Metallic Lattice Structures
- Metals form giant metallic lattices in which the metal ions are surrounded by a ‘sea’ of delocalised electrons
- The metal ions are often packed in hexagonal layers or in a cubic arrangement
- This layered structure with the delocalised electrons gives a metal its key properties
Layers of copper ions (the delocalised electrons are not shown in the diagram)
- If other atoms are added to the metal structure, such as carbon atoms, this creates an alloy
- Alloys are much stronger than pure metals, because the other atoms stop the layers of metal ions sliding over each other easily
- The strength of the metallic attraction can be increased by:
- Increasing the number of delocalised electrons per metal atom
- Increasing the positive charges on the metal centres in the lattice
- Decreasing the size of the metal ions
- Due to the delocalised ‘sea’ of electrons, metallic structures have some characteristic properties shown below:
Metallic Bonding Properties Table
Exam Tip
You should be able to draw the structure of a metal with positive ions in layers and the delocalised electrons surrounding the ions
If drawing the structure of a metal in the exam, make sure to include labels for metal ions and delocalised electrons