What does the Bonding, structure and properties module cover?

This module covers WJEC Unit 2 topic 2.1. It explains the three main types of bonding (ionic, covalent and metallic), the four structure types (giant ionic, simple molecular, giant covalent and metallic), how to draw dot-and-cross diagrams, the special carbon structures diamond and graphite, what alloys are and why they are harder than pure metals, and how to deduce the bonding in a substance from its properties.

Which unit and paper assess this module?

These topics are part of Unit 2 (Chemical bonding, application of chemical reactions and organic chemistry), assessed on the Unit 2 written paper. The paper is 1 hour 45 minutes, worth 80 marks and 45 percent of the qualification, sat at Foundation or Higher tier.

What is the most common exam skill in this module?

Linking structure to properties. You are very often given the melting point, electrical conductivity and state of a substance and asked to deduce its type of bonding, or given the bonding and asked to explain a property. Learn the fingerprint of each structure type.

What is the difference between ionic and covalent bonding?

Ionic bonding is between a metal and a non-metal and involves the transfer of electrons to form charged ions held in a giant lattice. Covalent bonding is between non-metals and involves the sharing of pairs of electrons to form molecules or giant covalent structures.

How should I revise this module?

Learn the four structure types and their typical properties as a table: ionic, simple molecular, giant covalent and metallic. Practise dot-and-cross diagrams for ionic compounds and simple molecules. Memorise the diamond and graphite structures and why their properties differ, and learn why alloys are harder than pure metals. Then practise deducing bonding from melting point and conductivity using WJEC past papers.

WalesChemistry

WJEC GCSE Chemistry: Bonding, structure and properties (Unit 2.1) overview

An overview of the Bonding, structure and properties module in WJEC GCSE Chemistry (topic 2.1), mapping ionic, covalent, giant covalent and metallic bonding, alloys, and how to deduce bonding from the properties of a substance.

Generated by Claude Opus 4.87 min readWJEC Chemistry 2.1Updated 2026-06-14

Reviewed by: AI editorial process; not yet individually human-reviewed

Jump to a section

The topics in this module
How this module fits the exam
How to study this module

The Bonding, structure and properties module covers WJEC Unit 2 topic 2.1. It explains how atoms join together by ionic, covalent and metallic bonding, the four kinds of structure that result, and how those structures explain the properties we can measure. This is one of the most heavily examined parts of the course because almost every property question comes back to bonding. This page maps the module and links to a focused answer page for each part.

The topics in this module

Ionic bonding: Electron transfer between metals and non-metals, dot-and-cross diagrams, the giant ionic lattice and its properties. See Ionic bonding.
Covalent bonding: Shared pairs of electrons between non-metals, dot-and-cross diagrams for simple molecules, and why simple molecular substances have low melting points and do not conduct. See Covalent bonding.
Giant covalent structures: Diamond and graphite, and how their different bonding explains their very different properties. See Giant covalent structures.
Metallic bonding and alloys: Positive ions in a sea of delocalised electrons, how this explains conductivity and malleability, and why alloys are harder than pure metals. See Metallic bonding and alloys.
Structure and properties: Bringing the four structure types together and deducing bonding from melting point, conductivity and state. See Structure and properties.

How this module fits the exam

These topics sit in Unit 2, assessed on the Unit 2 written paper (1 hour 45 minutes, 80 marks, 45%). Questions test dot-and-cross diagrams, explanations of properties in terms of structure, and the deduction of bonding from data.

How to study this module

Build a structure table. For ionic, simple molecular, giant covalent and metallic, list melting point, conductivity, hardness and solubility.
Practise dot-and-cross. Draw ionic transfers and covalent shared pairs until they are automatic.
Master diamond and graphite. Four bonds versus three, and the free electron in graphite.
Learn the alloy explanation. Different-sized atoms disrupt the layers so they cannot slide.
Deduce bonding from data. Use melting point first, then conductivity, to identify a structure.

Then test yourself with the module quiz.

Sources & how we know this

WJEC GCSE Chemistry specification (from 2016) — WJEC (2016)