Researchers are investigating two forms of substance X for use in medical imaging. Earlier studies found that the bulk form was safe to use in people.
Equal samples of one type of cell were each exposed to 10 mg of substance X. The percentage of cells showing damage was measured after 12 hours and after 48 hours.
| Form of substance X | Mean particle diameter in nm | Cells showing damage after 12 hours in % | Cells showing damage after 48 hours in % |
|---|---|---|---|
| Bulk particles | 25 000 | 1 | 1 |
| Nanoparticles | 25 | 3 | 12 |
Explain why the earlier evidence about the bulk form is not enough to conclude that the nanoparticles are safe. Use the data in the table.
Suggest one further investigation that should be carried out before the nanoparticles are used in people.
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.