Which statement best explains why alloys are generally harder than pure metals?
Alloys have a larger number of free delocalised electrons.
The different-sized atoms in an alloy distort the regular layers, preventing them from sliding over one another easily.
Strong covalent bonds form between the different types of metal atoms in the alloy.
The atoms in an alloy are held together by weak intermolecular forces.
48 exam-style questions on OCR GCSE Chemistry Properties of materials. Each one has a worked solution and a mark scheme showing where the marks go.