Nanoparticles of titanium dioxide are added to some paints. In sunlight the nanoparticles break down dirt on the painted surface.
Which property of the nanoparticles makes them effective at breaking down the dirt?
Their large surface area in contact with the dirt
Their low density compared with that of the paint
Their small mass compared with that of the paint
Their high melting point compared with the dirt
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.