Density of Aluminum
Graphing Activity
Name_____________________________
Partner Name_____________________
Density is a property that can be used to identify a substance just as color can be used to identify
substances. Example, copper is shiny reddish brown. Each substance has its own unique value of density.
To identify the substance, its mass and volume must first be determined and then its density can be
calculated using:
Density = Mass/Volume
The mass is determined by using a balance and reading the value to the nearest whole number in grams.
The volume of the cylinder is calculated by using:
Volume = X r2 X L


r = radius of the cylinder (half the diameter)
L = length of the cylinder
 = the number 3.14
Density is used in industry and forensics to determine the identity of unknown substances
Materials:


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Balance
Ruler
12 aluminum cylinder specimens
Procedure:
1. Working with a partner, obtain from your teacher one of the lettered specimens. Write data
collected in the correct row in your data table.
2. Measure the length and diameter to the nearest tenth of a centimeter. Record the
measurements in the data table. Be sure to include units.
3. Calculate the volume using the formula from above and record it in the data table. Be sure to
divide the diameter in half to determine the radius. Be sure to include units.
4. Using a balance determine the mass of the cube to the nearest whole number in grams. Record
the mass in the data table. Be sure to include units.
5. Calculate the density using the formula listed above and the mass and volume from the data
table. Record the result in the data table and include units.
Data Table
Sample
Diameter
cm
Length
cm
Radius
cm
Volume
cm3
Mass
g
Density
g/cm3
A
.
B
.
C
.
D
.
E
.
F
.
G
.
H
.
I
.
J
.
K
.
L
.
Graph
Using a piece of paper supplied by your teacher, graph the mass and volume for each point in the data
table. Volume is the x-axis (independent variable) and mass is the y-axis (dependent). Label each axis
and draw the best-fit straight line for your graph using a pencil and straightedge. Follow your teacher’s
instructions for the graph. (If there is a point far from the pattern of the other points then this point
should be measured and calculated again.)
Questions
Using the graph and data, answer the following questions:
1. A best-fit line is one that represents the pattern of the data. The line should go through (0,0).
Explain why.
2. All the points may not fall on the straight line. Explain why.