An electrical component needs a support block. The block must:
The block may sometimes be struck by tools during maintenance.
Four samples are tested.
| Sample | Result of scratch test | Result when bent | Does an electric current flow? | Maximum compressive stress before failure in MPa\text{MPa}MPa |
|---|---|---|---|---|
| P | scratched easily | bends | no | 55 |
| Q | not scratched easily | snaps | no | 90 |
| R | not scratched easily | bends | yes | 220 |
| S | scratched easily | bends | no | 20 |
Which sample is most likely to be a clay ceramic?
Explain why the sample you identified meets both requirements for the support. Suggest one risk of using this sample.
136 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.