Chapter 19

How big is a nanometer?

What is the main concept behind nanotechnology?

Give some examples of applications that exploit quantum mechanical size effects.

When particles get very small, the fraction of atoms at the surface gets large. Explain why this is so.

Give some examples of properties that are a result of surface effects.

What does a scanning tunneling microscope do? How does it work?

When and by whom was buckminsterfullerene discovered?

What are the formula and structure of buckminsterfullerene?

What are some applications of nanotubes?

What is Moore’s law?

A dust particle measures \(14 \times 10^{-6} \mathrm{~m}\) in diameter. What is its diameter in nanometers?

A red blood cell measures about \(7.8 \times 10^{-6} \mathrm{~m}\) in diameter. What is its diameter in nanometers?

Suppose you have two cubes, A and B. Cube A is composed of 512 smaller cubes \((8 \times 8 \times 8)\) and cube B is composed of 64 smaller cubes \((4 \times 4 \times 4)\). Calculate the fraction of small cubes on the surface of cubes A and B. Which cube has a higher fraction at the surface?

Suppose you have two cubes, A and B. Cube A is composed of 216 smaller cubes \((6 \times 6 \times 6)\) and cube B is composed of 27 smaller cubes \((3 \times 3 \times 3)\). Calculate the fraction of small cubes on the surface of cubes A and B. Which cube has a higher fraction at the surface?

If a nanotube measures \(10 \mathrm{~nm}\) in diameter, how many, laid side by side, would fit within the width of a human hair? A human hair is \(20 \times 10^{-6} \mathrm{~m}\) wide.

How many 10-nm-diameter nanotubes, laid side by side, would it take to make a line \(0.10 \mathrm{~mm}\) in width?

One of the criticisms often used against new technologies is that only the rich can afford them. Should this discourage the pursuit of nanotechnology? Why or why not?

Read the What If ... Value-Free Science box. Do you think scientists should have the freedom to pursue scientific knowledge regardless of its potential applications? Why or why not?

Write a short science fiction story involving a visit to the doctor in the year 2050 . Include nanotechnology in your story.