Giant Covalent Structure

Key Stage 4

Meaning

Giant covalent structures are very large molecules in which all the atoms are held to one another by covalent bonds.

About Giant Covalent Structures

Giant covalent structures are molecules made of a large number of non-metal atoms joined by covalent bonds.

The atoms in a giant covalent structure are arranged in a regular lattice (a repeating pattern of elements.

Examples

Diamond is a giant covalent structure where each Carbon atom has 4 bonds with adjacent atoms.	Graphite has a giant covalent structure with each Carbon atom has 3 bonds with adjacent atoms in a layer with loose bonds between the layers.	Graphene has a giant covalent structure with each Carbon atom has 3 bonds with adjacent atoms forming a layer that is one atom thick.	Silica is made of Silicon and Oxygen atoms in a lattice forming a giant covalent structure.

Bulk Properties

Giant Covalent Structures usually have very high melting points due to the strong chemical bonds between adjacent atoms.

Giant Covalent Structures may have good or poor electrical conductors depending on whether there are any electrons free to move between atoms.

Diamond is a poor electrical conductor because all the electrons are shared by adjacent atoms so none are free to move between atoms.

Graphite and graphene are good electrical conductors because the Carbon atoms only form 3 bonds with adjacent atoms allowing a spare electron in each atom to move freely around the molecule.