A company wants to add a substance to a paint so that the paint kills bacteria on a painted wall. The table gives information about two substances the company could use.
Table: The cost, the mass needed for each litre of paint, and the possible risk to health of two substances that kill bacteria
| Substance | Cost in £ for each kg | Mass needed for each litre of paint in g | Possible risk to health |
|---|---|---|---|
| Nanoparticles of silver | 900 | 0.40 | not fully known |
| Fine particles of copper | 12 | 30 | low |
Calculate the cost of the substance needed for one litre of paint, for each of the two substances.
The company decides to use the fine particles of copper.
Use the table to explain this decision.
40 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.