Question

The seeing ability, or resolution, of radiation is determined by its wavelength. If size of an atom is
of the order of 0.1 nm, how fast must an electron travel to have a wavelength small enough to “see” an
atom?

Answer 1

The electron wavelength (h/mv)should be comparable to the atom size, or less.

h is Planck's constant. m is the electron mass.

Use the relationship above to get the required minimum electron momentum.

Divide that by the electrobn mass for the thew requkired electron speed.