Why Some Metals React and Some Do Not
- Chemistry
- Ages 11–14 · Grades 6–8
- Hands-on experiment
What you’ll find out
- Metals differ enormously in how readily they react.
- The reactivity series puts them in a fixed, testable order.
- How a metal is used follows directly from where it sits in that order.
No sign-up and no real names. In the lesson you check your understanding as you read, run the experiment yourself, and practise until it sticks.
Not all metals behave alike
Metals look much alike — shiny, hard, good conductors — so it is easy to assume they behave alike. They do not. Drop a strip of magnesium into dilute acid and it fizzes vigorously at once. Drop a strip of copper into the same acid, on the same day, and nothing whatever happens. Not slowly: nothing. That is not a small difference in degree. It is the difference between a metal that reacts and one that does not.
The order is the useful part
Test enough metals and something useful emerges: they always come out in the same order. Potassium near the top, then magnesium, then zinc, then iron, with copper low down and gold near the bottom. That list is called the reactivity series, and it earns its place by predicting things rather than just describing them. It tells you which metals are found in the ground as ore and which are found as lumps of pure metal. Gold turns up pure precisely because it does not react with anything around it. Iron turns up combined with oxygen, because it does.
Curriculum links: NGSS MS-PS1-2