Chapter 9, Problem 89SAE

In multielectron atoms many of the periodic trends can be explained in terms of $Z_{ar}$ Consider the following statements and discuss whether or not the statement is true or false.
a. Electrons in a p orbital are more effective than electrons in the s orbitals in shielding other electrons from the nuclear charge.
b. $Z_{ar}$ for an electron in an s orbital is lower than that for an electron in a p orbital in the same shell.
c. $Z_{ar}$ is usually less than Z.
d. Electrons in orbitals having $\mathcal{l}=1$ penetrate better than those with $\mathcal{l}=2$ .
e. $Z_{ar}$ for the orbitals of the elements Na(3s), Mg(3s), Al(3p), P(3p), and S(3p) are in the order $Z_{an}\left(Na\right)<Z_{an}\left(Mg\right)>Z_{an}\left(AI\right)<Z_{an}\left(P\right)>Z_{an}\left(S\right).$