Question

The electron microscope can "see" smaller detail than an optical microscope because the wavelength of the electron can be made much shorter than visible light. Now consider the possibility of a proton microscope. By what potential difference (in volts) must A) a proton and B) an electron be accelerated to give a wavelength of 5x10^-12m? Can you think of a reason why we have electron microscopes, but do not commonly have proton microscopes?

Answer 1

So the important concept here is of de-Broglie wavelength and the hypothesis.

Now,

. So plugging in the values one gets, .

Reason for electron microscope is source. Electron sources are readily available than proton source, and the workfunction of the material is much lower. Typically few ~