Chapter 2, Problem 2.28P

a. Which 2+ ion has two 3d electrons? Which has eight 3d electrons?
b. Which is the more likely configuration for ${\text{Mn}}^{\text{2}+}:\left[\text{Ar}\right]\text{4}{s}^{\text{2}}\text{3}{d}^{\text{3}}$ or $\left[\text{Ar}\right]\text{3}{d}^{\text{5}}$ ?