KS3 · Chemistry

The reactivity series of metals

Potassium reacts with water more vigorously than any metal here, while gold is so unreactive it lies pure in the ground — one list explains both.

Chemistry · The reactivity series

Same six metals. Three different tests.

Pick a metal, then pick where it goes. Start with water, then try dilute acid, then oxygen.

Does this metal react with water?

Still to sort

Reacts with water (0)

Only the most reactive metals, right near the top.

Where the line is: Water only reaches the very top of the series. Potassium, sodium, lithium and calcium react; zinc and lead do not.

No reaction with water (0)

Everything below the top few metals.

Where the line is: Reacting with acid is not enough — the water line sits much higher up than the acid line.

6 of 6 still to sort.

Each card tells you where the metal sits in the series. Sort them by whether they react — then switch the test and sort the same six again. Watch where the dividing line falls each time.

Watch out: Hydrogen is the line for dilute acid only. Water stops much higher up the series, and oxygen reaches further down.

How do you know it reacted?

Three clues that a metal is reacting with acid
dilute acidthermometermetalsqueaky pop!

View: Metal reacting. Showing 4 layers: Test tube of dilute acid, Metal reacting, Thermometer — temperature risen, Lighted splint at the mouth

View

Layers

Explore

compare before and after

Now look for the three clues: bubbles, a higher reading, and a pop.

Switch between the two views, then tap each part to see what it tells you.

Building the order from evidence

Three metals, three clues

How vigorously each metal reacts with water

1 · Most vigorous3 · Least vigorous

  1. Lithium

    Clue: sodium reacts more vigorously with water than lithium does.

  2. Potassium

    Clue: potassium reacts more vigorously with water than sodium does.

  3. Sodium

    Clue: sodium reacts less vigorously with water than potassium does.

Writing word equations

Three reactions, three patterns

Write word equations for three reactions: zinc with dilute sulfuric acid, sodium with water, and magnesium burning in oxygen.

  1. Zinc and sulfuric acid are a metal and an acid, so use the pattern metal + acid → salt + hydrogen.
  2. missing step
Which line is step 2?

Getting metals out of the ground

Where it sits decides how you get it

Choose a branch to follow a metal's route.

Compared with carbon → How unreactive is it?

3 routes to a metal.

On A metal we want to obtain. 2 branches to choose from.

A metal that isn't found pure has to be extracted — often from its oxide. Follow each branch to see how a metal's position compared with carbon decides how it is obtained.

The two strangers in the list

What are carbon and hydrogen doing here?

Look at any reactivity series and you'll find two elements that are not metals at all: carbon, near the top, and hydrogen, towards the bottom.

Which is closest to what you think right now?
How sure are you?

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

One list that tells you which metals react with water, which react with acid — and which react with nothing at all.

What you need to know

  • The reactivity series lists metals from most reactive (top) to least reactive (bottom).
  • The order comes from evidence: comparing how vigorously metals react.
  • Water, dilute acid and oxygen each reach a different distance down the series.
  • Carbon and hydrogen are non-metals placed in the series as reference points.

The big picture

The reactivity series orders metals by how vigorously they react, most reactive at the top. Water, dilute acid and oxygen each react with metals down to a different point on it, and the non-metals carbon and hydrogen sit in the series as reference points for predicting acid reactions and how a metal is extracted.

Key points

1The higher a metal is in the reactivity series, the more vigorously it is likely to react.
2Only the most reactive metals near the top react with water: metal + water → metal hydroxide + hydrogen.
3Metals above hydrogen react with dilute acid: metal + acid → salt + hydrogen. Copper, silver and gold, below hydrogen, do not.
4Silver and the metals above it react with oxygen: metal + oxygen → metal oxide. Gold does not.
5Hydrochloric acid makes chlorides; sulfuric acid makes sulfates.
6Metals more reactive than carbon are extracted using electricity; metals less reactive than carbon can be displaced from their oxides by carbon.

Worked example

Problem

Calcium and copper are each dropped into dilute hydrochloric acid. Which one reacts? Write the word equation for the reaction that happens.

⚠ Watch out

Mixing up the products. Match the product to what the metal reacted with: acid gives a salt + hydrogen, water gives a metal hydroxide + hydrogen, and oxygen gives a metal oxide. Writing 'sodium oxide' for sodium and water is the classic slip.

🧠

Memory hook

Water skims the top, acid stops at hydrogen, oxygen goes all the way down to silver — and gold just sits there.

✓

Check yourself

Name a metal that reacts with water, one that reacts with dilute acid but not water, and one that reacts with nothing. What does each tell you about its place in the series?

Flashcards

(14)
What does the reactivity series show?
Metals in order of how vigorously they react compared with each other — most reactive at the top, least reactive at the bottom.
How can experiments put metals in order?
Compare how vigorously they react. More bubbles in the same dilute acid means more reactive (magnesium beats zinc). In water, potassium beats sodium, which beats lithium.
metal + acid → ?
salt + hydrogen
metal + water → ?
metal hydroxide + hydrogen. The hydroxide makes the solution alkaline.
metal + oxygen → ?
metal oxide
Which salt does hydrochloric acid make? Which does sulfuric acid make?
Hydrochloric acid → a chloride. Sulfuric acid → a sulfate. e.g. zinc + sulfuric acid → zinc sulfate + hydrogen.
What is effervescence?
Bubbles of gas being produced in a liquid — evidence that a gas is being made.
What does 'exothermic' mean, and how do you spot it?
Energy is transferred from the reaction to the surroundings. A thermometer shows the temperature rising.
How do you test for hydrogen?
Hold a lighted splint at the mouth of the tube. Hydrogen gives a squeaky pop.
How far down the series do water, dilute acid and oxygen each reach?
Water: only the top few metals. Dilute acid: down to hydrogen. Oxygen: down to silver. Gold reacts with none of them.
Why are the alkali metals stored under oil?
To stop them reacting with the oxygen and water in the air — they tarnish quickly.
How does carbon's position decide how a metal is extracted?
More reactive than carbon → extracted using electricity (electrolysis). Less reactive than carbon → carbon can displace the metal from its oxide.
Why is gold found pure in the ground?
It is so unreactive — at the very bottom of the series — that it is found uncombined in nature.
Why are carbon and hydrogen in the reactivity series?
They are non-metals placed there as reference points: hydrogen for which metals react with dilute acid, carbon for how a metal is extracted.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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