Which ionic compound is expected to form from combining the following pairs of elements? (d) aluminum and oxygen.

Key Concepts

Ionic Bonding

Ionic bonding occurs when atoms transfer electrons to achieve full outer electron shells, resulting in the formation of charged ions. Typically, this happens between metals, which lose electrons and become positively charged cations, and nonmetals, which gain electrons to become negatively charged anions. The electrostatic attraction between these oppositely charged ions forms a stable ionic compound.

Aluminum Oxide Formation

When aluminum (a metal) reacts with oxygen (a nonmetal), it forms aluminum oxide (Al2O3). Aluminum has a +3 charge when it loses three electrons, while oxygen typically gains two electrons to achieve a -2 charge. To balance the charges in the compound, two aluminum ions combine with three oxide ions, resulting in the formula Al2O3, which is a common ionic compound.

Stoichiometry in Ionic Compounds

Stoichiometry involves the calculation of reactants and products in chemical reactions. In the context of ionic compounds, it helps determine the correct ratio of ions needed to form a neutral compound. For aluminum oxide, the stoichiometric ratio of aluminum to oxygen is 2:3, ensuring that the total positive and negative charges balance out to zero, which is essential for the stability of the ionic compound.