9.4 Reactivity Series

2026 Syllabus Objectives

  1. Core: State the order of the reactivity series as: potassium, sodium, calcium, magnesium, aluminium, carbon, zinc, iron, hydrogen, copper, silver, gold
  2. Core: Describe the reactions, if any, of:
    • (a) potassium, sodium and calcium with cold water
    • (b) magnesium with steam
    • (c) magnesium, zinc, iron, copper, silver and gold with dilute hydrochloric acid and explain these reactions in terms of the position of the metals in the reactivity series
  3. Core: Deduce an order of reactivity from a given set of experimental results
  4. Supplement: Describe the relative reactivities of metals in terms of their tendency to form positive ions, by displacement reactions, if any, with the aqueous ions of magnesium, zinc, iron, copper and silver
  5. Supplement: Explain the apparent unreactivity of aluminium in terms of its oxide layer

Understanding Metal Reactivity 🔬

Reactivity refers to the ease with which a chemical substance takes part in a chemical reaction. Different metals show varying levels of reactivity, and these differences can be observed through their reactions with water, acids, and other metal salt solutions.

The reactivity series of metals is an order of reactivity, giving the most reactive metal first, based on results from a range of experiments involving metals reacting with oxygen, water, dilute hydrochloric acid, and metal salt solutions.

Historical Context

Early civilisations used metals that could be found 'native' (such as gold) for decorative items and developed alloys such as bronze. Observable differences in the reactivity of different metals, such as the corrosion resistance of gold and silver compared to iron, suggested that there is a natural order of reactivity among metals.


The Reactivity Series 📊

The complete reactivity series arranges metals in order of decreasing reactivity:

PositionElementType
1 (Most reactive)Potassium (K\text{K})Metal
2Sodium (Na\text{Na})Metal
3Calcium (Ca\text{Ca})Metal
4Magnesium (Mg\text{Mg})Metal
5Aluminium (Al\text{Al})Metal
6Carbon (C\text{C})Non-metal
7Zinc (Zn\text{Zn})Metal
8Iron (Fe\text{Fe})Metal
9Hydrogen (H\text{H})Non-metal
10Copper (Cu\text{Cu})Metal
11Silver (Ag\text{Ag})Metal
12 (Least reactive)Gold (Au\text{Au})Metal

Key Point: Carbon and hydrogen are included in the reactivity series because they are used to extract metals from their oxides. Carbon is placed between aluminium and zinc because it can reduce zinc oxide to form zinc but cannot reduce aluminium oxide.

Memory Aid 🧠

"Please Send Cats, Monkeys And Cute Zebras Into Hot Countries Signed Gordon"

  • Please = Potassium
  • Send = Sodium
  • Cats = Calcium
  • Monkeys = Magnesium
  • And = Aluminium
  • Cute = Carbon
  • Zebras = Zinc
  • Into = Iron
  • Hot = Hydrogen
  • Countries = Copper
  • Signed = Silver
  • Gordon = Gold

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