Problem 6 - Chemistry A Guided Inquiry

Question

a) What is the charge on the cation formed from \(\mathrm{Mg}\) ? b) What is the charge on the anion formed from \(\mathrm{O}\) (called the oxide ion)? c) What is the formula for the ionic compound containing magnesium ions and oxide ions?

Step-by-Step Solution

Answer

a) The charge on the Mg cation is +2. b) The charge on the O anion is -2. c) The formula for the ionic compound containing magnesium ions and oxide ions is \(MgO\).

Step 1: Identify Charge of Mg Cation

Mg (Magnesium) is in group 2 of the periodic table. Elements in group 2 form cations with a charge of +2 as they tend to lose 2 electrons to achieve a stable electron configuration. Therefore, the cation formed from Mg has a charge of +2.

Step 2: Identify Charge of O Anion

O (Oxygen) belongs to group 16 of the periodic table. Elements in group 16 form anions with a charge of -2, as they tends to gain 2 electrons to achieve a stable electron configuration. Therefore, the anion formed from O has a charge of -2.

Step 3: Formulate the Ionic Compound

In ionic compounds, the total positive charge and the total negative charge must be equal. The Mg cation has a charge of +2 and the O anion has a charge of -2. Therefore, the compound will be formed by one Mg cation and one O anion resulting in the compound formula as \(MgO\).