GCSE Chemistry: Bonding - Ionic, Covalent and Metallic Guide

Ionic bonding

Ionic bonding occurs between metals and non-metals, where electrons are transferred to form oppositely charged ions that are strongly attracted to each other, forming a giant ionic lattice.

Covalent bonding

Covalent bonding occurs between non-metals, where atoms share pairs of electrons. This can form small molecules (like water) or giant covalent structures (like diamond) with very different properties.

Metallic bonding

Metallic bonding involves a lattice of positive metal ions surrounded by a "sea" of delocalised electrons, which explains why metals conduct electricity and heat well, and can be bent and shaped.

Linking bonding to properties

Ionic compounds have high melting points and conduct electricity when molten or dissolved. Simple covalent molecules have low melting points and don't conduct electricity. Giant covalent structures and metals typically have high melting points.

Common mistakes

• Confusing ionic bonding (electron transfer) with covalent bonding (electron sharing).
• Forgetting ionic compounds only conduct electricity when molten or in solution, not as a solid.
• Assuming all covalent substances have low melting points, forgetting giant covalent structures like diamond.