Properties and uses of some metals
4 marks · NormalThe table shows the melting point and main use of some metals.
| Metal | Melting point (°C) | Main use |
|---|---|---|
| Aluminium | 660 | Overhead electricity cables |
| Copper | 1085 | Electrical wiring |
| Iron | 1538 | Building structures |
Which metal from the table is most suitable for overhead power cables? Give one reason for your choice.
Explain why copper is commonly used for making electrical wiring.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Aluminium. Reason: It is used for overhead cables due to its low density and ability to conduct electricity.
(b) Copper is a good conductor of electricity, making it ideal for wiring. · must show good conductor, can be drawn into wires
Also accept: Aluminium - low density makes it suitable for cables; Copper - very good conductor, ductile, or resists corrosion
Common mistakes: Iron is used for cables; Main reason is cost (not a property assessed in data provided)
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Identifies aluminium as most suitable for overhead power cables.
B2 (a) · 1 mark · Gives a correct reason (low density or good conductor of electricity).
B3 (b) · 1 mark · States copper is a good conductor of electricity.
B4 (b) · 1 mark · Any other relevant reason: e.g., copper can be drawn into wires (ductile) OR it resists corrosion.
Worked solution
a) Aluminium. It is suitable because it is lightweight (low density) and a good conductor of electricity, making it ideal for overhead power cables.
b) Copper is commonly used for electrical wiring because it is a very good conductor of electricity and can be drawn into thin wires.