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MyGCSEScience · AQA Chemistry
Metallic Bonding — MyGCSEScience
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FreeScienceLessons · AQA ChemistryMetallic Bonding
Key facts
Metallic bonding
- Metals consist of a giant lattice of positive ions surrounded by a sea of delocalised electrons.
- Delocalised electrons = electrons that have left their parent atoms and are free to move throughout the metal.
- The metallic bond = electrostatic attraction between positive metal ions and delocalised electrons.
- Metals are elements, alloys are mixtures of metals.
Properties of metals explained
- Good conductors of electricity — delocalised electrons carry charge through the metal.
- Good conductors of heat — delocalised electrons transfer kinetic energy quickly.
- High melting points — strong metallic bonds require lots of energy to break.
- Malleable and ductile — layers of ions can slide past each other without breaking bonds (electrons readjust).
- Alloys are harder — different-sized atoms distort the regular lattice, making it harder for layers to slide.
Exam questions — 4 questions · 12 marks
⚡ Extended questions included. Read the hint. Show all working. AI marks against the real AQA mark scheme.
1 markMetallic conductionAQA 8462 P1 style
Why do metals conduct electricity?
A Metals contain free protons that carry electrical charge
B Metals have delocalised electrons that are free to move and carry electrical charge
C Metals form positive ions that can move through the structure
D Metals absorb electrons from the electrical supply and release them at the other end
3 marksWhy alloys are harderAQA 8462 P1 style
Pure copper is too soft for many uses. Explain why adding zinc to make brass makes the alloy harder than pure copper. (3 marks)
Hint: Pure metal: same-size atoms → layers slide. Alloy: different-size atoms → distort lattice → harder to slide → harder material.
+30 XP
1 markMetallic structureAQA 8462 P1 style
Which statement correctly describes the structure of a metal?
A A regular arrangement of positive ions held together by shared covalent bonds
B A giant lattice of positive metal ions surrounded by a sea of delocalised electrons
C A regular arrangement of neutral atoms held together by intermolecular forces
D Negative metal ions attracted to positive hydrogen ions in water
Module complete! 🎉
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