Some sunscreens contain nanoparticles of titanium dioxide.
The table shows the sizes of some particles and objects.
| Particle or object | Diameter / nm |
|---|---|
| hydrogen atom | 0.1 |
| titanium dioxide particle in sunscreen | 20 |
| grain of fine sand | 100 000 |
| width of a human hair | 80 000 |
State the range of sizes of nanoparticles.
Give the name of the particle or object in the table that is a nanoparticle.
One nanometre (1 nm) is a very small length. Give 1 nm in metres.
Give two reasons why titanium dioxide nanoparticles are used in sunscreens.
Give one possible risk of using nanoparticles in sunscreens.
36 exam-style questions on Edexcel GCSE Chemistry 10.5 Bulk and surface properties of matter including nanoparticles, covering 10.5.1 Nanoparticles: size, uses and risks and 10.5.2 Comparing and selecting materials. Each one has a worked solution and a mark scheme showing where the marks go.