Pearson Edexcel International GCSE Chemistry · specification 4CH1 · Paper 2 | Whole paper: All content including bold C statements · Free · no account needed
1(g) Covalent bonding (4CH1 specification)
Shared electron pairs, and the crucial distinction between the strong bonds inside a molecule and the weak forces between molecules.
Learn it on Incandio
The 2 Incandio pages that teach this — each explained in full, then proved in marked questions, taught back to an AI pupil and defended in a debate. Completely free.
- Why Substances Conduct — the Four Structures Compared — One test applied to every structure in the topic, and the two words electrolysis is built on.
- Electrolysis — Using a current to pull a compound apart, and writing down what happens at each electrode.
The teaching route this belongs to: Topic 1 · Principles of chemistry (Chemistry) — the lessons in order, with every gate.
Specification coverage
Topic 1 Principles of chemistry (g) Covalent bonding — statements 1.55–1.60C (includes bold C statements assessed on Paper 2 only)
Assessment objectives: AO1, AO2. Suggested learning time: 60 minutes.
Required knowledge
- The formation of covalent bonds by shared electron pairs
- Dot-and-cross diagrams for simple molecules
- The properties of simple molecular substances: low melting and boiling points, poor conduction
- Giant covalent structures: diamond, graphite and silicon dioxide, and their properties
- Bold C statements: the relationship between structure and properties in greater depth
Required skills
- Distinguish intramolecular bonds from intermolecular forces in an explanation
- Explain the properties of diamond and graphite from their structures
How it is examined
- Multiple-choice and short-answer recall
- Application of the content to an unfamiliar context
- Extended open-response, marked on the quality of a connected explanation
Common mistakes
- Saying simple molecular substances melt at low temperatures 'because the covalent bonds are weak'. The covalent bonds are strong; the forces BETWEEN molecules are weak, and those are what melting overcomes. This is the single most-penalised error in the topic.
- Saying graphite conducts because it has free ions. It has delocalised electrons.
- Forgetting that each carbon in graphite bonds to three others, leaving one electron delocalised.
This page maps the specification. The pages above teach it, and the Chemistry lessons hold the whole course — completely free.