If the diameter of a carbon atom is approximately 140 pm, how many carbon atoms lined up side to side would span a pencil lead with a diameter of about 0.7 mm?

Question

Quizplus · Accepted Answer

The diameter of a carbon atom is 140 pm = 1.4 x 10^-10 m. The diameter of the pencil lead is 0.7 mm = 7 x 10^-4 m. So, the number of carbon atoms that can be lined up side by side is (7 x 10^-4 m) / (1.4 x 10^-10 m) = 5 x 10^6 atoms.

If the Diameter of a Carbon Atom Is Approximately 140