Question

What is the de Broglie wavelength of a 5.0-eV electron?

Answer 1

E=5eV=8•10⁻¹⁹ J
λ=h/p = h/sqrt(2mE) =
=6.63•10⁻³⁴/sqrt(2•9.1•10⁻³¹•8•10⁻¹⁹)=5.5•10⁻¹⁰ m