In a chemical compound, would you expect an oxide ion to be joined with one atom of calcium or one atom of potassium? Why?
In a chemical compound, an oxide ion (O2-) would be expected to be joined with one atom of calcium (Ca).
This is because calcium (Ca) belongs to group 2 of the periodic table and readily forms cations with a charge of +2. Since the oxide ion has a charge of -2, it requires two calcium ions to balance the charges. The formula for the compound formed would be CaO.
On the other hand, potassium (K) belongs to group 1 of the periodic table and forms cations with a charge of +1. Therefore, it would not be a suitable match for the oxide ion, as it cannot provide the necessary charge balance.
To determine whether an oxide ion would be joined with one atom of calcium or one atom of potassium in a chemical compound, we need to analyze the charges and valence electrons of each element involved.
An oxide ion (O2-) has a charge of -2, indicating that it has gained 2 electrons to achieve stability. Calcium (Ca) has a charge of +2 as a cation, meaning it has lost 2 electrons to achieve stability. Potassium (K) has a charge of +1 as a cation, indicating that it has lost 1 electron to achieve stability.
In ionic compounds, elements form bonds in such a way that their charges balance out. The charges of the elements are usually directly related to the number of valence electrons they have.
Calcium has 2 valence electrons and typically forms a bond by giving away these electrons, resulting in a cation with a charge of +2. To balance its charge, it can form a bond with two oxide ions (each with a charge of -2), as the +2 and -2 charges will neutralize each other.
Potassium has 1 valence electron and typically forms a bond by losing this electron, resulting in a cation with a charge of +1. To balance its charge, it can form a bond with one oxide ion (with a charge of -2), as the +1 and -2 charges will neutralize each other.
Therefore, based on the charges and valence electrons, an oxide ion is expected to be joined with one atom of calcium, since calcium has a charge that matches the charge of the oxide ion. Potassium would not be able to fully balance the charge of an oxide ion with its +1 charge.