…..significant figures…..units…..show your work…..significant figures..…units…..show your work…..
Name_____________________________
8th Grade Science Mid-Year Exam / Cumulative Test / Pop-Quiz (if you forgot…)
On all problems, significant figures count. Show your work for potential partial credit.
1. I have a bag of marbles and want to know what portion of the contents is air and what portion is
solid glass marble. To do this, I measure the volume of marbles and air to be 60.0 ml. I then pour
85.0 ml of water into the graduated cylinder containing the marbles. The total volume of the water
and marbles reads 115.0 ml.
a. What is the volume of the solid glass marbles? (5 pts)
b. What is the percentage of the air in the marbles (before mixed with the water)? (3 pts)
Extra Credit: (1 point)
What mathematician is credited with first describing the principle of displacement to find volume?
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…..significant figures…..units…..show your work…..significant figures..…units…..show your work…..
2. Solve each of the following and circle your final answer (correct significant figures!!).
Carefully notice if each problem is addition, subtraction, division, or multiplication. (2 pts each)
a. 48.1 ÷ 6.00 =
b. 6 ÷ 14.2 =
c. 17.200 × 0.305 =
d. 28 × 14.7 =
e. 689.2 – 3.1 =
f. 1.344 – 0.03 =
g. 0.0034 + 0.006 =
h. 21.034 + 2.01 =
3. Use the table below to answer the questions about the mass of a stopper.
The table shows the results of 25 students massing a single rubber stopper.
All 25 students massed the same stopper. Results are recorded in grams.
Student
Group
Group A
Group B
Group C
Group D
Group E
Result 1
Result 2
Result 3
Result 4
Result 5
24.1
24.4
24.6
24.3
24.4
20
21
20
20
20
23.998
23.833
23.349
23.194
23.833
24.02
24.04
24.05
24.01
24.04
21.22
25.54
24.02
24.3
20.89
a. Which group is most accurate? WHY do you think this? (4 points)
b. Which group is most precise? WHY do you think this? (4 points)
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4. How are we limited in what we can explore and learn about using science? (3 pts)
5. What is the density of a cube measuring 12.5 cm on each side with a mass of 35.66 grams? (3 pts)
6. What is the difference between the property of a substance and the property of an item? (4 pts)
7. Name two properties of substances (characteristic properties) we have studied. (2 pts)
8. Name two properties of items we have studies. (2 pts)
9. What does the Law of Conservation of Mass state? (3 pts)
Extra Credit:
What Frenchman is credited with first describing the Law of Conservation of Mass? (1 pts)
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10. I pour 200.0 ml of flat soda into my mug and I measure and record the density as 0.90 g/ml. With
the same flat soda, I pour 50.0 ml more into the mug. What is the density of the 250.0 ml of liquid
in the mug? (3 pts)
11. On the attached graph are recorded temperatures of two different test tubes of goop.
The goops were put into a double-boiler and the water was heated with the test tubes.
I recorded the temperature of each test tube every 30 seconds.
Test tube A contains 50 ml of goop and test tube B contained 100 ml of goop.
The goops started as clear liquids and, at the end, were opaque white solids.
a.
What would you guess is the freezing point of goop A? (2 pts)
b.
What would you say is the freezing point of goop B? (2 pts)
c.
Do you think Goop A and Goop B are the same material? Why or Why not? (4 pts)
d.
Sra. Dolphin told me that the difference in the freezing points is due to the different
volumes of material in each test tube. What would your response be to her? (3 pts)
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