Metallic Bonding

This lesson covers metallic bonding and the properties of metals, as required by the AQA GCSE Chemistry specification (4.2.3). Metallic bonding is the third and final type of bonding you need to understand. You must be able to describe the structure of metals, explain their properties in terms of metallic bonding, and explain why alloys are harder than pure metals.

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What Is Metallic Bonding?

Metallic bonding is the strong electrostatic force of attraction between positively charged metal ions and a sea of delocalised electrons.

In a metal:

1. Metal atoms are arranged in a regular pattern called a giant metallic lattice.
2. The outer shell electrons of each metal atom are delocalised — they are no longer associated with any particular atom and are free to move throughout the structure.
3. This leaves behind positively charged metal ions (cations) arranged in rows and layers.
4. The delocalised electrons form a "sea" of electrons that surrounds the metal ions.
5. The strong electrostatic attraction between the positive ions and the negative sea of electrons holds the structure together — this is the metallic bond.