying,
their skin was shedding and they were trying to jump out of the
bowl. Many other odd occurrences happened during my testing.
For example, for about a week, one tadpole we lying upside down
and gasping for breath. Eventually, this ailment went away and
the tadpole was fine.
Tadpole # Days Alive
Acidic Tadpole #1 1
Acidic Tadpole #2 1
Neutral Tadpole #1 33
Neutral Tadpole #2 33
Basic Tadpole #1 33
Basic Tadpole #2 33
IV. Summary and Conclusion:
The acidic tadpoles did die before the neutral ones, but the
basic ones stayed alive as long as the neutral ones. Therefore,
tadpoles are able to survive if the pH is slightly basic. But
if the pH becomes slightly acidic, the results may be fatal.
V. Application:
In this fast changing world, many environments are being
destroyed and even ruined. If a tadpole needs to live in water
with a pH of 7, it is important to know that so we won't
accidentally change the pH. Also, things like acid rain could
definitely harm the water's pH. Not only is the pH of water a
problem for tadpoles, but all marine animals may be facing this
potential problem. I hope to continue my studies and may expand
it to include other animals.
Title: Mouthwash And Bacteria
Student Researcher: Chloe Asselin
School: Edgemont Junior/Senior High School
White Oak Lane
Scarsdale, New York 10583
Grade: 7
Teacher: Maria Russo
I. Statement of Purpose and Hypothesis:
I wanted to know more about how clean your teeth could be by
using mouthwash. To find how efficient the mouthwash was, I
found out how much bacteria was left after using two different
brands of mouthwash. I wanted to know if Fresh Burst Listerine
worked better than Tom's of Maine Natural Mouthwash. My
hypothesis stated that Fresh Burst Listerine worked better than
Tom's of Maine Natural Mouthwash.
II. Methodology:
First, I wrote my hypothesis thinking that Fresh Burst Listerine
was better than Tom's of Maine Natural Mouthwash because Tom's
of Maine did not say, on the bottle, that it destroyed bacteria.
I then got 23 grams of powdered agar, 1,000 ml of cold distilled
water, petri dishes, masking tape, and Q-tips. I already had
the bottle of Fresh Burst Listerine and the bottle of Tom's of
Maine Natural Mouthwash.
The manipulated variable was the kind of mouthwash. The
responding variable was how much bacteria grew. The variables
held constant were the size of the petri dishes, the amount of
medium in each petri dish, the amount of mouthwash used, and the
amount of bacteria spread in each petri dish.
For conducting the experiment, I first had to make the agar gel.
I suspended 23 grams of the medium into 1,000 ml. of cold
distilled water. I then heated the medium to boiling to
dissolve it completely. To sterilize the medium, I put it in
the microwave and heated it minute by minute. When the medium
began to bubble I turned off the microwave. I then poured the
medium into the deeper dish of the petri dish. Next, I taped
the petri dish and inverted it. The petri dishes were kept in a
warm place.
Then the real experiment was done. I took the tape off the
petri dish and took the top off. At 7:30 AM and 9:30 PM, my
brother and I used different mouthwash. We moved it back and
forth in our mouths 50 times. We then spit it out and wiped a
Q-tip along our bottom teeth. Next the Q-tip was smeared, in
three different places, on the agar gel in the petri dish. For
2 days, my brother and I did these tests at 7:30 AM and 9:30 PM.
I also did a control for each day, swabbing a Q-tip without a
rinse with mouthwash.
Next, I recorded my rating of the amount of bacteria grown on a
scale of 0-4. Finally, I accepted or rejected my hypothesis and
wrote a summary and conclusion. T he scale is from 0-4. O being
no bacteria, 1 being a little bacteria, 2 being some bacteria
and so on.
III. Analysis of data:
For 2 days, my brother and I did tests regarding bacteria. I
observed that Fresh Burst Listerine worked better than Tom's of
Maine Natural Mouthwash. The average number for Fresh Burst
Listerine was 3 (a lot of bacteria). The average number for
Tom's of Maine Natural Mouthwash was 4 (plate was overgrowing!!).
The control stayed the same both days with an average of 3 (a
lot of bacteria).
IV. Summary and Conclusion:
Fresh Burst Listerine worked better than Tom's of Maine Natural
Mouthwash. The control had a lot of bacteria, but not
overflowing in the petri dish. On the bottle of Fresh Burst
Listerine, it says the mouthwash will kill germs and keep your
breath fresh. On the Tom's of Maine bottle it just says the
mouthwash will keep your breath fresh. Therefore, I accepted
my hypothesis which stated Fresh Burst Listerine would work
better than Tom's of Maine Natural Mouthwash.
V. Application:
I can apply this information to my life because I now know to
use Fresh Burst Listerine if I want clean teeth and a fresh
breath, which indicates the removal of bacteria. The Consumer
Report Magazine should also conduct this experiment to show the
public the benefits of using Fresh Burst Listerine.
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