a. The graph of ionization energy versus atomic number for the elements Na through A...

a. The graph of ionization energy versus atomic number for the elements Na through Ar ( Figure 2.13 ) shows maxima at Mg and P and minima at Al and S. Explain these maxima and minima.

b. The graph of electron affinity versus atomic number for the elements Na through Ar ( Figure 2.13 ) also shows maxima and minima, but shifted by one element in comparison with the ionization energy graph. Why are the maxima and minima shifted in this way?

Reference of figure 2.13