Two unknown compounds, P and Q, are tested.
| Compound | Melting point in ∘C^\circ\mathrm{C}∘C | Conducts electricity when solid | Conducts electricity when liquid |
|---|---|---|---|
| P | 920 | no | yes |
| Q | -42 | no | no |
Use the results to explain why compound P has a much higher melting point than compound Q.
122 exam-style questions on OCR GCSE Chemistry 2.3 Properties of materials, covering 2.3.1 Carbon bonding and the variety of organic compounds, 2.3.2 Diamond, graphite, fullerenes and graphene, 2.3.3 Bond strength, changes of state and predicting states, 2.3.4 Bulk properties and types of bonding, and 2.3.5 Nanoparticles: scale, surface area, uses and risks. Each one has a worked solution and a mark scheme showing where the marks go.