1. 1
   A piece of pure copper metal consists of copper atoms arranged in a regular, repeating pattern that extends throughout the entire piece of metal.

   (a)

   What term describes this type of structure?

   [1 mark]

   • AA collection of separate, individual copper molecules
   • BA giant structure of atoms arranged in a regular pattern
   • CA simple covalent structure of shared electron pairs
   • DA random, unordered arrangement of atoms

   (b)

   In metallic bonding, what happens to the electrons in the highest occupied energy level (outer shell) of the metal atoms?

   [1 mark]

   • AThey remain fixed in place around one single atom
   • BThey are transferred completely to a neighbouring non-metal atom
   • CThey become delocalised and are free to move throughout the whole structure
   • DThey are shared between only two neighbouring atoms

   (c)

   Explain what is meant by the term 'delocalised' when describing the electrons in this piece of copper metal.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A piece of aluminium metal is described as a lattice of positive metal ions surrounded by a 'sea' of delocalised electrons that are free to move throughout the whole structure.

   (a)

   In a piece of aluminium metal, positive ions are arranged in a regular lattice surrounded by a 'sea' of delocalised electrons. What is the overall charge of the ions in this metallic lattice?

   [1 mark]

   • AIt varies randomly between ions
   • BNegative
   • CNo overall charge
   • DPositive

   (b)

   What holds the positive metal ions together in this lattice of aluminium?

   [1 mark]

   • AShared pairs of electrons between neighbouring positive ions
   • BStrong electrostatic attraction between the positive ions and the delocalised electrons
   • CWeak forces between separate aluminium molecules
   • DAttraction between the positive ions themselves, with no involvement of electrons

   (c)

   Explain why the aluminium atoms in this structure become positively charged ions.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A block of pure iron is another example of a metallic structure, consisting of iron ions arranged in a regular lattice surrounded by delocalised electrons.

   (a)

   Describe the structure of iron in terms of the arrangement of its ions and its delocalised electrons.

   [3 marks]

   (b)

   Explain in detail how the strong electrostatic attraction between the positive iron ions and the delocalised electrons holds the whole metallic structure together.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A student compares the metallic bonding found in a block of magnesium metal with the ionic bonding and covalent bonding studied previously, to understand what makes metallic bonding distinctive.

   (a)

   Describe metallic bonding in detail, including the arrangement of ions, the behaviour of delocalised electrons, and the forces that hold a metallic structure together.

   [6 marks]

   (b)

   Explain why the metallic bonding model, involving a lattice of positive ions and delocalised electrons, is different from the ionic bonding and covalent bonding models, in terms of how the electrons behave.

   [6 marks]

   Total for question 4: 12 marks

End of questions