Question

Energy of an electron in the lowest energy state of the hydrogen atom is $ 13.6 \, eV $ . Find the energy needed to remove an electron from the fourth orbit.

• A. $ 13.6\, eV $
• B. $ 0.85\, eV $
• C. $ 10.2\, eV $
• D. $ 6.8\, eV $

Answer 1

Answer: (B)

Energy of an electron in $n^{th}$ state $=\frac{E_{1}}{n^{2}}$
In fourth state, $E_{4}=\frac{E_{1}}{\left(4\right)^{2}}$
$=\frac{13.6}{\left(4\right)^{2}}$
$=0.85\,eV$
Hence, the energy reguired to remove an electron from the fourth orbit is $0.85\,eV$