Why is "Writing the order the wrong way round (least reactive first)" a common mistake in Order of Reactivity?

Why it happens: Students rank correctly but forget the question asks for 'most reactive first'. How to avoid it: Re-read the instruction. The **most vigorous / fastest** reaction goes at the **top** of a 'most reactive first' list. A reversed order scores zero. Source: Edexcel Chemistry examiner reports — recurring error

Why is "Giving the order but not justifying it with the observations" a common mistake in Order of Reactivity?

Why it happens: Students treat it as a recall task and just write the list. How to avoid it: Quote the **evidence** for each position: 'A is most reactive because it fizzed fastest', 'D did not react so it is least reactive'. The justification carries the marks. Source: Edexcel Chemistry examiner reports

Why is "Getting the displacement rule backwards (thinking the displaced metal is more reactive)" a common mistake in Order of Reactivity?

Why it happens: Confusion over which metal 'wins'. How to avoid it: The metal that **does the displacing** (stays as the solid that pushes the other out) is the **MORE** reactive one. 'X displaces Y' means **X > Y**. Source: Edexcel Chemistry examiner reports

Why is "Treating a 'no reaction' result as useless / no information" a common mistake in Order of Reactivity?

Why it happens: Students think only a reaction tells them something. How to avoid it: A 'no reaction' (✗) is **positive evidence**: the added metal is **less reactive** than the metal in solution. Use every result. Source: Edexcel Chemistry examiner reports

Why is "Ranking metals from the memorised series instead of the data given" a common mistake in Order of Reactivity?

Why it happens: Students recall the standard series and ignore the actual results. How to avoid it: Answer from the **data in the question**. If letters (A, B, C, X) are used, only the observations can order them — the memorised series cannot. Source: Edexcel Chemistry examiner reports

Why is "Naming the gas from the water/acid test as oxygen or carbon dioxide" a common mistake in Order of Reactivity?

Why it happens: Students guess a common gas instead of recalling the reaction. How to avoid it: Metal + water/acid always gives **hydrogen** (squeaky-pop test). Never oxygen or CO₂. Source: Edexcel Chemistry examiner reports

Reactivity seriesEdexcel IGCSE Science(Double Award)-Chemistry (4WSD0-1C)

Order of Reactivity

Work through the notes, try the practice questions, then take the quiz. The report tells you exactly what to revise next.

Previous Next

Learn this Topic

Start with the slides for the quick version, then go deeper with the full study notes.

Detailed Notes

Full prose, callouts and a recap — built for A* mastery, not just a quick scan.

Take these study notes with you

Download a branded PDF — full prose, callouts, recap and memorise list for Order of Reactivity, ready to print or save offline.

Order of Reactivity — Edexcel International GCSE Science (Double Award) Chemistry (4WSD0-1C) Study Notes

The data-analysis skill of the reactivity series: how to DEDUCE the correct order of metals (most → least reactive) from experimental observations — reactions with water, dilute acid and oxygen, and from displacement results. The golden rule: the faster/more vigorous the reaction, the more reactive the metal; a metal that displaces another is more reactive than it. Covers Double Award Chemistry spec 2.15–2.16, assessed on Chemistry Paper 1 (4WSD0/1C).

What you’ll learn

Mapped to the Edexcel IGCSE 4WSD0-1C syllabus (2026 onwards).

2.15 — Deduce the order of reactivity of metals from their reactions with water, acid and oxygen.
2.16 — Use displacement-reaction results to place metals in order of reactivity.

The golden rule — vigour ranks the metals (spec 2.15)

More reactive = faster, more vigorous reaction. That single idea ranks every metal.

This subtopic is a data-analysis skill, not a memory test. You are given the results of experiments and asked to work out the order of reactivity — most reactive at the top, least reactive at the bottom.

The one rule that does it all:

The faster and more vigorous the reaction, the MORE reactive the metal.

So if metal A fizzes faster than metal B, then A is more reactive than B. If a metal shows no reaction, it is the least reactive of the set.

The same three reagents from the previous subtopic are your evidence:

Test	What 'more reactive' looks like
Water	faster fizzing; floats/moves/melts; bursts into flame
Dilute acid	faster bubbling; louder fizz; gets hot quickly
Oxygen (burning)	burns more easily, brighter, more vigorously

Reading the rate (the key idea). Examiners describe the rate in words you must rank:

violent / explosive > vigorous > rapid fizzing > steady fizzing > slow fizzing > very slow > no reaction.

The metal with the most violent description goes at the top; "no reaction" goes at the bottom.

Always quote the evidence. When you write the order, justify it: "A is most reactive because it fizzed fastest / burned most brightly." Examiners give marks for the reason, not just the list.

More reactive = faster + more vigorous reaction.
No reaction = least reactive of the set.
Rank the rate words: violent > vigorous > rapid > steady > slow > none.
Justify the order with the evidence (rate / vigour).

See the full worked example for order of reactivity →

Ordering from a results table (spec 2.15)

Compare the observations row by row, then list most → least reactive.

Most exam questions give a results table of three or four metals reacting with the same reagent (usually dilute acid). Your job: compare the observations and put the metals in order.

Same acid, four metals — rank by how vigorously each fizzes. Order: A > B > C > D.

Worked method — example table:

Metal	Observation with dilute acid
P	Many bubbles very quickly; tube gets hot
Q	Slow steady stream of bubbles
R	No bubbles at all
S	Bubbles rapidly (less than P, more than Q)

Step 1 — find the most reactive. P gives the fastest, most vigorous reaction → P is most reactive.

Step 2 — find the least reactive. R shows no reaction → R is least reactive.

Step 3 — order the middle. S is faster than Q → S above Q.

Order (most → least): P > S > Q > R.

Watch out for the gas. The bubbles in the acid (and water) tests are hydrogen — tested with a lit splint giving a squeaky pop. The amount/rate of hydrogen released is your measure of reactivity.

Compare observations of the SAME reagent across all metals.
Fastest/most vigorous → top; no reaction → bottom.
Order the middle metals by relative rate.
The gas is hydrogen (squeaky pop with a lit splint).

See the full worked example for order of reactivity →

Ranking from displacement results (spec 2.16)

If metal X displaces metal Y, then X is more reactive than Y. Build the order from the pattern of ticks.

A displacement reaction is a second, very reliable way to order metals. Put a metal into a solution of another metal's salt:

If metal X displaces metal Y from its solution, then X is MORE reactive than Y.

A more reactive metal pushes a less reactive metal out of solution (the reactive metal takes its place by losing electrons more readily). If no reaction happens, the added metal is less reactive than the one in solution.

A 'tick grid' is the classic question. Each ✓ = a reaction (displacement) happened; ✗ = no reaction.

Metal added ↓ / Solution →	copper(II) sulfate	iron(II) sulfate	zinc sulfate
copper	—	✗	✗
iron	✓	—	✗
zinc	✓	✓	—

How to read it. Count the ticks across each row — the metal that displaces the most others is the most reactive:

Zinc displaces copper AND iron → zinc is the most reactive.
Iron displaces copper only → iron is in the middle.
Copper displaces nothing → copper is the least reactive.

Order (most → least): zinc > iron > copper.

Iron displaces copper: the blue solution fades and a pink-brown copper layer forms — proof iron is more reactive than copper.

The reverse never happens. Copper added to iron(II) sulfate gives no reaction, because copper is less reactive than iron — it cannot push iron out. A "no reaction" result is just as useful as a tick: it tells you the added metal is the less reactive one.

Observations that prove a displacement happened:

the solution colour changes (e.g. blue CuSO₄ fades);
a coating / deposit of the displaced metal forms on the added metal;
sometimes the mixture warms up (the reaction is exothermic).

X displaces Y ⇒ X is MORE reactive than Y.
No reaction ⇒ added metal is LESS reactive.
Count ticks across each row: most ticks = most reactive.
Evidence: colour fades, metal deposit forms, mixture warms.

See the full worked example for order of reactivity →

Placing an unknown metal X (spec 2.15–2.16)

Slot the unknown between the metals it does / doesn't react with.

A favourite stretch question gives an unknown metal X and some results, then asks where X fits in a list of known metals.

The method — 'between' logic:

Find the most reactive metal X does react with / displaces → X is more reactive than that one.
Find the least reactive metal X does NOT react with / fails to displace → X is less reactive than that one... and slot X between them.

Example. Known order so far: magnesium > zinc > iron > copper. Metal X is tested:

Test	Result
X + zinc sulfate solution	✗ no reaction
X + iron(II) sulfate solution	✓ displaces iron
X + copper(II) sulfate solution	✓ displaces copper

Reasoning.

X does not displace zinc → X is less reactive than zinc.
X does displace iron → X is more reactive than iron.
Therefore X sits between zinc and iron.

Order: magnesium > zinc > X > iron > copper.

Identifying X. If the question then asks you to name X, match its position to a known metal with the right behaviour (here X behaves like a metal between zinc and iron — e.g. it could be a metal such as tin if other clues fit). Always justify with the displacement evidence.

X reacts with / displaces a metal ⇒ X is above it.
X fails to react with a metal ⇒ X is below it.
Slot X BETWEEN the two — above what it displaces, below what it doesn't.
Justify the position with the displacement evidence.

See the full worked example for order of reactivity →

How it’s examined

Double Award Chemistry is assessed on one untiered paper — Chemistry Paper 1 (4WSD0/1C), 2 hours, 110 marks, 33.3% of the Double Award (calculator allowed). Order-of-reactivity items are pure data analysis: you are given a results table (reactions with water/acid/oxygen, or a displacement tick grid) and asked to deduce the order most → least reactive (3–4 marks), to justify the order with the evidence, or to place an unknown metal X in the series (the high-mark stretch question). The marks are won by quoting the evidence — 'fastest fizzing', 'displaces copper', 'no reaction' — not by reciting the standard series from memory.

Sources: Pearson Edexcel International GCSE Science (Double Award) 4SD0 specification — Issue 4 (valid for 2026 onwards); Pearson Edexcel International GCSE Chemistry 4CH1 specification — Issue 4 (shared Chemistry Paper 1 content); Pearson Edexcel 4SD0 / 4CH1 examiner reports 2022–2024. Last reviewed 2026-06-07.

Master this Topic

Worked examples, formulae, definitions and the mistakes examiners flag — everything you need to push from a pass to an A*.

Take this whole topic with you

Download a branded revision sheet — worked examples, formulae, definitions and common mistakes for Order of Reactivity, ready to print or save as PDF.

Step-by-step worked examples — Order of Reactivity

Step-by-step solutions to past-paper-style questions on order of reactivity, written exactly the way a tutor would explain them at the board.

1Order three metals from acid observations (Getting started)
Getting started• 4WSD0/1C style — short answer• reactivity, spec-2.15, data
Question
Three metals are added to separate test tubes of dilute hydrochloric acid. X: bubbles slowly. Y: bubbles very rapidly, tube gets hot. Z: no bubbles. Put the metals in order from most to least reactive. (2 marks)
Step-by-step solution
1. Step 1
  Most reactive (1). Y reacts fastest and most vigorously (very rapid bubbling, gets hot) → Y is most reactive.
2. Step 2
  Least reactive (1). Z shows no reaction → Z is least reactive.
3. Step 3
  Middle. X bubbles slowly — between Y and Z.
Answer
Most reactive → least reactive: Y > X > Z.
Examiner tip
Rank by the RATE of reaction: fastest fizz = most reactive, no reaction = least reactive. Don't try to name the metals — the order is all that's asked.
2Use the water test to spot the most reactive (Getting started)
Getting started• 4WSD0/1C style — short answer• reactivity, spec-2.15, water
Question
Four metals are each placed in cold water. Only metal W fizzes and gives off a gas; the other three show no reaction. (a) What does this tell you about W? (b) What gas is given off? (2 marks)
Step-by-step solution
1. Step 1
  (a) (1). W is the most reactive of the four — it is the only one reactive enough to react with cold water.
2. Step 2
  (b) (1). The gas is hydrogen (metal + water → metal hydroxide + hydrogen).
3. Step 3
  Test for it. A lit splint gives a squeaky pop to confirm hydrogen.
Answer
(a) W is the most reactive metal of the four (only one to react with cold water); (b) hydrogen.
Examiner tip
Only the most reactive metals react with cold water. The gas is always hydrogen — and the squeaky-pop test is a common follow-up mark.
3Order metals from a displacement tick grid (Building confidence)
Building confidence• 4WSD0/1C style — structured• displacement, spec-2.16, data
Question
Each metal is added to solutions of the other metals' sulfates. ✓ = reaction, ✗ = no reaction.

| added ↓ / solution → | A sulfate | B sulfate | C sulfate | | C | ✓ | ✓ | — | | A | — | ✗ | ✗ | | B | ✓ | — | ✗ |

Put A, B and C in order from most to least reactive. (3 marks)
Step-by-step solution
1. Step 1
  Count ticks per row (1). C displaces A and B (2 ticks); B displaces A only (1 tick); A displaces nothing (0 ticks).
2. Step 2
  Apply the rule (1). A metal that displaces another is more reactive than it. Most ticks = most reactive → C is most reactive, A is least reactive.
3. Step 3
  Order the middle (1). B displaces A but is displaced by C → B sits between them.
Answer
Most reactive → least reactive: C > B > A.
Examiner tip
The quickest method is to count ✓ across each row. 'X displaces Y means X is more reactive than Y' — state this rule to secure the reasoning mark.
4Justify an order with evidence (Building confidence)
Building confidence• 4WSD0/1C style — structured• reactivity, spec-2.15, reasoning
Question
Magnesium, zinc and copper are each added to dilute acid. Magnesium fizzes vigorously, zinc fizzes steadily and copper does not react. State the order of reactivity and explain how the observations support it. (3 marks)
Step-by-step solution
1. Step 1
  Order (1). Magnesium > zinc > copper.
2. Step 2
  Link rate to reactivity (1). Magnesium fizzes most vigorously, so it is the most reactive; zinc fizzes more slowly, so it is less reactive than magnesium.
3. Step 3
  No reaction = least reactive (1). Copper does not react with the acid, so it is the least reactive of the three.
Answer
Order: magnesium > zinc > copper. Magnesium fizzes most vigorously (most reactive), zinc fizzes steadily (less reactive), and copper shows no reaction (least reactive).
Examiner tip
The marks are for the JUSTIFICATION, not just the list. Tie each metal's position to its specific observation ('fizzes most vigorously', 'no reaction').
5Place an unknown metal X in the series (Stretch)
Stretch• 4WSD0/1C style — extended• displacement, spec-2.16, unknown
Question
The order zinc > iron > copper is known. An unknown metal X is tested: X displaces copper from copper(II) sulfate; X displaces iron from iron(II) sulfate; X does NOT react with zinc sulfate. Place X in the order and explain your reasoning. (4 marks)
Step-by-step solution
1. Step 1
  Displaces copper (1). X displaces copper → X is more reactive than copper.
2. Step 2
  Displaces iron (1). X displaces iron → X is more reactive than iron.
3. Step 3
  No reaction with zinc (1). X does not displace zinc → X is less reactive than zinc.
4. Step 4
  Slot X between (1). X is below zinc but above iron → it sits between zinc and iron.
Answer
Order: zinc > X > iron > copper. X is less reactive than zinc (no reaction) but more reactive than iron and copper (it displaces both).
Examiner tip
Use 'between' logic: X is above everything it displaces and below anything it can't displace. State each displacement result as evidence — every result is worth a mark.
6Identify an unknown metal from observations (Stretch)
Stretch• 4WSD0/1C style — extended• reactivity, spec-2.15, spec-2.16, identify
Question
A metal Q reacts steadily with dilute acid (slower than magnesium but faster than iron), and it displaces copper and lead from their solutions but does NOT displace iron. Using the order magnesium > zinc > iron > tin > lead > copper, identify Q and justify your answer. (4 marks)
Step-by-step solution
1. Step 1
  Faster than iron, slower than magnesium (1). Q sits below magnesium but above iron in reactivity based on the acid rate.
2. Step 2
  Does not displace iron (1). Wait — Q does not displace iron, so Q is less reactive than iron? Re-check: a metal that does NOT displace iron is below iron. Combine the clues carefully.
3. Step 3
  Resolve the evidence (1). Q displaces copper and lead (so Q is above both) but not iron (so Q is below iron). Q therefore sits between iron and lead/copper → Q is tin (the metal between iron and lead in the given order).
4. Step 4
  Justify (1). Tin > tin's position fits: above lead and copper (it displaces them) and below iron (it does not displace iron).
Answer
Q is tin — it displaces copper and lead (so is more reactive than both) but not iron (so is less reactive than iron), placing it between iron and lead, which matches tin.
Examiner tip
When a question mixes acid-rate clues and displacement clues, the DISPLACEMENT results are the most reliable — 'does not displace iron' firmly places the metal below iron. Always reconcile all the evidence before naming the metal.

Model Answers — Order of Reactivity

High-scoring sample answers for order of reactivity on the Pearson Edexcel IGCSE Chemistry Paper 1 (4WSD0/1C) paper, with examiner-style notes mapping each response to the mark scheme and assessment objectives.

Question 1
4WSD0/1C style2 marks
State how you can tell, from its reaction with dilute acid, which of two metals is more reactive. (2 marks)
Model answer
The more reactive metal reacts faster / more vigorously — it produces bubbles (of hydrogen) more quickly. (1)

The less reactive metal reacts more slowly, or not at all. (1)
Why this scores
1 mark for linking 'more reactive' to 'faster / more vigorous'; 1 mark for the comparison. The word 'faster' (rate) is the key idea examiners look for.
Question 2
4WSD0/1C style2 marks
Three metals react with water as follows — L: violent fizzing, floats and moves; M: no reaction; N: slow fizzing. Put L, M and N in order of reactivity, most reactive first. (2 marks)
Model answer
Most reactive is L — it reacts most violently (fizzes, floats, moves). (1)

Least reactive is M — it shows no reaction with water; N (slow fizzing) is in between.

Order: L > N > M. (1)
Why this scores
Rank strictly by the vigour of the reaction. 'No reaction' always goes at the bottom. A reversed order scores zero, so double-check direction (most reactive first).
Question 3
4WSD0/1C style4 marks
A student adds metal P to a solution of metal R's salt and sees a reaction (a deposit forms and the solution colour fades). Adding metal R to a solution of metal P's salt gives no reaction. State which metal is more reactive and explain how the results show this. (4 marks)
Model answer
P is more reactive than R. (1)

P displaces R from its salt solution — a more reactive metal displaces a less reactive one. (1)

Evidence: a deposit of R forms and the solution colour fades, showing R has been pushed out of solution by P. (1)

The reverse (R added to P's solution) gives no reaction, because R is less reactive and cannot displace P. (1)
Why this scores
Marks for: correct conclusion; the displacement rule stated; the supporting observation; and using the 'no reaction' result. A 'no reaction' result is positive evidence — it confirms the order, so always use it.
Question 4
4WSD0/1C style4 marks
Three metals D, E and F are tested. With dilute acid: D fizzes rapidly, E fizzes very slowly, F does not react. With oxygen: D burns brightly, E oxidises slowly, F does not burn. Deduce the order of reactivity and explain how both sets of results support it. (4 marks)
Model answer
Order: D > E > F. (1)

Acid evidence: D fizzes most rapidly (most reactive), E fizzes very slowly (less reactive), F gives no reaction (least reactive). (1)

Oxygen evidence: D burns most brightly/vigorously (most reactive), E oxidises only slowly, and F does not burn at all (least reactive). (1)

Both tests agree — the same order is obtained from the acid reactions and the oxygen reactions, which makes the conclusion reliable. (1)
Why this scores
When two independent tests give the same order, say so — it earns the evaluation mark. Always justify each position with the matching observation from BOTH tests.
Question 5
4WSD0/1C style — extended6 marks
Metals G, H, J and K are each added to solutions of the others' sulfates. ✓ = reaction; ✗ = none. G displaces H, J and K. H displaces J and K. J displaces K only. K displaces none. (a) Place the four metals in order of reactivity, most reactive first. (b) Explain, using one of the results, how you know G is more reactive than K. (6 marks)
Model answer
(a) Order: G > H > J > K. (3)

G displaces three metals (the most) → most reactive. (1)

K displaces none → least reactive. (1)

H displaces two and J displaces one, so H is above J → G > H > J > K. (1)

(b) G more reactive than K (3).

G displaces K from a solution of K's sulfate. (1)

A more reactive metal displaces a less reactive metal from solution. (1)

Therefore, because G displaces K, G must be more reactive than K (a deposit of K forms and the solution changes as G takes K's place). (1)
Why this scores
Part (a): count ticks per metal — most displacements = most reactive. Part (b): you MUST quote a specific result (G displaces K) and link it to the displacement rule. Generic statements without the result lose the explanation marks.
Question 6
4WSD0/1C style — extended7 marks
The order calcium > magnesium > zinc > iron > copper is known. An unknown metal T is tested: T reacts slowly with cold water (slower than magnesium); T displaces zinc, iron and copper from their solutions; T does NOT displace magnesium. (a) Place T in the order, explaining your reasoning. (b) State one observation that would be seen when T is added to copper(II) sulfate solution. (7 marks)
Model answer
(a) Order: calcium > magnesium > T > zinc > iron > copper. (5)

T reacts with cold water (only quite reactive metals do this), so T is near the top of the series. (1)

T displaces zinc, iron and copper → T is more reactive than all three. (1)

T does NOT displace magnesium → T is less reactive than magnesium. (1)

T reacts more slowly with water than magnesium, supporting that it is below magnesium. (1)

Combining the evidence, T sits between magnesium and zinc. (1)

(b) Observation with copper(II) sulfate (2).

The blue colour of the solution fades (Cu²⁺ being removed / replaced). (1)

A pink-brown deposit of copper forms on the surface of metal T. (1)
Why this scores
Use 'between' logic: T is below the most reactive metal it CANNOT displace (magnesium) and above everything it CAN displace (zinc, iron, copper). For part (b), the colour fade AND the copper deposit are the two standard displacement observations — give both for full marks.

Key Definitions and Keywords — Order of Reactivity

Definitions to memorise and the exact keywords mark schemes credit for order of reactivity answers — sharpened from recent examiner reports for the 2026 Pearson Edexcel IGCSE Chemistry Paper 1 (4WSD0/1C) sitting.

Reactivity (of a metal)
Examiner keyword
How readily a metal reacts — measured by how fast and how vigorously it reacts with water, acid or oxygen. The more vigorous the reaction, the more reactive the metal.
Order of reactivity
Examiner keyword
A list of metals arranged from most reactive (top) to least reactive (bottom), deduced from experimental observations.
Reactivity series
The standard ordered list of metals by reactivity, used to predict reactions with water, acid and metal-salt solutions.
Displacement reaction
Examiner keyword
A reaction in which a more reactive metal takes the place of a less reactive metal in a compound or solution. If metal X displaces metal Y, X is more reactive than Y.
More reactive
Examiner keyword
A metal that reacts faster/more vigorously, or that displaces another metal from its solution.
Vigorous reaction
A fast, energetic reaction — e.g. rapid fizzing, getting hot, bright burning. Higher vigour indicates a more reactive metal.
No reaction
When a metal shows no change with a reagent — evidence that it is the least reactive of the set being tested.
Rate of reaction
How quickly a reaction proceeds (e.g. how fast bubbles form). A faster rate with the same reagent means a more reactive metal.
Test for hydrogen
Examiner keyword
Hold a lit splint at the mouth of the tube; a 'squeaky pop' confirms hydrogen — the gas given off when reactive metals react with water or acid.
Deposit (in displacement)
The solid layer of displaced (less reactive) metal that forms on the added metal — visible evidence that a displacement reaction has occurred.

Common Mistakes and Misconceptions — Order of Reactivity

The traps other students keep falling into on order of reactivity questions — taken from recent Pearson Edexcel IGCSE Chemistry Paper 1 (4WSD0/1C) examiner reports and mark schemes — and how to avoid them.

✕Writing the order the wrong way round (least reactive first)
Edexcel Chemistry examiner reports — recurring error
Why it happens
Students rank correctly but forget the question asks for 'most reactive first'.
How to avoid it
Re-read the instruction. The most vigorous / fastest reaction goes at the top of a 'most reactive first' list. A reversed order scores zero.
✕Giving the order but not justifying it with the observations
Edexcel Chemistry examiner reports
Why it happens
Students treat it as a recall task and just write the list.
How to avoid it
Quote the evidence for each position: 'A is most reactive because it fizzed fastest', 'D did not react so it is least reactive'. The justification carries the marks.
✕Getting the displacement rule backwards (thinking the displaced metal is more reactive)
Edexcel Chemistry examiner reports
Why it happens
Confusion over which metal 'wins'.
How to avoid it
The metal that does the displacing (stays as the solid that pushes the other out) is the MORE reactive one. 'X displaces Y' means X > Y.
✕Treating a 'no reaction' result as useless / no information
Edexcel Chemistry examiner reports
Why it happens
Students think only a reaction tells them something.
How to avoid it
A 'no reaction' (✗) is positive evidence: the added metal is less reactive than the metal in solution. Use every result.
✕Ranking metals from the memorised series instead of the data given
Edexcel Chemistry examiner reports
Why it happens
Students recall the standard series and ignore the actual results.
How to avoid it
Answer from the data in the question. If letters (A, B, C, X) are used, only the observations can order them — the memorised series cannot.
✕Naming the gas from the water/acid test as oxygen or carbon dioxide
Edexcel Chemistry examiner reports
Why it happens
Students guess a common gas instead of recalling the reaction.
How to avoid it
Metal + water/acid always gives hydrogen (squeaky-pop test). Never oxygen or CO₂.

Past paper style quiz

Get a report showing which sub-topics you've nailed and which ones still need work.

Order of Reactivity — Edexcel International GCSE Science (Double Award) Chemistry (4WSD0-1C) Study Notes

Test

What 'more reactive' looks like

Water

faster fizzing; floats/moves/melts; bursts into flame

Dilute acid

faster bubbling; louder fizz; gets hot quickly

Oxygen (burning)

burns more easily, brighter, more vigorously

Metal

Observation with dilute acid

Many bubbles very quickly; tube gets hot

Slow steady stream of bubbles

No bubbles at all

Bubbles rapidly (less than P, more than Q)

Metal added ↓ / Solution →

copper(II) sulfate

iron(II) sulfate

zinc sulfate

copper

—

✗

iron

✓

—

✗

zinc

✓

—

Test

Result

X + zinc sulfate solution

✗ no reaction

X + iron(II) sulfate solution

✓ displaces iron

X + copper(II) sulfate solution

✓ displaces copper

Order of Reactivity

Detailed Notes

What you’ll learn

How it’s examined

1Order three metals from acid observations (Getting started)

2Use the water test to spot the most reactive (Getting started)

3Order metals from a displacement tick grid (Building confidence)

4Justify an order with evidence (Building confidence)

5Place an unknown metal X in the series (Stretch)

6Identify an unknown metal from observations (Stretch)

Reactivity (of a metal)

Order of reactivity

Reactivity series

Displacement reaction

More reactive

Vigorous reaction

No reaction

Rate of reaction

Test for hydrogen

Deposit (in displacement)

✕Writing the order the wrong way round (least reactive first)

✕Giving the order but not justifying it with the observations

✕Getting the displacement rule backwards (thinking the displaced metal is more reactive)

✕Treating a 'no reaction' result as useless / no information

✕Ranking metals from the memorised series instead of the data given

✕Naming the gas from the water/acid test as oxygen or carbon dioxide

Past paper style quiz

Order of Reactivity

Detailed Notes

What you’ll learn

How it’s examined

1Order three metals from acid observations (Getting started)

2Use the water test to spot the most reactive (Getting started)

3Order metals from a displacement tick grid (Building confidence)

4Justify an order with evidence (Building confidence)

5Place an unknown metal X in the series (Stretch)

6Identify an unknown metal from observations (Stretch)

Reactivity (of a metal)

Order of reactivity

Reactivity series

Displacement reaction

More reactive

Vigorous reaction

No reaction

Rate of reaction

Test for hydrogen

Deposit (in displacement)

✕Writing the order the wrong way round (least reactive first)

✕Giving the order but not justifying it with the observations

✕Getting the displacement rule backwards (thinking the displaced metal is more reactive)

✕Treating a 'no reaction' result as useless / no information

✕Ranking metals from the memorised series instead of the data given

✕Naming the gas from the water/acid test as oxygen or carbon dioxide

Past paper style quiz