AQA GCSE Chemistry Foundation (8462), Foundation tier · Chemical changes › Reactivity of metals
Practise The reactivity series. 7 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
How metals are ranked by how readily they react, how this links to forming positive ions, and how a more reactive metal displaces a less reactive one. Questions often give observations from an experiment and ask you to put metals in order or predict whether a reaction happens.
Key facts
K > Na > Li > Ca > Mg > C > Zn > Fe > H > Cu
metal + water → metal hydroxide + hydrogen
metal + acid → salt + hydrogen
A more reactive metal displaces a less reactive metal from its compound
Reactivity = tendency of a metal to form its positive ion
Copper does not react with water or with dilute hydrochloric or sulfuric acid
Hydrogen test: lit splint → squeaky pop
Notes
The reactivity series
diagram
Metals can be put in order of reactivity. The order you need, most reactive first: potassium, sodium, lithium, calcium, magnesium, zinc, iron, copper.
The non-metals carbon and hydrogen are often included: carbon goes between magnesium and zinc, and hydrogen goes between iron and copper.
Most reactive at the top. Carbon and hydrogen (blue) are non-metals placed in the series for comparison.
When metals react, their atoms lose electrons and form positive ions. The more easily a metal forms its positive ion, the more reactive it is.
Reactions with water and dilute acids
Potassium, sodium and lithium react with cold water, fizzing and moving about on the surface: metal + water → metal hydroxide + hydrogen. Potassium reacts so violently that the hydrogen catches fire with a lilac flame.
Calcium reacts steadily with cold water. Magnesium reacts only very slowly with cold water. Zinc, iron and copper show no visible reaction with cold water.
With dilute acids: metal + acid → salt + hydrogen. Magnesium fizzes quickly, zinc steadily and iron slowly. Copper does not react with dilute hydrochloric or sulfuric acid.
Calcium reacts very vigorously with dilute acids. Potassium, sodium and lithium react dangerously fast with acids, so these reactions are not done in school.
Test for hydrogen: a lit splint gives a squeaky pop.
Displacement reactions
A more reactive metal displaces a less reactive metal from its compound, e.g. from a solution of its salt.
Example: magnesium + copper sulfate → magnesium sulfate + copper. The blue colour fades, a pink-brown coating of copper forms and the mixture gets warmer.
If the metal added is less reactive, nothing happens, e.g. copper + zinc sulfate: no reaction.
You can find an order of reactivity by adding each metal to solutions of the other metals' salts and seeing which ones react.
How to answer each type of question
Put metals in order of reactivity from results
1 to 3 marksGrade 4
Find the measure of how vigorous each reaction was: bubbles, time to disappear, temperature rise.
More vigorous means more reactive.
Write the order in the direction the question asks (most or least reactive first).
Example. A student added equal-sized pieces of four metals, W, X, Y and Z, to dilute hydrochloric acid.
Metal
Observation
W
steady fizzing
X
no bubbles
Y
very rapid fizzing
Z
a few slow bubbles
(a) Put the metals in order of reactivity, most reactive first. (b) Which metal could be copper? Give a reason.Show the model answerHide the model answer
(a) Y, W, Z, X (1) (b) X (1) because copper does not react with dilute hydrochloric acid / copper is less reactive than hydrogen (1)
Describe the reaction of a metal with water
2 to 3 marksGrade 4
Give what you would see: fizzing, floating, moving, melting, getting smaller.
Name both products: the metal hydroxide and hydrogen.
Example. A small piece of sodium is added to a trough of water. Describe what you would see and name the products.
Show the model answerHide the model answer
Fizzing / bubbles (1) Floats and moves around / melts into a ball / gets smaller and disappears (1) Products: sodium hydroxide and hydrogen (1)
Predict and explain a displacement reaction
2 to 4 marksGrade 5
Find both metals in the reactivity series.
If the solid metal is more reactive than the metal in the compound, it displaces it.
Name the products; if it is less reactive, say 'no reaction' and give the reason.
Example. A piece of zinc is placed in blue copper sulfate solution. (a) Explain why a reaction happens. (b) Write a word equation for the reaction. (c) Predict what happens when copper is placed in zinc sulfate solution.
Show the model answerHide the model answer
(a) Zinc is more reactive than copper (1) so zinc displaces copper from copper sulfate (1) (b) zinc + copper sulfate → zinc sulfate + copper (1) (c) No reaction, because copper is less reactive than zinc (1)
Don’t lose marks
Putting lithium above sodium or potassium.
Saying copper reacts with dilute acid to give hydrogen.
Giving the metal oxide as the product with cold water: it is the metal hydroxide.
Writing 'hydrogen is produced' when asked what you would see: say 'fizzing' or 'bubbles'.
Predicting a displacement when the metal added is less reactive than the metal in the compound.
More tips
Memory tricks
Mnemonic for the order: Please Send Lions, Cats, Monkeys, Cute Zebras In Hot Countries (K, Na, Li, Ca, Mg, C, Zn, Fe, H, Cu).
Reactivity increases down Group 1, so potassium > sodium > lithium.
Displacement: the more reactive metal 'steals' the other metal's partner in the compound.
Anything below hydrogen (copper here) does not give hydrogen with dilute acids.
Exam technique
'Describe what you would see' means observations: bubbles, the metal disappearing, colour changes, getting warm.
When you deduce an order, quote the evidence, e.g. 'Y gave the most bubbles'.
For a fair comparison, keep the size of metal pieces, the acid concentration and volume, and the temperature the same.
What each grade needs
What you need to be able to do, from the first marks up to the top grade.
Grade 3
Recall the order of the reactivity seriesPotassium, sodium, lithium, calcium, magnesium, (carbon), zinc, iron, (hydrogen), copper, from most to least reactive.
Grade 4
Describe metal reactions with water and acidSay what you would see, e.g. fizzing, and name the products (metal hydroxide or salt, plus hydrogen).
Grade 5
Deduce an order of reactivity from resultsThe more vigorous the reaction (more bubbles, bigger temperature rise), the more reactive the metal.
Grade 5
Predict whether a displacement reaction happensA metal displaces another metal from its compound only if it is more reactive.
Quick recall
Cover the answers and test yourself. The app has these as flashcards that come back just before you'd forget them.
Zinc reacts with dilute hydrochloric acid, but copper does not. Name the gas produced when zinc reacts with the acid.
hydrogen
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy3 marks
The reactivity series lists metals in order of reactivity.
(a) Which list shows these metals in order of decreasing reactivity (most reactive first)? Tick (✓) one box.[1]
potassium, zinc, iron, copper
copper, iron, zinc, potassium
zinc, potassium, copper, iron
iron, copper, potassium, zinc
(b) Zinc reacts with dilute hydrochloric acid, but copper does not. Name the gas produced when zinc reacts with the acid.[1]
(c) Explain, in terms of the ions that metals form, why zinc is more reactive than copper.[1]
Show the answer and mark scheme
(a)Answer: potassium, zinc, iron, copper
(b)Answer: hydrogen
hydrogen
(c)
zinc has a greater tendency than copper to form positive ions (to lose electrons)
Question 2Medium6 marks
When metals react with other substances the metal atoms form positive ions.
(a) Which metal forms positive ions most easily? Tick (✓) one box.[1]
Calcium
Copper
Iron
Zinc
(b) Explain why potassium is more reactive than magnesium. Use ideas about ions in your answer.[2]
(c) Describe what you would see when a small piece of calcium is added to cold water.[2]
(d) Hydrogen is often included in the reactivity series. Copper does not react with dilute acids. Should hydrogen be placed above or below copper in the reactivity series? Give a reason.[1]
Show the answer and mark scheme
(a)Answer: Calcium
(b)
potassium atoms lose electrons / form positive ions more easily than magnesium atoms
so potassium reacts more vigorously / faster (with water and acids)
(c)
fizzing / bubbles of gas
the calcium gets smaller / disappears
the solution turns cloudy / milky
(d)
above copper, because copper does not displace hydrogen from acids