How Thick is Aluminum Foil?

Measurements, Significant Figures, and Density

The first unit in chemistry class includes measurements and general number sense. There are several labs that we do and review as a class to get the idea of significant figures.  One of these labs involves determining the thickness of aluminum foil. First the students had a warm-up as the bell-ringer:

Class Warm-up:  Density

 Remember the relationships:
 Density = mass/Volume and  Volume = length x width x height.

These two equations can be combined to yield:
D = -----------------------------
                l x w x h
If you wanted to know how “tall” something is, you would solve for h, as in the equation following:

 h = -----------------------------
                D x l  x w

Solve the following problems:1.       What is the volume of a block that is 8.20 cm long, 2.25 cm wide, and 1.00 cm high?
2.       If the density of a substance is 0.525 g/cm3, and the volume of a sample is 18.25 cm3, what is the mass of the sample?
3.       A piece of paper is known to have an area of 595.5 cm2 and a mass of 4.589 g. What is the thickness (height) of this paper, if paper has a density of 0.72 g/cm3?

Class Activity: Foiled

Pre-cut squares of three types of aluminum foil were set out, and students were directed to take the measurements needed to calculate the thickness, based on the warm-up calculation above. The density of aluminum was given to the students as 2.70 g/cm3. I tried to cut the squares so that they were not an exact centimeter size, so that students would need to read the mm lines and estimate a "between the lines" digit.
Foil squares origami envelope
Pre-cut squares of foil saves time.
I made quick origami envelopes to store them in. 

foldable origami envelope
Origami pocket directions

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