Chapter 6 The Structure of Atoms - 6-7 One More Electron Property: Electron Spin - Applying Chemical Principles - Page 244: 3

See the answer below.

$\lambda_1=589.00\ nm=0.58900\times10^{-6}\ m$ $\lambda_2=589.59\ nm=0.58959\times10^{-6}\ m$ $c=\lambda\times\nu$ $\nu_1=5.09\times10^{14}\ s^{-1}$ $\nu_2=5.08\times10^{14}\ s^{-1}$ $E=h\times\nu$ $E_1=3.37\times10^{-19}\ J$ $E_2=3.36\times10^{-19}\ J$ $E_1-E_2=3.375\times10^{-22}\ J$