Put metals in water, steam and acid and rank them by how fast they react. The resulting order, the reactivity series, predicts which metal will push another out of its compounds and how each metal must be extracted.
The reactivity series, from most to least reactive, is: potassium, sodium, calcium, magnesium, aluminium, (carbon), zinc, iron, (hydrogen), copper, silver, gold. It is worked out from reactions with cold water, steam and dilute acids. A more reactive metal displaces a less reactive metal from a solution of its salt. Extended: the more reactive the metal, the more easily it loses electrons to form positive ions. Aluminium appears unreactive because of its protective oxide layer.
The same three tests put the metals in order.
| Metal | Cold water | Steam | Dilute hydrochloric acid |
|---|---|---|---|
| potassium, sodium, calcium | react (hydroxide + H2) | violent | violent (dangerous) |
| magnesium | very slow | reacts (oxide + H2) | fast fizzing |
| zinc, iron | no reaction | react when hot | steady fizzing |
| copper, silver, gold | no reaction | no reaction | no reaction |
Four quick checks. Each correct answer earns XP and records this skill on your profile.
Which metal is the most reactive?
Which metal reacts with steam but only very slowly with cold water?
Iron is placed in copper(II) sulfate solution. What happens?
Which metal does not react with dilute hydrochloric acid?
Put metals into solutions of other metals' salts in the simulator. Watch the more reactive metal hand electrons to the ions of the less reactive one.
Aluminium is high in the series but often seems unreactive, for example it does not react with water. That is because its surface is sealed by a layer of aluminium oxide, not because it is low in the series. Remove the layer and it reacts vigorously.
Unlocks once the four checks above are done. Worth more XP, written to IGCSE Paper 2 and Paper 4 standard.
Which mixture would react?
(Extended) Why is magnesium more reactive than iron?
(Extended) Which is the ionic equation for the reaction between magnesium and copper(II) sulfate solution?
Why does aluminium not appear to react with water, although it is above zinc in the reactivity series?
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