Metals vs Non-Metals

Elements in nature are broadly classified as either metallic or non-metallic, based on their chemical and physical properties.

Metals

Generally, metals are good conductors of electricity and heat. They typically have a shiny appearance and are malleable, which means they can be moulded into various shapes without breaking.

Let’s look at some of the reasons for these properties:

• Conductivity: Metals are excellent conductors due to their delocalised electrons, which can freely carry charge and energy.

• High Melting and Boiling Points: The strong electrostatic forces of attraction between the positively charged ions and the sea of delocalised electrons in metals require a significant amount of energy to overcome.

• Ductility and Malleability: Metal ions can slide over each other while remaining bonded by the delocalised electrons, allowing metals to be formed into sheets (malleability) or drawn into wires (ductility).

Non-metals

In contrast, non-metals are elements that are generally poor conductors of electricity and heat. They are often brittle in their solid state. Here’s why they have such properties:

• Conductivity: Non-metals are poor conductors of electricity and heat because their atomic or molecular structure does not allow electrons to flow freely.

• Low Melting and Boiling Points: The forces of attraction between non-metal atoms or molecules are relatively weak, so less energy is required to separate them.

• Brittleness: Non-metals are usually brittle in their solid state. This is because, unlike metals, their atoms or molecules are held together by covalent or intermolecular forces rather than metallic bonds. Therefore, their atomic or molecular structures are more likely to break under stress than deform.

Summary of Properties

In summary, the properties of metallic and non-metallic elements are:

Property	Metals	Non-metals
Conductivity of electricity and heat	High	Low
Ductility and malleability	High	Low (brittle)
Melting and boiling points	Generally high	Generally low

However, there are notable exceptions to these general rules:

• Metals like mercury and gallium have low melting points and are liquid at room temperature.

• Non-metal giant covalent structures, such as diamond, have very high melting points.

• Graphite, a form of carbon (non-metal), conducts electricity due to the delocalised electrons within its layers.