The Properties of Metals, Ionic Compounds, Covalent Substances

Properties of Metals:

Metals are solid at room temperature, with the exception of mercury.
They have high melting and boiling points due to the strength of the metallic bonding.
They are malleable and ductile, meaning they can be bent and stretched without breaking.
Metals conduct heat and electricity well. This is due to their ‘sea’ of delocalised electrons which can move and transfer energy.
Most metals are lustrous, exhibiting a shiny appearance.
They are usually dense and heavy.

Properties of Ionic Compounds:

Ionic compounds, such as table salt (sodium chloride), are generally solid and crystalline at room temperature.
They have high melting and boiling points due to strong ionic bonds.
When dissolved in water or melted, ionic compounds can conduct electricity as the ions are free to move.
Ionic compounds are brittle and can shatter when an amount of force is applied. This is due to the arrangement of ions in their crystal lattice structure.

Properties of Covalent Substances:

Covalent substances can be broken down into two types: simple molecular substances and giant covalent structures.
Simple molecular substances, like water or oxygen, have low melting and boiling points as they are held together by weak intermolecular forces.
These substances do not conduct electricity as there are no mobile electrons or ions.
Giant covalent structures, like diamond or silicon dioxide, have high melting and boiling points as they are held together by many strong covalent bonds.
With the exception of graphite and some forms of silicon, giant covalent structures do not conduct electricity.
Graphite, a form of carbon, is unique among covalent materials because it conducts electricity and is slippery. This is due to each carbon atom only making three covalent bonds creating layers that can slide over each other, and one electron from each carbon atom is delocalised, allowing electrical conductivity.