Chapter summary
Chemical Bonding, at a glance
Explain particles, molecular shape and material properties through electrostatic attraction.
A-Level 8873, revised syllabus (2026-2027)
Quick revision
Revisit the essentials, then return to an explanation when you need it.
- Particles
Atoms, molecules, ions or ions with delocalised electrons?
- Attraction
Which electrostatic attraction holds the structure?
- Change
Which attraction is overcome, or which charge carrier moves?
- Conclusion
Link that mechanism directly to the measured property.
| Pair of ideas | Difference |
|---|---|
| Bond polarity / molecular polarity | Polar bonds may cancel through symmetry. |
| Sigma / pi | Head-on axial overlap / sideways p overlap. |
| Melting iodine / breaking I2 | Intermolecular separation / covalent bond breaking. |
| NH3 / NH4+ | Three bonds plus lone pair / four bonds, no lone pair. |
| Diamond / graphite | 3-D four-coordinate network / three-coordinate sheets with delocalised electrons. |