1Metals in water
Some metals react with cold water. Calcium fizzes steadily, magnesium only very slowly, and copper not at all. The faster the reaction, the more reactive the metal.
reactive
Lesson 23.1 notes
The reactivity series
How metals react with water, acid and oxygen, and where carbon fits in.
2Metals in acid
Many metals react with dilute hydrochloric acid to give hydrogen. The balloon on the magnesium flask fills first. Copper gives no gas at all.
hydrogen
3Metals in a flame
Magnesium burns with a dazzling white flame and iron wool burns with sparks. Copper does not burn: its surface slowly turns black.
oxide
4The reactivity series
Putting the metals in order gives the reactivity series, from potassium, the most reactive, down to gold.
reactivity series
5Where carbon goes
Carbon is not a metal, but it goes in the series between aluminium and zinc. It can take oxygen from the oxides of metals below it.
carbon
6Gold stays shiny
Gold is so unreactive that a gold coin is still shiny after 2000 years in the ground, while an iron sword buried with it has rusted.
7Aluminium's hidden layer
Aluminium is quite reactive, but a thin, tough layer of aluminium oxide forms on its surface and protects it from water and air.
oxide layer
Explore: Reactivity lab
Test each metal with cold water, dilute acid and a flame. Fill in the results table and look for the order.
Common mistake: Reactivity is not the same as strength
Gold hardly reacts at all, yet it is soft; iron rusts, yet it is much harder. Reactivity is about how readily a metal reacts, not how strong or hard it is.
Remember
- The reactivity series: potassium, sodium, calcium, magnesium, aluminium, (carbon), zinc, iron, copper, silver, gold.
- More reactive metals react faster with water, acids and oxygen. Copper, silver and gold do not react with dilute hydrochloric or sulfuric acid.
- Carbon goes between aluminium and zinc: it can take oxygen from the oxides of the metals below it.
Going further at GCSE