AQA GCSE Chemistry (8462), Higher tier · Bonding, structure and the properties of matter › Bonding, structure and properties
Practise Metals as conductors. 12 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Metals are good conductors of electricity.
(a) Why are metals good conductors of electricity? Tick (✓) one box.[1]
Delocalised electrons carry charge through the metal.
Ions move through the metal.
Metal atoms are shiny.
Metals have high melting points.
(b) Give one use of copper that depends on it being a good conductor of electricity.[1]
(c) Which of these substances does not conduct electricity when it is solid? Tick (✓) one box.[1]
Aluminium
Copper
Graphite
Sodium chloride
(d) A saucepan is made of steel and has a plastic handle. Suggest why.[2]
Show the answer and mark scheme
(a)Answer: Delocalised electrons carry charge through the metal.
(b)Answer: electrical wires / cables
electrical wires / cables / circuit connections
(c)Answer: Sodium chloride
(d)Answer: Steel conducts thermal energy well, so it heats the food; plastic is a poor conductor, so the handle stays cool enough to hold.
steel is a good (thermal) conductor so it transfers energy to the food
plastic is a poor conductor / insulator so the handle stays cool (safe to hold)
Question 2Medium6 marks
Copper is used for electrical wiring and for the bases of some saucepans.
(a) Explain why solid copper conducts electricity but solid copper(II) chloride does not.[3]
(b) Explain how thermal energy is transferred through a metal.[2]
(c) Aluminium is used for overhead power cables, even though copper is a better conductor. Suggest one reason why.[1]
Show the answer and mark scheme
(a)Answer: Copper has delocalised electrons that move through the structure carrying charge; in solid copper(II) chloride the ions are fixed and there are no delocalised electrons.
copper has delocalised electrons
which move through the structure and carry (electrical) charge
in solid copper(II) chloride the ions are in fixed positions / cannot move (and there are no delocalised electrons)
(b)Answer: Delocalised electrons gain kinetic energy and move through the metal, transferring energy to other particles.
delocalised electrons gain (kinetic) energy
they move through the metal and transfer the energy (to other particles)
(c)Answer: Aluminium has a lower density, so the cables are lighter.
aluminium has a lower density / is lighter / is cheaper
Question 3Hard5 marks
An engineer needs to choose a metal for a heat sink, a part that must conduct thermal energy away from a hot electronic component as quickly as possible.
(a) Describe an experiment the engineer could do to compare how well rods of different metals conduct thermal energy.[3]
(b) Explain how thermal energy is transferred through a metal.[2]
Show the answer and mark scheme
(a)Answer: Use rods of the same size of each metal, with a pin attached near one end of each rod using a small amount of wax; heat the other ends in the same way at the same time and time how long it takes for each pin to fall. The shortest time shows the best conductor.
use rods of the same length and diameter, each with a pin attached near one end using a small blob of wax
heat the other end of each rod in the same way (e.g. in the same hot water bath, at the same time)
time how long it takes for each pin to fall: the shortest time shows the best thermal conductor
(b)Answer: The delocalised electrons gain energy at the hot end, move through the metal and transfer the energy to other particles further along.
the delocalised electrons gain (kinetic) energy where the metal is hot
the delocalised electrons move through the metal and transfer the energy to other parts / particles