Hi, I'm studying the wave nature of particles. My book says that the de broglie wavelength of an electron is h / momentum, or h / (mv). I also have that E = hf = momentum2/(2m) = 1/2 mv2. I know that for a photon the frequency is speed of light / wavelength. I'm wondering why the frequency for an electron is not 1/ wavelength. Is there any equation relating f and lambda for a particle (electron)? Thanks for any help.