A nanoparticle is a cube made of 64 atoms, with 4 atoms along each edge.
Atoms on the outside faces of the cube are surface atoms. All the other atoms are inside the cube.
What percentage of the atoms in the nanoparticle are surface atoms?
12.5%
37.5%
50%
87.5%
60 exam-style questions on OCR GCSE Chemistry 2.3 Properties of materials, covering 2.3.1 Carbon bonding and the variety of organic compounds, 2.3.2 Diamond, graphite, fullerenes and graphene, 2.3.3 Bond strength, changes of state and predicting states, 2.3.4 Bulk properties and types of bonding, and 2.3.5 Nanoparticles: scale, surface area, uses and risks. Each one has a worked solution and a mark scheme showing where the marks go.