```DensitiesEllice M. Norman               Teachers Academy for Math and Science                               10 West 35th Street                               Chicago IL 60616                               (312)808-0100Objectives:     This activity will help the middle school student understand the concept ofdensity.  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                                              PaperclipsMolasses                                            CorksOil                                                 Pieces of a candleWater                                               WoodchipsRed and blue food colorings                         Yellow clayPickling salt                                       Density Results SheetsPlastic cups (6oz.)                                 Medicine droppersStrategies: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.  ____________________                       ___________________

compared to your actual test results.

```