Metallic Bonding

This lesson covers metallic bonding as required by the AQA GCSE Combined Science Trilogy specification (8464), section 4.2.3. You need to understand the structure of metals, the nature of the metallic bond, and how this structure explains the properties of metals.

---

What Is Metallic Bonding?

Metallic bonding is the strong electrostatic force of attraction between positive metal ions (cations) and a "sea" of delocalised electrons.

In a metal:

1. Metal atoms lose their outer shell electrons, forming positive ions.
2. The lost electrons become delocalised — they are no longer associated with any particular atom and are free to move throughout the entire structure.
3. The positive metal ions are arranged in a regular lattice (a repeating pattern).
4. The delocalised electrons move freely between the ions, forming a "sea of electrons."
5. The strong electrostatic attraction between the positive ions and the sea of negative electrons holds the structure together.

$\text{Metal atoms} \rightarrow \text{Positive metal ions (M}^{n+}\text{)} + \text{Delocalised electrons (e}^-\text{)}$Metal atoms→Positive metal ions (Mn+)+Delocalised electrons (e−)