Ellice M. Norman Teachers Academy for Math and Science
10 West 35th Street
Chicago IL 60616


This activity will help the middle school student understand the concept of
density. Students will develop and utilize skills in observing, predicting and
testing. Students will understand the concept of density as it relates to
liquids, solids and gases.

Materials Needed:

Grapes Paperclips
Molasses Corks
Oil Pieces of a candle
Water Woodchips
Red and blue food colorings Yellow clay
Pickling salt Density Results Sheets
Plastic cups (6oz.) Medicine droppers


1. Advance preparation: Make two salt water solutions. The first consisting
of 2000ml water, 600ml pickling salt and 20-30 drops red food coloring. The
second solution will contain 2000ml water, 300ml pickling salt and 20-30
drops blue food coloring.
2. Make "impure" clay by mixing woodchips with clay, forming this into the
shape of a crown.
3. Read the story of the king and Archimedes and tell the students that we will
experiment with our crown to determine if it is pure or impure.
4. Weigh pure clay of equal mass as that of the crown.
5. Determine the volume of the crown and the pure clay by immersing them
one at a time into a full container of water. Measure and record the amount
of displaced water for each object.
6. Distribute to each of four groups: Molasses, cooking oil, red solution,
and blue solution (4oz. of each in plastic cups)
4 medicine droppers
10 plastic cups
1 paperclip
1 cork
1 candle piece
1 grape
Hypothesis/Results sheets
7. Explain to the students that they are now going to hypothesize and
experiment with the densities of the liquids before them. The students will
weigh each of the four liquids and make hypotheses on the ranking of the
liquids from least dense to most dense. Their hypothetical ranking will be
recorded on the Hypothesis/Results sheets. After making their hypotheses,
students will begin layering the four colored liquids into a plastic cup one
color at a time. As soon as the colors mix, try a new combination.
Students will continue experimenting with different combinations until they
have layered the liquids in order from most dense to least dense. Record
the results. The students will pour all remaining liquid, in the proper
order, into an empty plastic cup. They will then hypothesize, ranking the
solids from least dense to most dense (they will weigh the solids in order
to make their hypotheses). After recording their hypotheses on the
Hypothesis/Results sheet, students will drop each of the solids, one at a
time, into the cup containing the layered liquids. Students will then
record the actual order of the solids by density and compare the differences
between their hypotheses and their actual results. They will then write a
paragraph on what they observed.

Performance Assessment: The student must complete the Hypothesis/Results sheet and observation paragraph with 100% accuracy. Density Results Activity Sheet Please hypothesize ranking the liquids from the heaviest to the lightest in density then write the actual ranking. Hypothesis Actual 1. ____________________ ____________________ 2. ____________________ ____________________ 3. ____________________ ____________________ 4. ____________________ ____________________ 5. ____________________ ____________________ Please hypothesize ranking the solids from the heaviest to the lightest in density then write the actual ranking. Hypothesis Actual 1. ____________________ ___________________ 2. ____________________ ___________________ 3. ____________________ ___________________ 4. ____________________ ___________________ 5. ____________________ ___________________ Please write a paragraph explaining your observations about your hypotheses compared to your actual test results.
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