Industrial components are often manufactured from alloys or treated with specific coatings to enhance their mechanical properties and prevent degradation. Which of the following statements correctly explains the chemical or structural principle behind these materials?
Brass is harder than pure copper because the different-sized zinc atoms distort the regular layers of copper atoms, preventing them from sliding over one another easily.
Galvanising a steel component with zinc only prevents rust as long as the coating remains completely unbroken to act as a physical barrier to oxygen and water.
Transition metals such as iron and nickel have low densities and low melting points, which allows them to be easily cast into intricate industrial shapes.
Sacrificial protection of an iron pipe using a block of copper works because copper is more reactive than iron and will oxidise in its place.
97 exam-style questions on Edexcel GCSE Chemistry 6.1 Transition metals, alloys and corrosion, covering 6.1.1 Properties of transition metals, 6.1.2 Corrosion and its prevention, and 6.1.3 Alloys and the uses of metals. Each one has a worked solution and a mark scheme showing where the marks go.