Structures and Bonding: Properties of Metals

Metals are arranged in a lattice structure with a sea of delocalised electrons surrounding the metallic cations. This is often referred to as the ‘metallic bond’.
Metallic bonds are strong due to the electrostatic attraction between the positive cations and the negatively charged delocalised electrons. This high strength of metallic bonds results in metals usually having high melting and boiling points.
Drawings of metal lattice structures should consist of positive metal ions fixed in position, surrounded by mobile or ‘delocalised’ electrons. It is these delocalised electrons that hold the structure together.
The delocalised electron model explains many key properties of metals. The constant movement of these electrons allows for excellent electrical conductivity, as they can carry an electric current.
Metals are also able to conduct heat effectively. This is due to the kinetic energy of the heat source being passed from one particle to the next via the vibrations of the delocalised electrons.
When force is applied to a metal, the layers of atoms can slide over each other, but the metallic bonding still holds the atoms together. This results in metals being malleable (able to be hammered or pressed permanently out of shape without breaking or cracking) and ductile (able to be drawn out into a thin wire).
The malleability and ductility of metals make them suitable for uses where they need to be shaped into a specific form, such as in crafting jewellery and in constructing buildings and vehicles.
Different types of metals can have varying properties due to differences in their atomic structures and bonding. For instance, some metals can be harder or softer, more or less reactive, or more or less dense. This makes different metals suitable for different applications, such as copper for electrical wires, due to it being an excellent conductor of electricity, and gold for jewellery, due to its resistance to tarnishing.
Alloys are mixtures of two or more metals (or a metal and a non-metal), which have been combined to improve the properties of the metal for a specific use. For example, steel is an alloy of iron and carbon which is used for its enhanced strength and resistance to rust.