Lab
Date _________________
Density of Pennies Lab
Name ______________________
Section A B C
Objective: To quantify and analyze the change in the density of pennies minted before and after 1982.
Research Question: Is there a difference in density between pennies minted before and after 1982? Is
there a difference in the density of one versus several pennies?
Hypothesis: If pennies are minted before or after 1982, then the density…
If we find the density of one penny, and then the density of several, the density will…
Background Information: As a class, brainstorm key concepts and vocab necessary to understand this
lab. Sequence these ideas and connect them to one another in a complete paragraph.
Equipment:
Pennies (10 pre-1982 and 10 post-1982)
Triple beam balance
Graduated cylinder
Procedure:
1. Examine each penny to be sure you have 10 pre-1982 and 10 post-1982.
2. Mass one pre-1982 penny on the triple beam balance, and record the mass in a table in your
notebook.
3. Add another pre-1982 penny to the balance, and record the mass of both pennies together in
your notebook.
4. Continue adding and massing pre-1982 pennies until you have massed all 10 together.
5. Repeat for the post-1982 pennies.
6. Fill the graduated cylinder part way with water and record the initial volume.
7. Add one pre-1982 penny, and record the final volume.
8. Subtract the two volumes to find the volume of the penny by displacement.
9. Add a second penny to the graduated cylinder and record the new final volume.
10. Subtract the new final volume from the original initial volume to find the volume of two pennies
by displacement.
11. Continue adding pre-1982 pennies until you have found the volume of all 10 pennies together.
12. Repeat steps 6 through 11 for the post-1982 pennies.
13. Calculate the density of 1 through 10 pre- and post-1982 pennies, and record in your notebook.
14. Graph and analyze your data sets.
Data and Results:
1. Collect your data in an excellent table in your notebook.
2. Include a column in your table for calculating density from the mass and volume. Show the work
for one example calculation.
3. Graph your data, mass vs. volume. Your graph should have two lines: one for pre-1982 and one
for post-1982.
4. Write a one-sentence caption for your graph.
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Lab
Date _________________
Density of Pennies Lab
Name ______________________
Section A B C
Analysis: Write a paragraph in your notebook to describe your data. What are the trends of the graphs
(increasing, decreasing, constant)? What is the slope? Is the graph a line, a curve, a parabola? Do not
interpret your data. What do the lines represent? How are your two lines different? What do the
slopes of your lines represent? What does the y-intercept represent?
Conclusions: In several paragraphs of complete sentences in your notebook, answer the questions
below:
1. Is density an intensive or extensive property? How do you know? Give evidence from your data.
2. What element are pennies made of? This element has a density of 8.92 g/mL. How do your
densities (before 1982 and after 1982) compare with the density of the pure element? Why do
you think this is? (Hint: You might want to do a little internet search.)
3. How do you explain any difference in the density of the two groups?
4. Use the results of this lab to make a hypothesis about how the composition (make-up) of the two
groups of pennies is different. What do you think changed in 1982 (aside from density)? Why?
Assignment: You will write your first lab report about this lab. Please see the Guidelines for Writing Lab
Reports and Formal Lab Report – Grading Rubric. Your first draft is due ______________. A first draft
can be hand written (neatly!) or typed. Please come see Ms. Boiteau if you have questions or need any
help!!
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