Directions - Norwalk PS

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Directions: Challenge yourself! Print out the “quiz” or get a pen/pencil and paper and record

your answers to the questions below. Check your answers with the key to see how well you did

and then go back using the explanations to see why you were correct or incorrect.

Good luck!

Scientific Investigations

1. Katy has to do a science project that involves making a model. Which of the following questions
would she answer with a model?

A. How does a volcano's lava flow affect the plants and objects in its path?
B. What type of tree is the prettiest?
C. How fast can different plant species grow?
D. Which type of bug can move the fastest?

2. Annabelle loves to learn about plants. For a class project, she thought of the following question:
Do plants enjoy when people sing to them?

This question is

A. not a valid scientific question because it is not testable.
B. not a valid scientific question because it is about plants.
C. a valid scientific question because it is testable.
D. a valid scientific question because it is about plants.

3. During an experiment, Sandy recorded incorrect observations and measurements. What would be
the most serious outcome of the mistakes?

A. Sandy would reach an incorrect conclusion.
B. Sandy would change the method.
C. Sandy would write a poor report.
D. Sandy would have to repeat the experiment.

4. Which of the following is the strongest claim?

A. a claim that is supported by multiple sources of scientific evidence
B. a claim that is presented face-to-face
C. a claim that is supported by a complex experiment that lasted 6 months
D. a claim that has been made multiple times by the smartest scientist

5. Dr. Burke performs an experiment to determine how plants grow in a variety of temperature and
moisture conditions. He runs five trials with five different groups of the same species of plant. The
table below shows the results from his experiment.

Plant Group Temperature Moisture Average Plant Growth

Group 1 high high 2 in

Group 2 moderate moderate 6 in

Group 3 low low 0 in

Group 4 high moderate 3 in

Group 5 moderate high 4 in

After finishing the experiment, Dr. Burke explains that heat and moisture have no effect on plant
growth. Based on the evidence shown in the table, is his explanation valid?

A. No, the evidence shown in the table does not support his explanation.
B. Yes, the evidence shown in the table supports his explanation.
C. No, he did not test plants in moderate moisture and moderate temperature conditions.
D. Yes, his experiment is well designed so his results do not need to support his explanation.

6. Omar wants to determine if the mass of a model rocket affects how long the rocket is able to stay up
in the air. To do this, he constructs three identical rockets and then fills two of the rockets with
varying amounts of sand to add mass. He then launches the rockets one at a time and times how
long they are able to stay airborne.

What is the independent variable in Omar's experiment?

A. the materials out of which the rockets were made
B. the force with which each rocket is launched
C. the masses of the model rockets
D. the time the rockets remain airborne

7. In school, Jarrett learned that salt lowers the freezing point of water. He wants to test this in a home
experiment. He adds an equal amount of salt and room-temperature water into three identical
containers. Which of the following is a control of his experiment?

A. the amount of water in each container
B. the type of container used
C. the amount of salt in each container
D. all of these

8. Silkworms are raised commercially for the silk cocoons that they produce. In ten different trials,
Jami's class raised silkworms under different temperatures to see what conditions are best for
silkworm caterpillars in their first three instars or stages. In each trial, they began with 30 silkworm
eggs.

The table below shows the data Jami recorded.

Trial Number Temperature Number Surviving
(°F) to Adulthood

1 55 0

2 60 1

3 65 1

4 70 3

5 75 6

6 80 12

7 85 26

8 90 19

9 95 7

10 100 0
Which statement below does the data support?

A. Silkworms can grow successfully at any temperature.

B. Too much heat or too little heat is bad for the growth of silkworms.
C. Temperature is not a condition that affects the survival of silkworms.
D. Ninety degrees is the perfect temperature for growing silkworms.

9. Dr. Jalli wonders what antibacterial, or cleaning substance, kills the most bacteria. He designs an
experiment to test four antibacterials by putting them onto colonies of bacteria and measuring how
much of the bacteria is killed. His results from each of three trials are listed below:

Antibacterial % Bacteria Killed Antibacterial % Bacteria Killed

1 65% 1 72%

2 23% 2 17%

3 18% 3 21%

4 31% 4 39%

Antibacterial % Bacteria Killed
1 75%
2 12%
3 18%
4 29%

From the information in the tables, which of the following is an appropriate conclusion?

A. None of the antibacterials killed any bacteria.
B. All of the antibacterials had the same effectiveness at killing the bacteria.
C. Antibacterials 2 and 3 were the most effective at killing the bacteria.
D. Antibacterial 1 was the most effective at killing bacteria.

10. Two teams of scientists studying lung disease have each developed a new drug. Each team claims
that its drug will greatly fight lung disease.

The two teams have agreed to join together to fight lung disease, but they only have enough money
to continue developing one of the drugs. How do they decide which drug to continue developing?

A. The drug that took longer to develop is better because the scientists worked harder to develop it.

B. They should choose the drug that cost the most to develop—it will be more effective than the cheaper

drug.

C. They should evaluate all the current scientific evidence and develop the drug that is better at fighting lung
disease.

D. It doesn't matter which drug they choose because they were both developed by scientists.

11. Jordan wants to conduct an experiment to see if plant food makes a difference in how well plants
grow. He gets 10 pots and plants a different type of seed in each. He gives plant food to half of the
plants and does not give plant food to the rest. He records the amount of plant food given to the
plants. But, he decides not to write down the types of seeds he planted. Will someone else be able to
repeat the experiment and find reliable results?

A. No, the results would not be reliable since not all of the plants were given plant food.
B. No, because Jordan should have used the same type of seeds in each pot, and should have recorded the

type of seeds.
C. Yes, because the type of seed is not important. As long as some of the plants are receiving plant food and

some are not, the experiment will give the same results.
D. No, because Jordan would need to use all vegetable seeds for the experiment to be reliable.

12. Min did an experiment to test the following hypothesis:

"If you increase the length of a lever, then you will increase the amount of work it can do without
having to increase the amount of force applied to the lever."

The summary of Min's results are in the table below:

Lever Length Amt of Force Applied Amt of Work Done

(in meters) (in Newtons) (in Joules)

1 m 100 N 100 J

2 m 100 N 200 J

3 m 100 N 200 J

While analyzing his experiment, however, Min made a mistake calculating the amount of work done
with the 3 m lever. How will this mistake most likely affect Min's conclusions?

A. Min may incorrectly conclude that the lever length does not necessarily affect the amount of work done.
B. Min will correctly conclude that the lever length always affects the amount of work done.
C. Min will not be able to draw any conclusions from the data he collected.
D. The mistake will not affect Min's conclusions.

13. Derek lives in a hot, humid climate. He has two rose bushes in pots in his yard. The rose bushes grow
quickly and bloom with large, red roses. Derek moves to a cold, dry climate at the same altitude and
notices that his rose bushes stop growing and do not have large blooms. He hypothesizes that the
rose bushes are not receiving enough water because he is now in a dry climate. He waters them
more often, but they do not improve.

Which of the following scientific questions should he ask next to find out what is wrong with his
roses?

A. Do rose bushes grow better in high or low altitudes?
B. Which rose bush has larger, more colorful blooms?
C. Does temperature affect the growth of the rose bushes?
D. How much do rose bushes cost in his new area?

14. Jennifer was doing an experiment to find out which type of plant would grow the tallest in one
month. For her experiment, Jennifer chose four types of plants. She then put each plant in soil,
placed the plants on the window, and watered the plants daily. She repeated the trial three times
and recorded her results in the tables below.

Plant type Growth (in inches) Plant type Growth (in inches)

1 5 in. 1 15 in.

2 17 in. 2 8 in.

3 8 in. 3 24 in.

4 2 in. 4 17 in.

Plant type Growth (in inches)
1 21 in.
2 6 in.
3 14 in.
4 9 in.

From the results above, Jennifer concluded that Plant 1 grew the tallest in one month's time. Is this a
valid conclusion?

A. Yes. Plant 1 was tallest in one of the trials, so the conclusion is valid.
B. Yes. The data from the first two trials are wrong, and plant 1 is really the tallest.
C. No. Plant 2 grew the tallest of all the types of plants that she studied.
D. No. The data were different in each trial, so one valid conclusion could not be made.

15. Nick wants to find out what the melting point of wax is. He has a block of wax, a graduated cylinder,
a pan, a thermometer, and scales. Which is the best procedure to follow for the experiment?

A. Place the wax in the pan and heat it until it melts. Then pour the wax into the graduated cylinder and
measure its volume.

B. Weigh the wax with the scales. Then heat it until it melts and weigh the wax a second time.
C. Place the wax in the pan and heat it until it starts to melt. Then measure its temperature.
D. Measure the wax’s temperature. Then heat it until it melts and weigh it on the scales.

16. Arthur is testing how well various types of disinfectants can kill E. coli bacteria. He starts with a Petri
dish that is covered with a colony of E. coli. He puts exactly one milliliter of each different
disinfectant at a different location on the Petri dish.
If a disinfectant works, it will eliminate the bacteria in the area in which it was placed. Two days
later, Arthur will measure the amount of bacteria that has been cleared out by each disinfectant.
Which of the following is the changed variable in this experiment?

A. The type of bacteria used
B. The Petri dish used
C. The length of time that the disinfectant is used
D. The type of disinfectant used

17. Glenn formulated the following question that he wanted to use for a scientific investigation:

How many planets are in the nearest galaxy?

Is this a valid question for use in Glenn's scientific investigation?

A. No; it is not testable.
B. No; it is not connected to science.
C. Yes; it is connected to science.
D. Yes; it is testable.

18. Olivia researched insects that destroy farmers’ crops. Based on this information, she discovered a
way to keep the insects away from the plants, without adding any harmful chemicals to the crops.
She recorded her conclusion, but did not write down any of the resources she used to learn about
the insects. She also did not record information about any of the trials that did not work. Does she
need to include this information?

A. Yes, because the information could be helpful to other scientists conducting similar research.
B. She should include the sources of the articles she read, but the trials that did not work are not important.
C. No, because Olivia put a lot of time and effort into finding this information. Other people should have to

do the same.
D. No, because she is the one who made the discovery. Listing the resources she used would give credit to

other people.

19. Beth wanted to find out whether or not salt affects how quickly ice melts. She used an ice cube tray
to make 10 ice cubes of the same shape and size. Then, she placed the ice cubes on the same
windowsill. She sprinkled each ice cube with one teaspoon of salt, and timed how long it took for the
cubes to melt. She recorded all of the data.

If someone else read the data, would he or she be able to make an accurate conclusion about the
effect of salt on ice?

A. No, because the data does not show how quickly the ice would have melted without the salt.
B. Yes, because Beth used only one independent variable and everything else was the same.
C. Yes, because using 10 ice cubes gives enough trials for the results to be accurate.
D. No, because Beth should have used a different amount of salt on each of the ice cubes.

20. Jami is doing an experiment to find out how temperature slows down or speeds up the sprouting of
bean seeds. To prepare for the experiment, she plans to put soil into three styrofoam cups and place
six seeds in each cup.

When Jami performs the experiment, which of the following should she keep the same for all of the
cups of beans?

I. the amount of sunlight
II. the amount of water
III. the temperature
IV. the amount of fertilizer

A. II and III only
B. I and II only
C. I, II, and IV only
D. I and III only

Answers

1. A
2. A

3. A
4. A
5. A

6. C
7. D
8. B
9. D
10. C

11. B
12. A
13. C
14. D
15. C
16. D
17. A
18. A
19. A
20. C

Explanations

1. Models are used in science experiments, where the actual problem is not easily found or created. Thus, a small
model of the event or object to study is made and the experiment is performed on the model.

A good example of an experiment that would need a model is to answer how a volcano's lava flow affects
the plants and objects in its path.

2. Good scientific questions must be testable, and they can be answered using data and facts obtained from
research, observations, or experiments. Good scientific questions do not ask about opinions or emotions.

"Do plants enjoy when people sing to them?" is not testable because it is not possible to ask a plant whether it
enjoys something or not. Therefore, Annabelle's question is not a valid scientific question.

A possible, valid scientific question on this topic is "Do plants grow faster when people sing to them?" This
question is valid because it is testable, and it does not ask about emotions.

3. When experiments are completed, the observations and measurements made are used to reach conclusions.
If the observations and measurements are incorrect, then a wrong conclusion would be reached. Since
experiments are meant to reveal truths, this is the most serious effect of errors.

4. Regardless of how it is presented, a claim that is supported by multiple sources of scientific evidence is
stronger than claims made by a single person or claims supported by only one experiment.

5. Dr. Burke's explanation is not valid because the evidence shown in the table does not support the
explanation.

According to the table, plants that receive low heat and moisture do not grow at all. Plants that are grown in
moderate temperature and moisture conditions grow the most.

6. Variables are the parts in an experiment which change. Independent variables determine the values of the
dependent variables.

In Omar's experiment, the independent variable is the mass of the model rocket. This variable is controlled
by Omar and ultimately determines the values of the dependent variable (the amount of time that the rockets
remain airborne).

7. A controlled variable is a part of an experiment that is held constant throughout the experiment. A changed
variable is the factor that is being purposely changed throughout the experiment.

In this case, the type of container used, the amount of water in each container, and the amount of salt in each
container are identical for each sample. Since these factors are being held constant, they are controlled
variables in the experiment.

8. Though none of the trials showed 100% survival for all 30 silkworms, 85 °F looks to be the best temperature of
the ones that the class tried. That does not make it ideal, however; more trials would have to be run before
that significant of a conclusion could be drawn.

The data easily shows that too much heat or too little is bad for the growth of silkworms.

9. From looking at the tables, the percentage of bacteria killed is highest for antibacterial 1. Thus, antibacterial 1
was the most effective at killing bacteria.

10. Evidence is needed when making scientific decisions. The scientists should evaluate all the current evidence
from both teams as well as other sources. Since the scientists are all working against lung disease, they need
to develop the drug that is better at fighting the disease.

11. For an experiment to be reliable, there can be only one independent variable. In this scenario, there were two.
The first was whether or not the plants were given plant food. The second was the type of seed. For the test to
be reliable, he should have used the same kind of seed for each plant. Then, some should have been given

plant food while the rest were not. If someone else were to repeat the experiment, they would need to know
what types of seeds were used. And, they would need to have only one independent variable in order to get
reliable results.

12. Mistakes in making and recording measurements or performing calculations can lead scientists to draw
incorrect conclusions.

If Min had not made a mistake with the work calculation, Min would have been able to see a clear and
consistent pattern of the lever length increasing the amount of work done by the lever.

13. The first climate that Derek lived in was hot and humid. He moved to an area that was cold and dry. The rose
bushes grew well in the hot, humid climate but started to die in the cold, dry climate. Derek first asked if the
difference in moisture was causing the rose bushes to die. He watered them more, but there was no change.

Since his new climate is cold instead of hot, the next question Derek should ask is: "Does temperature affect
the growth of the rose bushes?"

14. No. The data were different in each trial, so one valid conclusion could not be made.

The data in each table lead to a different conclusion, which means that there is not one correct answer for the
experiment as a whole. In order to draw a conclusion, data from multiple trials of an experiment need to lead
to the same conclusion.

15. When you are planning an experiment write down what types of data you need in order to answer your
question. In this case, Nick needs to know the temperature of the wax when it starts to melt. To determine
this, he should measure the temperature of melting wax.

16. A controlled variable is a part of an experiment that is held constant throughout the experiment. The changed
variable is purposely changed throughout the experiment.

In this case, different types of disinfectants are being tested. Therefore, the type of disinfectant used is the
changed variable of the experiment.

17. A question for a scientific investigation needs to be testable; it also needs to be connected to science
concepts.

The question about the number of planets in a galaxy is connected to science, but it is not testable because he
is unable to travel to the nearest galaxy, nor can he detect the planets from Earth.

18. It is important to include all information, including resources and unsuccessful trials. This information could be
beneficial to other scientists. They could use this information to further benefit the farmers and the
consumers who buy the food from the crops.

19. Scientific experiments must have a control group to be used for comparison. The control group is exposed to
the same conditions, without being exposed to the independent variable. In this case, Beth should have
placed several identical ice cubes in the windowsill without any salt. This would show how quickly the ice
would melt without salt. Someone reading the data could then make a conclusion based on the results. The
melting times of the two groups of ice cubes could be compared to determine whether or not salt affected
how fast ice melts.

20. When performing an experiment, it is important to change only one independent variable at a time.

In this experiment, since Jami wants to see how different temperatures affect sprouting, she must change the
temperature, but she should leave the amount of sunlight, water, and fertilizer the same for all of the cups
of beans.

If Jami changes two variables—such as temperature and water—at the same time and then finds that some of
the beans sprouted faster than others, she will not know which change caused the sprouting to speed up.

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