## Question

calculate the wavelength of an electron of mass 9.1×10^{-31 }kg moving with a velocity of 2.0×10^{6} m/s. Plancks constant, h = 6.63 x 10^{-34}Js.

## Answer

Mass of electron, M_{e} = 9.1×10^{-31 }kg, v = 2.0×10^{6} m/s, and h = 6.63 x 10^{-34}Js.

From De Broglie, **λ** = h / (M_{e}v) = (6.63 x 10^{-34}) / (9.1×10^{-31} x 2.0×10^{6}) = 3.64×10^{-10} m

Therefore, the wavelength of the electron is 3.64×10^{-10} meters.