Metallic Bonding
Build confidence in Metallic Bonding for GCSE Chemistry with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Metallic bonding is a lattice of positive ions in a sea of delocalised electrons, which explains conductivity and malleability.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Metallic bonding occurs in metals and alloys. The metal atoms are arranged in a giant structure, and the electrons in their outer shells are delocalised.
Delocalised means the electrons are no longer associated with any particular atom and are free to move throughout the whole structure. The bonding is the strong electrostatic attraction between the positive metal ions and these delocalised electrons.
This structure explains the properties directly. Delocalised electrons carry charge and energy, so metals conduct electricity and heat well. The layers of ions can slide over each other, so metals are malleable. And the strong attraction throughout gives high melting and boiling points.
Revision notes
The structure
Metal atoms are arranged in a giant structure of layers.
The electrons in the outer shell of each atom are delocalised — free to move throughout the whole structure. The metal atoms therefore exist as positive ions.
The bond itself
Metallic bonding is the strong electrostatic attraction between the positive metal ions and the delocalised electrons.
This attraction acts throughout the entire structure, which is why a great deal of energy is needed to break it.
Explaining the properties
Conductivity: delocalised electrons are free to move and carry electrical charge and thermal energy through the metal.
Malleability: the layers of ions can slide over each other, so the metal can be bent or hammered into shape. High melting point: the electrostatic attraction throughout the structure is strong.
Key points
- Metallic bonding occurs in metals and alloys.
- Outer shell electrons are delocalised.
- Delocalised electrons move throughout the structure.
- The bond is attraction between positive ions and these electrons.
- Delocalised electrons allow conduction of heat and electricity.
- Layers of ions sliding explains malleability.
Worked examples
Example 1
Explain what is meant by metallic bonding. [2 marks]
Model answer
Metallic bonding is the strong electrostatic attraction between the positive metal ions and the delocalised electrons (1 mark), which are free to move throughout the whole giant structure (1 mark).
Example 2
Explain why metals conduct electricity. [2 marks]
Model answer
Metals contain delocalised electrons that are free to move throughout the structure (1 mark), and these moving electrons carry electrical charge through the metal (1 mark).
Example 3
Explain why metals can be bent and shaped. [2 marks]
Model answer
The metal ions are arranged in layers (1 mark) which can slide over each other without breaking the metallic bonding (1 mark).
Common mistakes
Saying metals conduct because ions move.
It is the delocalised electrons that move and carry the charge.
Forgetting the word delocalised.
It is the key term and usually carries a mark.
Saying the layers break when a metal is bent.
They slide over each other; the bonding is maintained.
Describing metal atoms rather than ions.
Once the outer electrons are delocalised, the atoms are positive ions.
Exam tips
- Always use the word delocalised.
- Explain conductivity through moving electrons carrying charge.
- Explain malleability through sliding layers.
- Say positive ions rather than atoms in a metallic structure.
Key terms
- Metallic bonding
- Attraction between positive metal ions and delocalised electrons.
- Delocalised electron
- An electron free to move throughout a structure.
- Malleable
- Able to be hammered or bent into shape.
- Giant structure
- A structure containing very many atoms bonded throughout.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.