• # question_answer The total energy of an electron in 4th orbit of hydrogen atom is A)  $-13.6\,\,eV$          B)  $-3.4\,\,eV$ C)  $-1.51\,\,eV$         D)  $-0.85\,\,eV$

For hydrogen atom ${{E}_{n}}=\frac{-13.6}{{{n}^{2}}}eV$ ${{E}_{n}}=\frac{-13.6}{{{4}^{2}}}eV$ $=-0.85\,eV$