Energy of an electron in nth orbit of hydrogen atom is ≤ft(k=1/(4 π ε…

$-\frac{2 \pi^2 k^2 m e^4}{n^2 h^2}$

$-\frac{4 \pi^2 m k e^2}{n^2 h^2}$

$-\frac{n^2 h^2}{2 \pi k m e^4}$

$-\frac{n^2 h^2}{4 \pi^2 k m e^2}$