Electrons Can Be Used to Probe the Arrangement of Atoms

Multiple Choice

Electrons can be used to probe the arrangement of atoms on a solid surface if the wavelength of the electrons is comparable with the spacing between the atoms.Which of the following electron velocities would be appropriate for use in this application if the atoms are separated by 0.320 nm?

A) 1.24 × 10³ m/s
B) 8.06 × 10³ m/s
C) 2.27 × 10⁶ m/s
D) 4.41 × 10⁶ m/s
E) 3.00 × 10⁸ m/s