The Thickness of Aluminum Foil: Student Version

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Name____________________________________ Hr_______ Date_______________

Objective: Determine the thickness of aluminum foil using mass, length, and width measurements as well as the density of Al.

Materials:

• rectangular piece of aluminum foil
• balance
• centimeter ruler

Find the mass of your aluminum foil. (mass = __________ grams)

Measure the length and width of your aluminum foil.

(Remember to record all numbers that you know for sure plus one estimated digit.) (length = ______ cm and width = _________ cm)

Calculate the volume of your aluminum piece.

Use the density formula, D = mass/volume for this. Solving for V gives

V = mass / density

(Volume of foil = ________ cubic centimeters = ______ ml)

Note: 1 cubic centimeter occupies the same volume as 1 milliliter.

Round your answer to match the origincal measurement that had the fewest significant digits.

(Volume after rounding for significant digits = _________________ ml)

Calculate the thickness of your aluminum.

Use the formula of a box, V = length x width x height

solve the formula for height, which represents the thickness of the aluminum foil in cm.

(h = _______________ cm thick)

Round your answer to match the original measurement with the fewest significant digits.

(Thickness after rounding significant digits = __________________ cm.)

1. Why couldn't you use a centimeter ruler to measure the thickness of the aluminum foil?
2. What would you say to a person that recorded the length of her aluminum foil as 3.4575 cm after measuring with a ruler marked to the nearest millimeter?
3. Why do scientists use significant figures when taking measurements and doing calculations in the laboratory?
4. When is one time that a number is exempt from the use of significant digits?
5. Write a one paragraph summary of this activity and your findings.

Some places that manufacture paper and aluminum foil actually test the thickness of their product by shining a beam of radioactive particles at it. The more particles that pass through, the thinner the paper. This is how = a simple geiger counter or radiation detector can be turned into a quality control device. Who knew?!