Lab 5 : Diameter of an atom in which we will attempt to determine how small is small.
Data Table
Volume of 50 drops
Trial 1 _________
Trial 2 _________
Width of oil spill ____________
Length of oil spill ____________
Lab Analysis: Please show, explain and label all work and calculations. Round answers to the proper number of
significant digits. Answer question in complete sentences that incorporate the question.
1. Using the values from your data table, calculate the average volume of a single oil drop in mL.
2. Assume that the oil drop formed a cylindrical ellipse. (The equation for the volume of a cylindrical ellipse is
v =πabt where a is the minor radius, b is the major radius, and t is the thickness of the oil film.) Calculate the
thickness of the oil film.
4. The thickness of that oil film is the length of a molecule which contains 19 carbon atoms. Calculate the
diameter of 1 of these carbon atoms.
5. If the accepted diameter of a carbon atom is 1.4 x 10-8 cm, calculate your percent error.
% error = ((accepted value - experimental value) / accepted value ) * 100
6. For each of the following possible errors, discuss what effect it would have had on your calculated diameter and
explain why.
a. If the oil was unable to spread out completely because it hit the sides of the tray.
b. If you placed too much lycopodium powder on the surface of the water and the resistance of the powder
didn't let the oil film spread out as much as it could have.
Conclusion: Briefly restate what procedure was followed, what results were obtained and the percent error in
those results. You should address the original purpose of the lab.
Sources of Error: You should address SYSTEMATIC errors (one that were not made by people, but by the design
of the lab) and Human errors. You need to be specific.