This topic summary covers Knowledge Organiser: Covalent Bonding within Covalent Bonding for GCSE Chemistry. Revise Covalent Bonding in Bonding & Structure for GCSE Chemistry with 25 exam-style questions and 21 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 13 of 13 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Knowledge Organiser: Covalent Bonding
Key Terms
- Covalent bond: shared pair of electrons between non-metals
- Molecule: fixed group of atoms joined by covalent bonds
- Single bond: 1 shared pair (—)
- Double bond: 2 shared pairs (=)
- Triple bond: 3 shared pairs (≡)
- Lone pair: non-bonding electron pair
Must-Know Facts
- Covalent bonding: non-metals SHARE electrons
- H needs 1 bond, O needs 2, N needs 3, C needs 4
- H₂ (single), O₂ (double), N₂ (triple)
- Strong bonds within molecules; weak forces between
- No brackets on dot-cross diagrams (no ions formed)
- Triple bond strongest and shortest
Key Equations
- H₂O: O forms 2 bonds (2 shared pairs with 2 H atoms)
- CO₂: C forms 2 double bonds with 2 O atoms (C=O=C)
- NH₃: N forms 3 bonds with 3 H atoms (plus 1 lone pair)
- CH₄: C forms 4 single bonds with 4 H atoms
Common Mistakes
- Confusing covalent and ionic bonding: Covalent = sharing between non-metals; ionic = transfer between metal and non-metal
- Drawing brackets on covalent dot-cross diagrams: No brackets needed — covalent bonding forms no ions
- Saying covalent compounds have high melting points: Simple molecular covalent compounds have LOW melting points — weak intermolecular forces (not bonds) break easily
- Mixing up lone pairs and bonding pairs: Only the shared (bonding) pairs count as the covalent bond — lone pairs stay on one atom
Practice questions for Covalent Bonding
Which of the following best describes a covalent bond?
Explain the difference between a bonding pair and a lone pair of electrons in a covalent molecule.
Quick recall flashcards
What is a covalent bond?
A shared pair of electrons between two non-metal atoms
What is a single covalent bond?
One shared pair of electrons between two atoms