Predict the chemical formula of the ionic compound formed between the following pairs of elements: (b) Mg and O (c) Zn and Cl

Verified step by step guidance

1. Step 1: Identify the charges of the ions. Magnesium (Mg) is in group 2 of the periodic table and forms a +2 ion. Oxygen (O) is in group 16 and forms a -2 ion.
2. Step 2: Write the ions side by side, with the cation (positive ion) first. This gives us Mg^2+ and O^2-.
3. Step 3: The charges on the ions must balance, meaning the total positive charge must equal the total negative charge. In this case, the charges already balance, so we don't need to add any subscripts.
4. Step 4: Write the formula using the symbols of the ions. The cation is always written first. This gives us MgO.
5. Step 5: Check your work. The charges should balance to zero. In this case, the +2 charge on the Mg ion balances with the -2 charge on the O ion, so our formula is correct.

Key Concepts

Ionic Bonding

Ionic bonding occurs when atoms transfer electrons to achieve full outer electron shells, resulting in the formation of charged ions. Metals, like magnesium (Mg), tend to lose electrons and form cations, while nonmetals, like oxygen (O), gain electrons to form anions. The electrostatic attraction between these oppositely charged ions leads to the formation of ionic compounds.

Charge of Ions

The charge of ions is determined by the number of electrons lost or gained by an atom. Magnesium typically loses two electrons to form a Mg²⁺ ion, while oxygen gains two electrons to form an O²⁻ ion. Understanding the charges of the ions involved is crucial for predicting the correct ratio of ions in the resulting ionic compound.

Empirical Formula

The empirical formula of an ionic compound represents the simplest whole-number ratio of the ions present. For magnesium and oxygen, the Mg²⁺ and O²⁻ ions combine in a 1:1 ratio to form the compound magnesium oxide (MgO). This formula reflects the balance of charges, ensuring that the overall compound is electrically neutral.