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IGCSE · Practice questions · Alloys and their properties

Mix for strength.

Six original Cambridge-style questions on alloys: what they are, examples, uses and the reason for their hardness.

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.
Keep these straight

Mixture, harder, disrupted layers.

01
Recall
[1 marks]

Define the term alloy.

  • A mixture of a metal with other elements (metals or non-metals). ✓
02
Recall
[2 marks]

Name the elements in (a) brass and (b) stainless steel.

  • (a) copper and zinc. ✓
  • (b) iron, with chromium, nickel and carbon. ✓
03
Recall
[2 marks]

Give one use of stainless steel and explain why it is suitable.

  • Cutlery (or sinks or surgical instruments). ✓
  • It is hard and resistant to rusting (corrosion). ✓
04
Explain
[3 marks]

(Extended) Explain, using ideas about particles, why brass is harder than pure copper.

  • In pure copper all the atoms are the same size and are arranged in regular layers that can slide over each other. ✓
  • In brass, zinc atoms of a different size distort the layers. ✓
  • The layers cannot slide as easily, so brass is harder. ✓
05
Explain
[2 marks]

Explain why an alloy is classified as a mixture and not a compound.

  • The elements in an alloy are not chemically combined. ✓
  • The composition can vary; there is no fixed ratio or formula. ✓
06
Analysis
[2 marks]

Pure iron is soft and rusts easily. Suggest two reasons why steel, not pure iron, is used for building bridges.

  • Steel is harder and stronger than pure iron. ✓
  • Some steels resist corrosion better (and steel can be protected more effectively). ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.