Metals as conductors — AQA GCSE Chemistry
Test yourself on Metals as conductors with AQA GCSE practice questions.
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Metals as conductors explained
Metallic bonding produces a giant lattice of positive metal ions surrounded by delocalised electrons.
Read the full explanation
These delocalised electrons are not attached to any particular ion and are free to move throughout the structure. When a potential difference is applied across a metal, for example by connecting it to a battery in a circuit, the delocalised electrons drift towards the positive terminal. Because electrons carry negative charge, this movement of charge is an electric current. The more freely the electrons can move, the better the metal conducts. This explains why metals such as copper are used for electrical wiring, while materials without delocalised electrons, such as plastics, do not conduct. The same model also helps explain why metals conduct thermal energy.
Your focus
- Identify delocalised electrons as the mobile charge carriers in metals.
- Explain how the movement of delocalised electrons produces an electric current.
- Relate the presence of delocalised electrons to the good electrical conductivity of metals.
Metals as conductors exam tips
Marking Points
- Metals contain delocalised electrons that are free to move through the giant metallic lattice.
- The delocalised electrons carry electrical charge through the metal.
- When a potential difference is applied, the electrons move and constitute an electric current.
- The presence of mobile charge carriers explains why metals are good conductors of electricity.
- A named example, such as copper used in electrical wiring, can illustrate the property.
Examiner Tips
- 💡Name the charge carriers explicitly: delocalised electrons.
- 💡Explain that the electrons are free to move through the whole structure, not fixed to one ion.
- 💡Link the movement of electrons to the idea of charge being carried through the metal.
Common Mistakes
- Saying that the positive metal ions carry the current; in metallic conduction it is the delocalised electrons that move and carry charge.
- Stating that electrons are transferred from atom to atom as whole atoms move; the electrons are delocalised and move through the lattice.
- Confusing electrical conduction with thermal conduction; both involve delocalised electrons, but the statement here is specifically about carrying electrical charge.