The reactivity series — AQA GCSE Chemistry
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The reactivity series explained
The reactivity series covers 7 specification points, including When metals react with other substances the… and The reactivity of a metal is related to its….
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Open a point below for its explanation and revision guidance.
When metals react with other substances the metal atoms form positive ions.
This statement explains what happens to metal atoms during chemical reactions. Metal atoms lose one or more outer-shell electrons and become positively charged ions. For example, a sodium atom loses one electron to form Na⁺, a magnesium atom loses two electrons to form Mg²⁺, and an aluminium atom loses three electrons to form Al³⁺. The number of positive charges equals the number of electrons lost, which matches the group number for many metals. This ion formation is the key behaviour that underlies the reactivity series: the more readily a metal loses electrons, the more reactive it is. You should be able to write the ion formed by a named metal, relate the charge to electrons lost, and explain that the positive ion is produced because protons outnumber electrons after loss. This idea supports later work on displacement, electrolysis and ionic bonding.
The reactivity of a metal is related to its tendency to form positive ions.
This statement links a metal's position in the reactivity series to how easily its atoms lose electrons and become positive ions. A reactive metal, such as potassium or calcium, loses its outer electrons readily and therefore forms positive ions easily. A less reactive metal, such as copper or gold, holds its electrons more strongly and forms positive ions only with difficulty. The greater the tendency to form positive ions, the more vigorously the metal reacts with water, acid or oxygen, and the more readily it displaces a less reactive metal from its compound. For example, zinc displaces copper from copper sulfate solution because zinc forms positive ions more readily than copper does. You should be able to use this idea to predict and explain trends in reactivity, rather than simply recalling a list.
Metals can be arranged in order of their reactivity in a reactivity series.
This statement requires you to know that metals can be placed in order of reactivity, from the most reactive to the least reactive. A common order, starting with the most reactive, is potassium, sodium, calcium, magnesium, aluminium, zinc, iron, copper, silver and gold. The series is supported by evidence: reactions with water or dilute acid, and displacement reactions, show which metals are more reactive. For example, potassium reacts vigorously with cold water while iron reacts only slowly with steam, and zinc displaces copper from copper sulfate solution. You should be able to recall or use the order, place a given metal correctly, and use the series to predict whether a displacement reaction occurs. The series is a model based on experimental evidence, not a random list, and it links directly to how readily each metal forms positive ions.
The metals potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper can be put in order of their reactivity from their reactions with water and dilute acids.
Reactivity is judged by how vigorously a metal reacts with water or dilute acid. Potassium, sodium and lithium react with cold water, giving metal hydroxide and hydrogen; potassium is most vigorous, sodium fizzes and may melt, lithium fizzes steadily. Calcium reacts steadily with water, producing a slightly soluble hydroxide. Magnesium reacts very slowly with cold water but rapidly with dilute acid; zinc and iron react only with acid, iron more slowly; copper reacts with neither water nor dilute acid. The observed order is K > Na > Li > Ca > Mg > Zn > Fe > Cu. Reactivity reflects the tendency to form a positive ion, so the most reactive metals lose electrons most readily.
The non-metals hydrogen and carbon are often included in the reactivity series.
The reactivity series is not limited to metals. Hydrogen and carbon are non-metals placed among the metals to predict displacement and extraction. Hydrogen sits between lead and copper in the usual order, so metals above hydrogen displace it from dilute acids, while copper and metals below it do not. Carbon sits between aluminium and zinc, so metals below carbon, such as zinc and iron, can be extracted from their oxides by heating with carbon, whereas metals above carbon, such as aluminium, cannot be extracted this way. Including these non-metals turns the series into a ranking of tendency to form positive ions or, for carbon, tendency to take oxygen from a metal oxide.
A more reactive metal can displace a less reactive metal from a compound.
Displacement occurs when a more reactive metal takes the place of a less reactive metal in a compound. For example, magnesium placed in copper sulfate solution displaces copper, because magnesium is above copper in the reactivity series. The magnesium atoms lose electrons to form Mg²⁺ ions, which enter the solution, while Cu²⁺ ions gain electrons to form copper atoms. The blue colour fades and a pink-brown solid appears. The reverse, copper in magnesium sulfate solution, gives no reaction because copper is less reactive. Displacement is therefore evidence for the order of reactivity and can be used to deduce an order from experimental results.
Students should be able to: recall and describe the reactions, if any, of potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper with water or dilute acids and where appropriate, to place these metals in order of reactivity explain how the reactivity of metals with water or dilute acids is related to the tendency of the metal to form its positive ion deduce an order of reactivity of metals based on experimental results.
This outcome combines recall, explanation and deduction. Recall the reactions: potassium, sodium and lithium react with cold water to form the metal hydroxide and hydrogen, with potassium most vigorous; calcium reacts steadily with water; magnesium reacts very slowly with cold water but rapidly with dilute acid; zinc and iron react with dilute acid, zinc faster; copper reacts with neither. Place them K > Na > Li > Ca > Mg > Zn > Fe > Cu. Reactivity relates to the tendency to form a positive ion: the more readily a metal loses electrons to form a positive ion, the more reactive it is. Deduce an order from results by comparing the vigour of reactions or the outcomes of displacement experiments, then ranking the metals accordingly.
Your focus
- Describe how metal atoms form positive ions by losing electrons.
- Write the symbol and charge of the ion formed by a named metal.
- Explain why losing electrons produces a positively charged ion.
Show all 21 objectives
- Explain how the tendency to form positive ions determines a metal's reactivity.
- Use the idea of ion formation to compare the reactivity of two named metals.
- Predict whether a displacement reaction will occur and justify the prediction using reactivity.
- Recall the order of common metals in the reactivity series.
- Use evidence from reactions to place a metal in the reactivity series.
- Predict and explain displacement reactions using the reactivity series.
- Describe the reactions, if any, of the named metals with cold water and dilute acid.
- Place the named metals in order of reactivity using observed reactions.
- Explain that greater reactivity corresponds to a greater tendency to form a positive ion.
- State the positions of hydrogen and carbon in the reactivity series.
- Use the position of hydrogen to predict whether a metal reacts with dilute acid.
- Use the position of carbon to predict whether a metal oxide can be reduced by carbon.
- Describe displacement reactions between metals and compounds of other metals.
- Explain displacement in terms of transfer of electrons and formation of positive ions.
- Deduce an order of reactivity from displacement observations.
- Recall and describe the reactions of the named metals with water or dilute acids.
- Explain reactivity in terms of the tendency of a metal to form its positive ion.
- Deduce an order of reactivity from experimental results and use it to predict displacement.
The reactivity series exam tips
Marking Points
- Metal atoms lose electrons when they react, forming positive ions.
- The charge on the ion equals the number of electrons lost by the atom.
- Examples include Na⁺, Mg²⁺ and Al³⁺, with charges matching electrons lost.
- The loss of negatively charged electrons leaves more protons than electrons, giving a net positive charge.
- The tendency of a metal to form positive ions is linked to its position in the reactivity series.
- Reactivity increases as the tendency of a metal to form positive ions increases.
- Metals that lose electrons readily form positive ions easily and are more reactive.
- Metals that form positive ions only with difficulty are less reactive.
- The tendency to form positive ions explains observed reactions with water, acid and oxygen.
- Displacement occurs when a more reactive metal, which forms positive ions more readily, takes the place of a less reactive metal in a compound.
- Metals are arranged from most reactive to least reactive in a reactivity series.
- A typical order includes potassium, sodium, calcium, magnesium, aluminium, zinc, iron, copper, silver and gold.
- Evidence for the order comes from reactions with water, reactions with dilute acid and displacement reactions.
- A more reactive metal displaces a less reactive metal from a compound.
- The series can be used to predict whether a displacement reaction will occur.
- Potassium, sodium and lithium react with cold water to form the metal hydroxide and hydrogen, with potassium the most vigorous and lithium the least vigorous of the three.
- Calcium reacts steadily with water, forming calcium hydroxide, which is only slightly soluble and may appear as a white suspension, plus hydrogen.
- Magnesium reacts very slowly with cold water but rapidly with dilute acid, forming a salt and hydrogen.
- Zinc and iron do not react with cold water but react with dilute acid; zinc reacts faster than iron.
- Copper does not react with cold water or dilute acid under these conditions, so it is placed below iron.
- The order of reactivity is potassium, sodium, lithium, calcium, magnesium, zinc, iron, copper.
- Hydrogen is placed between lead and copper in the reactivity series.
- Metals above hydrogen displace hydrogen from dilute acids; metals below hydrogen, such as copper, do not.
- Carbon is placed between aluminium and zinc in the reactivity series.
- Metals below carbon can be extracted from their oxides by heating with carbon; metals above carbon cannot be extracted this way.
- The position of a non-metal in the series allows predictions about displacement and extraction.
- A more reactive metal displaces a less reactive metal from its compound.
- In the reaction, the more reactive metal forms positive ions that enter the solution.
- The less reactive metal is displaced and appears as a solid.
- Observations such as colour change, solid deposit or temperature change provide evidence of displacement.
- No reaction occurs when the metal is less reactive than the metal in the compound.
- Recall the reactions of potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper with water or dilute acid, including products and observations.
- Place the metals in order of reactivity: potassium, sodium, lithium, calcium, magnesium, zinc, iron, copper.
- Explain that greater reactivity corresponds to a greater tendency to form a positive ion by losing electrons.
- Deduce an order of reactivity from experimental results such as the rate of gas production, temperature change or displacement outcomes.
- Use the reactivity series to predict whether a displacement reaction will occur.
Examiner Tips
- 💡Use the group number of the metal to predict how many electrons are lost and therefore the ion charge.
- 💡Write the charge as a superscript after the symbol, for example Mg²⁺, and check the number of positive charges matches electrons lost.
- 💡If asked to explain, refer to loss of electrons and the resulting imbalance between protons and electrons.
- 💡When explaining a trend, use the phrase 'tendency to form positive ions' and link it to electron loss.
- 💡Support predictions with a displacement example, naming the more reactive metal that forms ions more readily.
- 💡Compare two named metals directly rather than describing reactivity in vague terms.
- 💡Learn the order in a memorable sequence and practise placing unfamiliar metals using given evidence.
- 💡For displacement questions, identify the free metal and the metal in the compound, then compare their positions.
- 💡When justifying a prediction, quote the relevant evidence, such as reaction with dilute acid or a displacement result.
- 💡When describing a reaction, name the metal, the reactant and the products, and include the observed sign such as fizzing, flame or gas bubbles.
- 💡Use the phrase 'under these conditions' when stating that a metal does not react, because reaction depends on the water or acid used.
- 💡To place metals in order, compare the vigour of their reactions rather than their physical appearance or density.
- 💡State the position of hydrogen or carbon relative to named metals when explaining a prediction.
- 💡Link the position of carbon to extraction: metals below carbon can be reduced by carbon, metals above cannot.
- 💡Use the series to justify a prediction rather than simply naming the more reactive substance.
- 💡Name both the metal and the compound when describing a displacement reaction.
- 💡Include the ionic equation or ion symbols to show which species gains and loses electrons.
- 💡Use the result of a displacement experiment to justify a position in the reactivity series.
- 💡When asked to deduce an order, compare the observations for each metal and state the ranking explicitly.
- 💡Link each reaction to the formation of a positive ion, for example Mg → Mg²⁺ + 2e⁻.
- 💡Use the phrase 'under these conditions' when a metal appears unreactive, and name the specific water or acid used.
Common Mistakes
- Writing ion charges without the correct magnitude, such as giving magnesium a 1⁺ charge; correct this by counting the electrons lost, so magnesium forms Mg²⁺.
- Saying metal atoms gain electrons to become positive ions; correct this by stating that metals lose electrons, since gaining electrons would give negative ions.
- Confusing the ion charge with the group number for every element without checking; correct this by working out electron loss from the atom's electron arrangement.
- Treating the reactivity series as an arbitrary list to memorise; correct this by explaining each position in terms of how readily the metal forms positive ions.
- Saying that more reactive metals form negative ions; correct this by stating that metals form positive ions, and reactivity relates to the ease of that formation.
- Assuming a less reactive metal cannot react at all; correct this by saying it forms positive ions less readily, so reactions are slower or need more energy.
- Placing copper above iron in the series; correct this by recalling that iron is more reactive than copper, so iron displaces copper from its compounds.
- Thinking the series is fixed by theory alone; correct this by linking each position to experimental evidence such as reaction with acid or water.
- Predicting displacement in the wrong direction, for example saying copper displaces zinc; correct this by checking that the free metal is above the metal in the compound.
- Assuming all metals react with cold water; correct this by stating that zinc, iron and copper do not react with cold water under these conditions.
- Placing calcium below magnesium because magnesium burns brightly in air; correct this by comparing reactions with water and dilute acid, where calcium reacts steadily with cold water but magnesium reacts very slowly.
- Writing that copper reacts slowly with dilute acid; correct this by stating that copper does not react with dilute acid under these conditions.
- Treating hydrogen and carbon as metals; correct this by stating that they are non-metals included in the series for prediction.
- Placing carbon above aluminium; correct this by placing carbon between aluminium and zinc.
- Claiming copper displaces hydrogen from dilute acid; correct this by stating that copper is below hydrogen and does not displace it.
- Saying the more reactive metal is displaced; correct this by stating that the more reactive metal displaces the less reactive metal.
- Writing that copper displaces magnesium from magnesium sulfate; correct this by stating that copper is less reactive and no reaction occurs.
- Ignoring the ionic explanation; correct this by stating that the more reactive metal forms positive ions and the less reactive metal ion gains electrons.
- Confusing the order of lithium and calcium; correct this by placing lithium above calcium because lithium reacts more vigorously with water.
- Stating that reactivity depends on the metal's density or melting point; correct this by linking reactivity to the tendency to form a positive ion.
- Deducing an order from a single observation without comparing vigour; correct this by comparing reactions across several metals under the same conditions.