## Chemistry: The Central Science (13th Edition)

In order to fill this table, we have to balance charges on anions and cations. For example: For $K^{+}$ and $OH^{-}$ the charges are balanced. Thus, the chemical formula is $KOH$ For $K^{+}$ and $CO_{3}^ {2-}$. We need to balance charges. Therefore, we need two atoms of $K^{+}$ Ions. Thus, the chemical formula is $K_{2}CO_{3}$ For $Mg^{2-}$ and $PO_{4}^{3-}$, we need three ions of $Mg^{2-}$ ($3\times +2 = +6$) and two ions of $PO_{4}^{3-}$ ($2 \times -3 = -6$) The rest of the table is filled in this way.