Question

What is the energy needed to raise an electron in the hydrogen atom from the second energy level to the third energy level ?

Answer 1

$\Delta E=|E_{2}-E_{3}|=|\frac{E_{1}}{4}-\frac{E_{1}}{9}|=|\frac{-13.9eV}{4}-\frac{-13.9eV}{9}|=\\\\ =|-3.475eV+1.544eV|=|-1,931eV|=1.931eV$

 1eV --------- is ----------- 1.6*10⁻¹⁹J
1.931eV ---- is -----------  x

x = [1.931eV*1.6*10⁻¹⁹J]/1eV ≈ 3,1*10⁻¹⁹J

ANSWER E