Chapter 7, Problem 25QP

The electron configuration of C is $1s^{2}2s^{2}2P^2$. (a) If each core electron (i.e., the 1s electrons) were totally effective in shielding the valence electrons (i.e., the 2s and 2p electrons) from the nucleus and the valence electrons did not shield one another, what would be the shielding constant $\left(\sigma \right)$ and the effective nuclear charge ( $Z_{\text{eff}}$) for the 2s and 2p electrons? (b) In reality, the shielding constants for the 2s and 2p electrons in C are slightly different. They are 2.78 and 2.86. respectively. Calculate $Z_{\text{eff}}$ for these electrons, and explain the differences from the values you determined in part (a).