In 1924,de Broglie proposed that particle acts as a wave and wave acts as a particle. Davisson and Germer experimentally confirmed the wave nature of electron.They showed that electrons are diffracted from metallic crystal in the same manner as x-rays and other wave.Hence electrons show wave like properties.J.J Thomson while measuring e/m of electron showed that electron is a particle.Thus electron shows particle like nature as well as wave like nature.An electron moving with velocity ‘v’ has momentum given by:
P=mv ——————-(1)
Since the momentum of a photon is given by the relation:
P = h/λ
λ = h/p
λ =h/mv ——-(2)
Where λ is the wavelength associated with particle wave.Hence an electron can be considered to be a particle and it can be considered to be a wave.