Why are metals malleable and ductile?

Metals are malleable and ductile due to the unique structure of their atoms, which allows layers to slide over each other.

Metals are made up of a lattice of positive ions surrounded by a 'sea' of delocalised electrons. This structure is often referred to as a 'metallic bond'. The positive metal ions are arranged in a regular pattern, but the electrons are free to move throughout the structure. This movement of electrons is what gives metals their good electrical and thermal conductivity.

The malleability and ductility of metals, which means their ability to be shaped or drawn into wires, is also a result of this unique structure. When a force is applied to a metal, the layers of positive ions can slide over each other. This is possible because the delocalised electrons can adjust their positions and maintain the attraction between the positive ions and the 'sea' of electrons. This allows the metal to change shape without breaking or cracking.

To understand more about how metallic bonds contribute to these properties, visit Properties of Metals.

The structure and arrangement of these ions can be better understood by exploring the concept of lattice structures in metals.

In contrast, in a covalent or ionic structure, the atoms or ions are held in a rigid structure and cannot easily move past each other. If a force is applied, the structure is more likely to break or shatter, rather than bend or stretch. This is why covalent and ionic substances are generally brittle, not malleable or ductile.

Different metals have varying degrees of malleability and ductility, depending on the strength of their metallic bonds. For example, gold is very malleable and can be hammered into extremely thin sheets, while iron is less malleable but very ductile, making it ideal for drawing into wires. This variation in properties is due to differences in the number of delocalised electrons and the size and charge of the metal ions. For further details on how these properties vary in transition metals, click here.

IB Chemistry Tutor Summary: Metals are malleable and ductile because of their structure, where positive ions are in a lattice with free-moving electrons around them. This lets metal ions slide without breaking, unlike the rigid bonds in other materials. Variations in these properties among metals depend on their metallic bond strength, influenced by the electron count and ion size and charge.