WMS—Science 8—ASSESSMENTS
Learning Target: MS5—I can describe and perform a separation of a given mixture.
Name: ______________________________ Group #_____ Period:____
Expectations: You will work in your assigned lab group throughout the period on the practical
exam. You may not communicate with any other students outside of your lab group for any
reason; this will be considered cheating and will result in you having to take your performance
assessment again, individually, to receive a score.
You will be required to wear goggles throughout the class period since the chemicals we are
working with may harm your eyes in the event of a spill.
You will have only this period to work on the exam; extra time cannot be given and you will be
scored on how much you have finished at the end of the period. Do your best and ask your teacher
if you have any questions. Make sure you do not communicate with anyone besides Ms. Bryn!
Be sure to write neatly in complete sentences and read all directions very carefully.
Do not turn the page until instructed to do so by your
teacher.
Train Wreck Mystery
WMS—Science 8—ASSESSMENTS
A train on its way through Tacoma has derailed and crashed due to the weather. During the train
crash, several cars full of chemicals spilled onto the roadway and into a nearby river. The police
and fire crews are so busy cleaning up the train wreck that nobody has had a chance yet to
determine whether or not the chemical spill could be a danger to human health and the water
supply. The men operating the train are able to tell you that the substance in the box cars was a
mixture of three different substances.
Your task:
1) Do your best to identify the substances in the chemical mixture based on their properties
2) Separate the mixture into its parts so they can be taken back to the lab for further testing
The train operators were pretty shaken up and could not remember what substances were on the
train; however, their travel log shows that they sometimes transport the substances in the table
below through Tacoma. The train operators DO know that what was in the box car was a mixture
of three substances.
The three substances in the mystery mixture could be any of the substances listed in the table
below.
Table 1. Possible Substances in Mystery Train Mixture
Substance
Identifying Properties
Sulfur
Solid at room temperature. Pale yellow; typically possesses
a rotten egg smell. Insoluble.
Hydrogen Gas at room temperature. Flammable. Colorless, odorless.
Iron filings Solid at room temperature. Typically dark in color. Metal.
Magnetic (will move when exposed to a magnet). Insoluble.
Copper
Solid at room temperature. Small, blue crystals. Soluble.
sulfate
Sand
Solid at room temperature. Small, variable crystals.
Insoluble.
RIT dye
Solid at room temperature. Tiny, purple crystals. Soluble.
Sodium Solid at room temperature. White, round crystals. Soluble in
Nitrate
water.
Sodium Solid at room temperature. Soluble in water (dissolves in
chloride water). Tiny, white crystals.
Zinc oxide Solid at room temperature. Fine, white powder. Insolube.
Name:_________________________Date:____________Per:_______Pod:______
WMS—Science 8—ASSESSMENTS
1. Use the information from Table 1 and the tools in your bin to identify the three
substances in your mixture, and provide evidence that supports your claim. You may or
may not need to use all of the tools in your bin to identify the three substances in your
mixture.
Claim: My mixture contains ______________________________________________________.
Evidence: Provide at least two pieces of evidence to support your claim.
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2.
Now it’s time to try to separate the mixture so you can bring it back to the lab. Write down
a procedure for how you plan to separate the three substances in the space below
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3. Once you have it written down, raise your hand for teacher approval before you
attempt to separate the substances in the mixture. Your teacher will give you any
additional equipment you need to perform the separation.
WMS—Science 8—ASSESSMENTS
4. After you finish the separation, raise your hand and wait for your teacher to check your
separation results.
5. After the teacher gives you clean up approval, you must complete the following:
A. Clean up all of the equipment you used and put it back in the bin. Carefully use soap,
test tube brushes, and water to clean your equipment. If you do not to clean up or
follow safe lab procedures, you will be delayed from leaving the classroom on
time.
B. Once all of your equipment is clean and in its bin, raise your hand and the teacher
will come and remove the bin.
C. The teacher will then collect your exams.
6.
After you have turned in your exams, select something to work on by yourself.
Grading Rubric for Performance Assessment (Your Teacher will Mark your Score here)
Learning Target: MS5—I can describe and perform a separation of a given mixture.
Level Achieved
Teaching Others
Working Independently
Working With Support
Just Starting
Summative
Missing/Incomplete
Description
 Student clearly identifies each substance in the mixture and provides clear, accurate
evidence for how it was identified.
 Student writes clear, logical procedure in numbered steps that correctly explains how
to separate all three substances in the mixture.
 Student performs procedure and successfully separates each of the three substances.
 Student clearly identifies each substance in the mixture, but some evidence may be
unclear.
 Student writes procedure in numbered steps that explains how to isolate all three
substances in the mixture, but it may not be clear, logical, or complete.
 Student performs procedure and successfully separates each of the three substances.
 Student clearly identifies each substance in the mixture, but is greatly lacking
evidence OR student misidentifies one substance in the mixture.
 Student writes procedure in numbered steps that explains how to separate all three
substances in the mixture, but it is missing steps, vague, or otherwise incomplete.
 Student attempts to perform procedure but has difficulty separating substances.
 Student incorrectly identifies more than one substance.
 Procedure is incomplete or unclear.
 Student is not able to finish performing the procedure in the time allotted.
Student has completed less than half of the written performance assessment, had to be
removed from lab, or was absent the day of the performance assessment.