How does the extraction of reactive metals differ from less reactive ones?

Reactive metals are extracted using electrolysis, while less reactive ones are extracted by reduction with carbon or carbon monoxide.

Reactive metals, such as aluminium and sodium, are found in the Earth's crust as compounds. These metals are so reactive that they cannot be extracted by reduction with carbon or carbon monoxide, which are the methods typically used for less reactive metals. Instead, they are extracted using a process called electrolysis. Electrolysis involves passing an electric current through a compound to cause it to break down into its constituent elements. For example, aluminium is extracted from its ore, bauxite, by first converting it into aluminium oxide and then using electrolysis to separate the aluminium from the oxygen.

Less reactive metals, on the other hand, can be extracted by reduction with carbon or carbon monoxide. This is because these metals are not as strongly bonded to their non-metal parts as the more reactive metals are. For instance, iron, a less reactive metal, is extracted from its ore, haematite, by reduction with carbon in a blast furnace. The carbon or carbon monoxide removes the oxygen from the iron ore, leaving behind the pure iron.

The method of extraction used depends on the reactivity of the metal. The more reactive the metal, the more energy is required to extract it from its ore. This is why electrolysis, which requires a lot of energy, is used for the extraction of reactive metals. Less reactive metals, which require less energy to extract, can be obtained through reduction with carbon or carbon monoxide. This difference in extraction methods is a key aspect of the reactivity series of metals, a fundamental concept in IGCSE Chemistry.