The de Broglie wavelength is given by
$$\lambda\equiv\frac{h}{mv}$$
Now, if we have a small body, it's wavelength will be large when it is in motion. Similarly, a large body will have small wavelength. It can be seen from the equation. First of all tell me if I am right about these observations.
I was studying electron microscope and there was a sentence in it,
The fact that microscopic particles as the electron have extremely short de Broglie wavelengths has been put to practical use in many ultra modern devices.
It says that the electron, being a small particle, has a short de Broglie wavelength. But if we look at the equation, we see that small bodies will have large wavelength (provided that my observations about the equation are correct).
So my question is: why does a small particle as the electron has a small wavelength?
Best Answer
The statement:
is talking of the wavelength, which does not only depend on rest mass( your m is the relativistic mass) :
The electron gets to relativistic velocity much faster than heavier particles, and that makes the difference to the wavelength, the gamma.