Metallic Bonding
- Metal elements form giant metallic lattice structures
- Outer shell of electrons of each metal atom is delocalized
- Metal atoms become positive metal ions
- Positive metal ions attracted to delocalised electrons
- Closely packed metal ions among ‘sea’ of delocalised electrons
| Property of metals | Explanation |
| High melting/boiling points | Giant structure, strong attraction between ions and electrons- the more delocalised electrons per atom, higher mpt/bpt. |
| Good electricity and heat conductors | Delocalised electrons conduct electricity and can pass kinetic energy to each other |
| Malleable and ductile | No bonds holding ions together and ions can slide over each other, new shape is retained. |
| Strong | Electrostatic attractions between ions and electrons. Bigger charge and smaller ions increase strength. |
| Insoluble (except in liquid metals) | Strength of metallic bonds |
Metallic bond strength:
- Increases across a period as more electrons become delocalized
- Decreases down a group as the atomic radius increases
Magnesium is an example of a metallic crystal with the above properties. Each magnesium atom loses their 2 outer electrons to become Mg2+ ions.