Virtual Lessons

Lesson 1 of 2

Ionic Bonding

This virtual lesson introduces the nature of ionic bonding, exploring how ions form, how they are represented, and the structural and physical consequences of ionic lattices.

The lesson opens by examining the evidence for the existence of ions, including the physical properties of ionic compounds, electron density maps, and the migration of ions. Ion formation through the loss or gain of electrons is then covered, with dot-and-cross diagrams used to show the electron arrangements in both cations and anions.

The nature of ionic bonding is then established, defined as the result of strong net electrostatic attraction between oppositely charged ions arranged in giant ionic lattices. The influence of ionic radius and ionic charge on the strength of ionic bonding is examined, alongside trends in ionic radii down a group and across a set of isoelectronic ions, including N3- to Al3+.

The lesson then explores the concept of polarisation as applied to ions, explaining that the polarising power of a cation depends on its radius and charge, and that the polarisability of an anion similarly depends on its radius and charge. This introduces the idea that ionic bonding exists on a spectrum, with highly polarised ions exhibiting increasing covalent character.

The lesson establishes the foundational understanding of ionic structures and bonding principles needed to compare ionic compounds with covalent and metallic bonding in subsequent lessons.