Virtual Lessons

Lesson 2 of 2

Solid Lattices

This virtual lesson examines the different types of solid lattice structures and how the nature of bonding within each determines their physical properties.

The lesson opens by distinguishing between the main categories of lattice structure: giant ionic, giant metallic, giant covalent, simple molecular, and macromolecular. Each type arises from a different form of bonding and produces a distinct set of physical characteristics.

Particular focus is given to giant covalent structures, with four key examples examined in detail. Diamond is presented as a rigid three-dimensional network of carbon atoms with exceptional hardness and a very high melting point. Graphite is contrasted as a layered structure with delocalised electrons enabling electrical conductivity. Graphene is introduced as a single layer of graphite with remarkable strength and conductivity. Silicon(IV) oxide is examined as a giant covalent structure with no delocalised electrons, accounting for its insulating properties and high melting point.

Simple molecular structures are also covered, where discrete molecules are held together by weak intermolecular forces, resulting in low melting and boiling points. Macromolecular structures are discussed in terms of the characteristics they share with giant covalent lattices due to their extensively bonded networks.

The lesson brings together bonding theory and structural chemistry, developing the ability to predict and explain physical properties from the type of lattice and bonding present in a substance.