Atomic hydrogen emits a bright line at wavelength 656 nm

CHEMISTRY · Subjective · CBSE · Chemistry · Structure of Atom · Structure of Atom

Problem

Atomic hydrogen emits a bright line at wavelength 656 nm. The energies of the hydrogen levels are given by

E_n=-\dfrac{13.6\,\text{eV}}{n^{2}}

. Determine the initial and final principal quantum numbers

n_\text{i}

and

n_\text{f}

that correspond to this emission line.