In a chemical compound, would you expect an oxide ion to be joined with one atom of calcium or one atom of potassium? Why?
To determine whether an oxide ion (O2-) would be joined with one atom of calcium (Ca) or one atom of potassium (K), we need to consider their respective chemical properties.
First, we need to know the charges of the ions involved. The oxide ion (O2-) has a charge of -2 because oxygen tends to gain two electrons to achieve a stable electronic configuration. Calcium (Ca) has a charge of +2 since it tends to lose two electrons to achieve stability, and potassium (K) has a charge of +1 as it loses one electron.
Now, we can use the concept of ionic bonding and the rule of charge neutrality to predict the combination. In an ionic compound, the total positive charge of the cations must balance the total negative charge of the anions.
Since the oxide ion (O2-) carries a charge of -2, it needs to combine with a cation with a charge of +2 to achieve charge neutrality. Since calcium (Ca) has a charge of +2, it can form an ionic bond with the oxide ion, resulting in the compound calcium oxide (CaO).
On the other hand, potassium (K) only has a charge of +1, which wouldn't be sufficient to balance the -2 charge of the oxide ion. Therefore, the oxide ion would not typically be joined with an atom of potassium.
In conclusion, an oxide ion is more likely to be joined with one atom of calcium instead of one atom of potassium due to the charge requirements for charge neutrality in an ionic compound.
an oxide ion will take on two electrons
calcium has two valence electrons
potassium has one valence electron