Chemistry · May / June 2016 · Paper 12 · Question 22

The diagram shows the structure of brass. Why is brass harder than pure copper?

1. AThe zinc atoms form strong covalent bonds with the copper atoms.
2. BThe zinc atoms prevent layers of copper atoms from sliding over each other easily.
3. CThe zinc atoms prevent the ‘sea of electrons’ from moving freely in the solid.
4. DThe zinc atoms have more electrons than the copper atoms.

As printed in the paper