Introduction Density is the mass per unit volume of a substance by hcj

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									  Name: ______________________                              Group Members:
                         Density of Regularly Shaped Solids
  Introduction: Density is the mass per unit volume of a substance. It can be more informally
  thought of as a measure of just how tightly packed together the molecules of a substance are. In
  order to calculate density you need to know an objects mass and its volume. Mass can be
  determined by using a balance scale. Volume can be determined by using the displacement
  method or by measuring the dimensions of the substance if it has a regular shape. A regularly
  shaped object is a right prism, cube, cylinder, sphere, etc…

V = l·w·h                                                V = π·r2·h




  Part One: Aluminum (Al). Measure the mass and volume of six different pieces of aluminum.
                                             Dimensions
  Piece              Mass                                                    Volume Density
            Shape             Length     Width      Height       Radius
    #               (grams)                                                   (cm3)    (g/cm3)
                               (cm)       (cm)       (cm)         (cm)

    1


    2


    3


    4


    5


                                                                      Average Density =




                                                                                                     1
Name: ______________________                                Group Members:
                       Density of Regularly Shaped Solids
Part Two: Iron (Fe). Measure the mass and volume of six different pieces of iron.
                                     Dimensions
Piece             Mass                                         Volume Density
        Shape               Length      Width      Height
  #              (grams)                                         (cm3)     (g/cm3)
                             (cm)        (cm)        (cm)

  1


  2


  3


  4


  5


                                                       Average Density =



Part Three: Graphing. Construct two line graphs: one piece of graph paper for each data set,
one for Aluminum and one for Iron. Draw the best fit line for each data set (do not connect the
dots). Plot mass on the y-axis (vertical) and volume on the x-axis horizontal. The slope of the
line will represent the density.

Part 4: Calculations.
Determine the slope of each line. Recall that slope is the change in the y-axis (mass) over the
change in the x-axis (volume). The equation you may remember from math class is slope = (y2-
y1/x2-x1). Since, mass over volume = density. The slope of the line represents the density of the
substance. You should

Slope of Aluminum:




Slope of Iron:




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Name: ______________________                               Group Members:
                       Density of Regularly Shaped Solids
The known density of aluminum is 2.7 g/cm3. Calculate a percent deviation from the slope of
your aluminum line to the accepted density of aluminum (2.7 g/cm3).




The known density of iron is 7.8 g/cm3. Calculate a percent deviation from the slope of your iron
line to the accepted density of iron (7.8 g/cm3).




Part Five: Conclusion: On page 10 of the ESRT, “The Inferred Properties of Earth’s Interior” the
density of the different layers of the Earth is listed. Also, some information about the elemental
composition is given about the inner and outer cores. On page 1 of the ESRT, “The Average
Chemical Composition of the Earth’s Crust, Hydrosphere, and Troposphere,” more information
is given about the elemental composition of the crust. Using that information and the
information discussed/read in class, write a paragraph explaining the reason why the Earth is
organized the way it is. What is the relationship between density, elemental composition, and
the layers of the Earth?




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