Just How Thick Is Aluminum Foil Anyway???
To determine the thickness of a sheet of aluminum foil from the density of
Class: Each group of 2 or 3:
aluminum metal shavings balance
variety of brands of aluminum foil metric ruler
demonstration vernier caliper vernier caliper
rolling pin rectangular aluminum metal slab
graduated cylinder, 50 mL rectangular piece of aluminum foil
1. Pass 3 or 4 different brands of aluminum foil in boxes (e.g. Reynolds
Heavy Duty, Reynolds Aluminum Foil, Heritage House Heavy Duty, generic aluminum
foil, etc.) around for students to examine. Ask in what ways the brands differ
from each other. What is meant by "heavy duty"? Net weight and the foil
thickness are not printed on the boxes. Ask students for suggestions for
2. Review the use of a vernier caliper using the large demonstration model
and boxes of the foil. Ask students to come up and read the calipers. Would
the calipers be useful in finding the foil thickness? They should explain.
3. Review the concept of density which relates the mass of the substance to
its volume. What is the mathematical formula for density? Does density depend
on the shape of the solid aluminum? Show students aluminum shavings and a
rectangular aluminum slab.
4. Have students test out their answer for density by finding the density of
a rectangular aluminum slab at their lab station, recording their data and
calculations in their lab notebook and then writing their experimentally
determined density on the board. Determine the class average density for the
aluminum slabs and compare it to the experimental value for the aluminum
shavings that they determined in an earlier lab. Have a student look up the
theoretical density for aluminum in the CRC Handbook of Chemistry and Physics.
5. Now have the students experimentally find the thickness of their piece of
aluminum foil, recording data and calculations in their notebooks. All groups
have the same brand and thickness of foil. Have a rolling pin and graduated
cylinder available for students wishing to verify the volume by water
displacement. Record their answers on the board and calculate the average.
6. Students write answers for the following questions in their lab report:
A. What precautions must be taken when massing the foil?
B. Why won't water displacement work well for finding the foil's volume?
C. You are given a chunk of shiny silver-colored metal. How can you
tell whether the metal is silver, platinum or aluminum?
D. Describe how the thickness of the metal in the side of an aluminum
pop can can be determined.