In metals, atoms give up some of their electrons to form a “sea” of delocalised electrons that move freely throughout the solid. The remaining positively charged metal ions are arranged in a regular, repeating pattern called a giant lattice. The attraction between this lattice of positive ions and the sea of electrons holds the metal together. This is what we call metallic bonding.
Imagine a crowded dance floor (the metal lattice) where dancers (positive ions) are standing still. The music (delocalised electrons) flows freely around them, keeping everyone together and allowing the dancers to move smoothly without bumping into each other. The music’s energy keeps the whole group together, just like the electron sea holds the metal lattice together.
The freely moving electrons can carry electric charge easily. When a voltage is applied, the electrons drift through the lattice, creating an electric current. Similarly, heat energy can be transferred quickly by the same electrons, which is why metals feel hot to the touch.
| Metal | Crystal Lattice | Typical Property |
|---|---|---|
| Iron (Fe) | Body‑centered cubic (BCC) | Strong, good conductor |
| Copper (Cu) | Face‑centered cubic (FCC) | Excellent conductor, malleable |
| Aluminium (Al) | Face‑centered cubic (FCC) | Lightweight, good conductor |
What is the main reason metals conduct electricity?
A) They have many covalent bonds.
B) They have a sea of delocalised electrons.
C) They are insulators.
Answer: B – the free electrons move through the lattice.
Metallic bonding is the electrostatic attraction between a giant lattice of positive metal ions and a sea of delocalised electrons. This bond gives metals their unique combination of strength, conductivity, and shiny appearance.