Chapter 3, Problem 18E

Determine the number of protons and electrons in each of the following ions:

$\begin{array}{l}\text{a}{\text{. Mg}}^{\text{2+}}\hfill \\ \text{b}{\text{. Se}}^{\text{2-}}\hfill \\ \text{c}{\text{. O}}^{\text{2-}}\hfill \\ \text{d}{\text{. Fe}}^{\text{3+}}\hfill \end{array}$