A manufacturer prepares two batches of cubic particles of the same metal for use as a catalyst. In each particle, the atoms are arranged in a cubic array. For counting purposes, only atoms in the outermost cubic layer are exposed to the surroundings.
| Batch | Number of atoms along each edge | Total number of atoms |
|---|---|---|
| A | 7 | 343 |
| B | 10 | 1000 |
Calculate the percentage of atoms that are surface atoms in each batch.
Give your answers to one decimal place.
The manufacturer wants to use the least possible mass of metal to produce the same catalytic effect.
Explain which batch should be selected.
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.