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K223 / K225 / 2027
Periodicity and Metals

Lesson 7 of 8

Use reactivity to explain extraction and heating

Strongly bound compounds of reactive metals are harder to break down.

SEC G2 Science K223 / K225 (2027)

  • I can relate extraction to reactivity.Syllabus

    Syllabus K223 / K225, 7.3(c). Relate extraction to reactivity

Use reactivity to explain extraction and heating

Strongly bound compounds of reactive metals are harder to break down.

An ore contains a metal compound in a form worth extracting. More reactive metals generally need more demanding extraction. Carbon can reduce oxides of metals below it in the relevant series, such as zinc, iron, lead and copper, when heated appropriately. Very reactive metals such as potassium, sodium, calcium and magnesium require other methods, commonly electrolysis of suitable molten compounds. This is a principle, not a requirement to memorise every industrial furnace.

Check your understanding

Why is heating magnesium oxide with carbon not the usual way to extract magnesium?

  1. Magnesium is more reactive than carbon, so carbon cannot remove its oxygen.
  2. Magnesium is less reactive than carbon, so it would bond to the carbon instead.
  3. Carbon would react with the magnesium oxide too violently for the furnace.
Show the answer

Magnesium is more reactive than carbon, so carbon cannot remove its oxygen.

Carbon reduces oxides of metals below it in the reactivity series, such as iron and zinc. Magnesium is above carbon, so it is extracted by electrolysis of a molten compound.