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SEQL Student Pre/Post-Test

6th Grade Science

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ANSWER KEY

Lawrence’s class has been learning about mass and volume. Lawrence observed that 50 ml of water has a mass of 50 grams. Lawrence wondered if the mass of the water would change if he would freeze or evaporate the water in a closed container. Lawrence did an experiment to see if the state of matter changed the mass of water. Below are his procedures.

(Science 1.1.I.a; Science 7.1.A.c)

1. Measure 50 ml of water and put it in a plastic freezer bag. Repeat this step two times for a total of three freezer bags each containing 50 ml of water. Do not open the bags during the experiment, so no water escapes.

2. Measure and record the masses of each of the freezer bags of 50 ml of water separately. (Subtract four grams from each bag of water for the mass of the plastic freezer bag)

3. Put the freezer bags of water in the freezer over night.

4. The next day take the bags out of the freezer and measure and record the masses of each of the frozen bags of water.

5. Let the ice in the bags melt. When the ice is completely melted, set the three bags in the sun until part of the water is evaporating and condensing on the sides of the bags.

6. Measure and record the mass of each bag of water, which now contains some water vapor.

Answer the following questions about the experiment:

1. Independent Variable? (Science 7.1.A.b) State of Matter (Solid, Liquid, Gas/liquid)

2. Dependent Variable? (Science 7.1.A.b) mass of water, grams of water

3. Write a testable question that could be the basis of Lawrences’s scientific investigation.

(Science 7.1.A.a)

Any question that shows the effect of the independent variable on the dependent variable

Examples

How does the state of matter effect the mass of water?

Will frozen (gas, solid) water have more (less) mass?

Does the mass of water change when you change the state of matter?

4. Write a hypothesis for the testable question you wrote above. (Science 7.1.A.a)

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Any hypothesis that shows the affect of the independent variable on the dependant variable. The hypothesis must answer the testable question. The hypothesis can be incorrect. The hypothesis should be written as an If/then statement

Examples

If we change the state of matter of water, then frozen (liquid, gas) water will have more (less) mass.

If we change the state of matter, then it will not affect the mass of water.

If we change the water from a liquid to solid, back to liquid, then to gas, then the mass of water will not change.

If we change the state of matter of the water, then the mass of the water will remain constant (the same).

5-6. To make a fair experiment, Lawrence kept several factors constant during the experiment. List two factors he should keep the same. (Science 7.1.A.b)

Any two variables that are kept constant for each test.

Examples

Type of plastic freezer bag, size of plastic freezer bag, freezer, position of bags in the sun, graduated cylinder, origin of water, original volume of water placed in the bag, scale or balance

7. Choose the statement about independent and dependent variables that is correct.

(Science 7.1.A.b)

a. The dependent variable is the one variable that is changed in an experiment and the

independent variable is the responder variable.

b. A conclusion cannot be made about what changed the dependent variable unless you only change one independent variable.

c. The independent and dependent variable need to be the same.

d. Many variables can be tested at once so more data can be collected and more

conclusions can be made in less time.

The data Lawrence obtained during his experiment is given in the table below.

Mass (g) of Various States of Matter of Water
Mass (g)
State of Matter / Bag 1 / Bag 2 / Bag 3 / Mean
Liquid / 50 / 50 / 50 / 50
Solid / 50 / 50 / 50 / 50
Gas/Liquid / 50 / 50 / 50 / 50
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8-11. Use the data from the table to construct an appropriate graph on the grid below.

Graph only the mean of the masses of water. (Science 7.1.B.e; 7.1.C.a; 7.1.D.a)

Each of the four items on the graph listed below is worth one point each.

Be sure to provide:

-  an appropriate title

-  a label for each axis with appropriate units

-  an appropriate number scale and category labels

-  correctly plotted data

State of Matter vs. Mass of Water

Liquid Solid Gas/Liquid

State of Matter

12. Use the data table and graph to write a conclusion for the experiment.

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(Science 1.1.I.a; Science 7.1.C.a; Science 7.1.D.a)

Any conclusion that shows how the independent variable affects or

does not affect the dependant variable.

Examples

The state of matter did not affect the mass of water.

The mass of water stayed the same.

Frozen water has the same mass as liquid water and water vapor.

13. Analyze whether the data Lawrence collected supports your proposed hypothesis.

(Science 7.1.C.e)

The data Lawrence collected supports (does not support) the hypothesis because.....

Examples

I predicted that the state of matter of water would not affect the mass of water.

I predicted that the mass of water would be more in the solid state.

I predicted the mass of water would change with the state of matter.

14. Why did Lawrence conduct multiple trials to test the design of his valid experiment?

(Science 7.1.A.b)

a. It is more fun if you test something many times.

b. You need to find the total of all of the trials to make a larger number.

c. Your results are more reliable if you test your hypothesis several times and calculate the mean.

15. How would you classify this type of investigation? (Science 7.1.A.e)

a. observing and describing objects, organisms, or events

b. collecting specimens

c. experimenting

d. making observations in nature

e. discovery of new objects and phenomena

f. making models

16. What scientific tool could Lawrence use to measure 50 ml of water?

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(Science 1.1.A.b; Science 7.1.B.b,c,d,e)

graduated cylinder, 50 ml beaker, measuring cup

17. What scientific tool could Lawrence use to measure the mass of the water?

(Science 1.1.A.c; 7.1.B.b,c,d,e)

Balance, scale

18. Is the change of state of water a chemical or physical change? _____physical_____

(Science 1.1.G.a,c)

19. Water has mass and volume, therefore it is ______. (Science 1.1.A.a)

a. an element

b. matter

c. a mixture

d. a mineral

20. Which statement is true about volume and mass? (Sci 1.1.A.b,c)

a. Volume is the amount of matter in an object and mass is the amount of space an object

occupies.

b. Volume is the weight of an object, and mass is the shape and size of an object.

c. Volume is the amount of matter in an object and mass is a measure of an objects density.

d. Volume is the amount of space an object occupies and mass is the

amount of matter in an object.

SEQL Student Pre/Post-Test

6th Grade Science

Scoring Rubric

Points Points

Question # Possible Earned Criteria

1) 1 point _____/(1) Correct answer written

2) 1 point _____/(1) Correct answer written

3) 1 point _____/(1) Question is testable and is about the effect of

State of matter on mass of water.

4) 1 point _____/(1) Hypothesis answers the question and guesses the

affect of State of matter on mass of water.

5) 1 point _____/(1) At least 1 controlled variable is listed

6) 1 point _____/(1) At least 1 controlled variable is listed

7) 1 point _____/(1) Correct answer selected

8) 1 point _____/(1) Appropriate title is labeled

9) 1 point _____/(1) Label for each axis with appropriate units

10) 1 point _____/(1) Appropriate number scale and category labels

11) 1 point _____/(1) Correctly Plotted Data

12) 1 point _____/(1) Conclusion is about the affect of State of matter

on mass of water.

13) 1 point _____/(1) Correct analyzing of student hypothesis in

relation to the data

14) 1 point _____/(1) Correct answer selected

15) 1 point _____/(1) Correct answer selected

16) 1 point _____/(1) Correct answer written

17) 1 point _____/(1) Correct answer written

18) 1 point _____/(1) Correct answer written

19) 1 point _____/(1) Correct answer selected

20) 1 point _____/(1) Correct answer selected

Total Points _____/20