Answer:
λ = 6.19*10^-11 m
Explanation:
Given that
Kinetic Energy, K = 390 keV
Mass of electron, m = 9.1*10^-31 kg
Planck's constant, h = 6.6*10^-34
To find the De Broglie's wavelength, we use this formula
λ = h / √(2mk), where λ is the wavelength were looking for.
Now we substitute the values into the equation
λ = 6.6*10^-34 / √(2 * 9.1*10^-31 * 390 * 1.6*10^-19)
λ = 6.6*10^-34 / √1.136*10^-46
λ = 6.6*10^-34 / 1.066*10^-23
λ = 6.19*10^-11 m
