1. Tommy performed an experiment to test the solubility of sodium chloride in water. After he completed his experiment, he discovered that he had a few unused grams of NaCl leftover in a beaker. What should he do with the excess NaCl?

A. Pour the excess back into the original reagent container.
B. Pour the excess into the trash.
C. Ask the teacher about the proper place to dispose of the waste.
D. Pour the excess down the sink.

2. Arthur is studying plants, and he wants to learn more about why tree leaves change colors in the fall. His teacher suggested that he do a scientific experiment, starting with making a testable hypothesis. Which of the choices below is a possible hypothesis for Arthur to investigate?
A. My house has more trees around it than any other house on our street.
B. Why do some leaves change colors, and others don't?
C. If I water the trees in my yard all winter, will they stay green until spring?
D. If I stop watering the trees in my yard early in the summertime, their leaves will change color before the neighbors' trees change.

3. Shakita wants to know if the pH of an open can of soda changes over time. To test this, she designs an experiment that will involve the following steps.
Open a can of soda and measure the pH.

Allow the open soda can to rest undisturbed on a level countertop at room temperature.

Measure the pH of the open soda can every day at the same time for ten consecutive days.
What is the dependent variable in Shakita's experiment?
A. the type of soda
B. the number of days
C. the pH of the soda
D. the temperature of the room

4. Convert to centimeters: 6.8 meters
A. 6,800 centimeters
B. 68 centimeters
C. 68,000 centimeters
D. 680 centimeters

5. What is the difference between a theory and an opinion?
A. A theory is supported by scientific evidence, while an opinion is not.
B. An opinion is supported by scientific evidence, while a theory is not.
C. A theory is a scientific fact, while an opinion is not.
D. An opinion is a scientific fact, while a theory is not.

6. A politician running for office tells a crowd at a rally that the only way to keep the food chain safe is to stop allowing the growth of genetically-modified crops, or GMOs. Should the politician's statement be considered a scientific fact?
A. No. He presented no scientific data to support his claim.
B. Yes. Public speakers are known to be experts in every subject.
C. Yes. He is probably friends with scientists who work with GMOs.
D. No. Only scientists can talk about scientific facts.

7. Of the choices below, which unit of measurement would be most appropriate for measuring the volume of a barrel?
A. milliliters
B. grams
C. millimeters
D. liters

8. Anna is conducting an experiment to determine how weather affects cell phone reception. She is trying to decide the best way to conduct her experiment in order to collect meaningful data.

Which of the following experiments would help Anna collect the best data?
A. Test a cell phone's reception in the exact same location under various atmospheric conditions.

B. Test different cell phones in different locations on days with clear weather.

C. Test different cell phones in different locations on days with rainy weather.

D. Test a cell phone's reception in one location with clear weather and in another location with rainy weather.

9. Sara wanted to do a scientific investigation that involved people and their sleep. She hypothesized that all people feel happier if they take a one-hour afternoon nap each day. Is her hypothesis valuable?
A. No; feelings are not testable.
B. Yes; it will finally prove that everyone should have an afternoon nap time.
C. No; hypotheses must not involve humans.
D. Yes; it will lead to new information on the results of napping.

10. A boy complains of stomach pain to his mother. Unable to resolve the issue herself, she takes the boy to the doctor. Which of the following might be a good hypothesis for the stomach pain?
A. The boy fell and hurt his stomach.
B. The boy ate something that upset his stomach.
C. The boy has an infection and needs antibiotics.
D. Any of these answer choices could be correct.

11. Susie is conducting an investigation to find out what type of fish are in two ponds near her house. The results are shown in the bar graph below.

How many more perch are in Pond 2 than Pond 1?
A. 5
B. 8
C. 1
D. 30

12. Convert 11.1 liters to centiliters.
A. 1,110 centiliters
B. 11,100 centiliters
C. 111 centiliters
D. 111,000 centiliters

13. Which of the following tasks should be performed before measuring the mass of any object on a triple-beam balance?
A. Make sure that the balance pan is clean and free of debris.
B. Make sure that the balance is on a level surface.
C. Make sure that all the counterweights are set to zero.
D. all of these

14. Convert 49.6 hectograms to grams.
A. 496 grams
B. 496,000 grams
C. 4,960 grams
D. 49,600 grams

15. Which of the following measures the amount of matter in a given object?
A. weight
B. density
C. mass
D. volume

16. Before using glassware in the lab, it is important to _______.
A. carefully inspect the glassware for cracks and chips

B. know the location of the classroom broom, dustpan, and broken glassware container

C. make sure that the glassware is clean and dry

D. all of these

17. Genevieve was working on a science lab. In her lab, she was combining two chemicals and timing how long the reaction took to form a precipitate. She repeated the investigation a total of five times. Her times are shown below.
trial time (min:sec)
1 08:37
2 07:59
3 08:16
4 08:21
5 08:03
The next day, the instructor told Genevieve that the standard time for her investigation should have been 8 minutes 7 seconds. Which of the following choices describes Genevieve's work in the lab?
A. Her test trials had a high level of accuracy but a low level of precision.

B. Her test trials had a high level of accuracy and a high level of precision.

C. Her test trials had a low level of accuracy but a high level of precision.

D. Her test trials had a low level of accuracy and a low level of precision.

18. As part of an experimental procedure, Tom must measure exactly 15 milliliters of distilled water. Which of the following tools should Tom use for this task?
A. a 250-mL graduated cylinder
B. a teaspoon
C. a small paper cup
D. a 20-mL graduated cylinder

19. Alexis was interested in the way mirrors reflect. The living room of Alexis' house had one big window in the front, and a very large mirror on the back wall. Alexis hypothesized that the room would heat up faster in the morning with the mirror on the wall than it would if the mirror were covered with a sheet that was the same color as the walls.

What will make Alexis' hypothesis valuable?
A. Any testable hypothesis is valuable.
B. It will be valuable only if it is proved incorrect.
C. It will be valuable only if it is proved correct.
D. It cannot be valuable because the investigation is in her house and not in the science lab.

4, 5, 6, 7, 8, 9, 12, 17 are wrong

can you please tell me the answers to those i don't get those

Anonymous -- you were banned for several days for repeatedly trying to get others to do your work for you. Please keep the same name for your posts and put some effort into your work.

k can you give me hints at least for thsoe>?

check these answers

4.d
5.a
6.a
7.c
8.a
9.a
12.c
17.b

check these answers

4.d - yes
5.a - yes
6.a - yes
7.c - no
8.a - yes
9.a - no
12.c - no
17.b - I don't know

check my answers :

1.c
2.d
3.c
4.c
5.c
6.c
7.a
8.d
9.b
10.d
12.a
13.d
14.c
15.c
16.d
17.d
18.d
19.a