Chapter 5, Problem 13P

Spectroscopic studies show that Li can have electrons in its 1s, 2s, and 2p Hartree orbitals, and that $Z_{\text{eff}}\left(\text{2}s\right)=\text{1}.\text{28}$ for the $1s^{2}2s^1$ configuration. Estimate the energy of the 2s orbital of Li. Calculate the average distance of the electron from the nucleus in the 2s orbital of Li.