What amount of energy (in eV) should be added to an electron to reduce its de-Broglie its de-Broglie wavelength from 100 to 50 pm? Given h = 6.62 × 10 − 34 J s , m e = 9.1 × 10 − 31 k g ℎ = 6.62 × 10⁻³⁴ , Js, Me = 9.1 × 10⁻³¹ Kg.