Metallic Bonding and Properties of Metals
Quick Notes:
- A metallic bond is the electrostatic attraction between a lattice of positive metal cations and a sea of delocalized electrons.
- This structure gives rise to characteristic metal properties:
- Electrical conductivity: delocalized electrons move freely and carry charge.
- Thermal conductivity: energy is transferred by the movement of electrons and vibrations in the lattice.
- Malleability: metal layers can slide over one another without breaking bonds.
- Metals are shiny, conductive, and flexible, making them useful in tools, wires, and structural materials.
Full Notes:
What Is a Metallic Bond?
Metallic bonding is the strong electrostatic attraction between positive metal ions (cations) and a sea of delocalised electrons.
Metal atoms form positive ions (cations) easily because their outer electrons are weakly attracted to the nucleus. These electrons can drift away, becoming delocalised and forming a ‘sea’ of negative charge. The resulting positive metal ions are strongly attracted to this sea of delocalised electrons. This electrostatic attraction holds the structure together in a rigid, fixed arrangement.
Example Structure of Sodium (Na)
Each sodium atom loses one outer electron*, forming Na+ ions.
The lost electrons become delocalised, forming an electron cloud.

There is strong attraction between Na+ ions and the delocalised electrons, which holds the metal together.

Explaining the Properties of Metals
Metallic bonding helps explain unique physical properties of metals.
Electrical Conductivity
- Delocalized electrons are mobile charge carriers.
- When a voltage is applied, they flow, allowing electrical current to pass.
- Metals conduct electricity in both solid and liquid states.
Thermal Conductivity
- Free-moving electrons transfer kinetic energy rapidly through the metal.
- Vibrations of metal ions also pass energy along the lattice.
- This makes metals good at conducting heat.
Malleability and Ductility
- Malleability = can be hammered or rolled into sheets.
- Ductility = can be drawn into wires.
- Metal atoms are arranged in layers that can slide over each other.
- Because the electrons are not bound to specific atoms, the structure stays intact during deformation.
Summary of Properties and Bonding
Property | How Metallic Bonding Explains It | Outcome / Use |
---|---|---|
Electrical conductivity | Delocalized electrons move freely and carry charge through the lattice. | Good for wires and electrodes. |
Thermal conductivity | Electrons and lattice vibrations transfer energy efficiently. | Useful in heating elements and heat sinks. |
Malleability | Layers of ions can slide without breaking the attraction to the electron sea. | Can be rolled into sheets for tools and structural parts. |
Ductility | Non-directional bonding allows stretching into wires without fracture. | Drawn into long, thin wires for circuits. |
Shiny appearance | Surface electrons respond collectively to light (free-electron surface). | Characteristic metallic lustre. |
Application in Experimental Tools
Metals are used in wires, electrodes, beakers, and support stands due to:
- Electrical conductivity (for circuits and probes)
- Thermal conductivity (for heating elements)
- Durability and malleability (to form complex lab shapes)
Their bonding and structure make them ideal for frequent handling, high temperatures, and mechanical use in laboratory environments.
Summary
- Metallic bonding is the electrostatic attraction between positive metal ions and delocalized electrons.
- Free electrons explain electrical and thermal conductivity.
- Layered structures and non-directional bonding explain malleability and ductility.
- These properties make metals suitable for wires, electrodes, heating parts, and robust lab equipment.