Ionic Bonding

Summary and Exam Tips for Ionic Bonding

Ionic Bonding is a subtopic of Principles of Chemistry, which falls under the subject Chemistry in the Edexcel IGCSE curriculum. Ionic bonding involves the formation of ions, which are atoms or groups of atoms with a positive or negative charge. Cations are positive ions formed when an atom loses electrons, such as Sodium ($\text{Na}^+$), while anions are negative ions formed when an atom gains electrons, like Chlorine ($\text{Cl}^-$).

Ionic bonds are created through strong electrostatic attractions between these oppositely charged ions. Typically, this occurs between elements from Group I and Group VII of the periodic table, where a Group I element loses an electron to form a $+1$ ion, and a Group VII element gains an electron to form a $-1$ ion, as seen in Sodium Chloride ($\text{NaCl}$). Similarly, ionic bonds form between metallic and non-metallic elements, with metals losing electrons to become positively charged and non-metals gaining electrons to become negatively charged.

The lattice structure of ionic compounds, such as $\text{NaCl}$, is characterized by a regular arrangement of alternating positive and negative ions held together by strong electrostatic forces. These forces require significant energy to overcome, contributing to the stability of ionic compounds.

Exam Tips

• When drawing dot and cross diagrams, focus on showing the electron's outer shell.
• Remember to draw ionic compounds with ions separated, each enclosed in square brackets with their respective charge.
• Understand that molten or aqueous ionic compounds can conduct electricity due to free ions, while metals conduct electricity through free electrons.
• Practice identifying and explaining the formation of ionic bonds between Group I and Group VII elements, as well as between metallic and non-metallic elements.
• Familiarize yourself with the concept of lattice structures and the energy required to overcome the electrostatic forces within ionic compounds.