A manufacturer makes plastic housings for handheld scanners that are shared by many workers. An additive is mixed into the plastic to reduce bacterial growth on the housings.
At the masses shown, both additives reduce bacterial growth equally well. Workers may breathe in some additive while mixing it into the plastic.
Each housing contains 0.25 kg of plastic. A batch contains 800 housings.
| Additive | Cost in £ for each kg | Mass needed for each kg of plastic in g | Evidence about possible health risk during mixing |
|---|---|---|---|
| Nanoparticles | 1500 | 0.060 | long-term effects if breathed in are not known |
| Fine particles | 30 | 4.0 | tests at this amount show a low health risk |
Calculate the total cost of each additive needed to make this batch of housings.
The manufacturer chooses the fine-particle additive.
Explain why this is a reasonable decision.
104 exam-style questions on AQA GCSE Chemistry 2.4 Bulk and surface properties of matter including nanoparticles, covering 2.4.1 Sizes of particles and their properties and 2.4.2 Uses of nanoparticles. Each one has a worked solution and a mark scheme showing where the marks go.