Two covalent substances, X and Y, have the melting points shown.
| Substance | Melting point in ∘C^\circ\mathrm{C}∘C |
|---|---|
| X | -90 |
| Y | 1650 |
Using the data, explain which substance is simple molecular and which has a giant covalent structure. Then explain what is overcome when each substance melts.
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.