Evidence for the reactivity series
In a reactivity series, the most reactive elementA substance made of one type of atom only. is placed at the top and the least reactive element at the bottom. More reactive metals have a greater tendency to lose electronSubatomic particle, with a negative charge and a negligible mass relative to protons and neutrons. and form positive ionElectrically charged particle, formed when an atom or molecule gains or loses an electron/electrons..
The reactivity series of metals
A good way to remember the order of a reactivity series of metals is to use the first letter of each one to make up a silly sentence. For example: People Say Little Children Make AZebra Ill Constantly Sniffing Giraffes.
Observations of the way that these elements react with water, acidCorrosive substance which has a pH lower than 7. Acidity is caused by a high concentration of hydrogen ions. and steam enable us to put them into this series.
The tables show how the elements react with water and dilute acids:
| Element | Reaction with water |
| Potassium | Violently |
| Sodium | Very quickly |
| Lithium | Quickly |
| Calcium | More slowly |
| Element | Potassium |
|---|---|
| Reaction with water | Violently |
| Element | Sodium |
|---|---|
| Reaction with water | Very quickly |
| Element | Lithium |
|---|---|
| Reaction with water | Quickly |
| Element | Calcium |
|---|---|
| Reaction with water | More slowly |
| Element | Reaction with dilute acids |
| Calcium | Very quickly |
| Magnesium | Quickly |
| Zinc | More slowly |
| Iron | More slowly than zinc |
| Copper | Very slowly |
| Silver | Barely reacts |
| Gold | Does not react |
| Element | Calcium |
|---|---|
| Reaction with dilute acids | Very quickly |
| Element | Magnesium |
|---|---|
| Reaction with dilute acids | Quickly |
| Element | Zinc |
|---|---|
| Reaction with dilute acids | More slowly |
| Element | Iron |
|---|---|
| Reaction with dilute acids | More slowly than zinc |
| Element | Copper |
|---|---|
| Reaction with dilute acids | Very slowly |
| Element | Silver |
|---|---|
| Reaction with dilute acids | Barely reacts |
| Element | Gold |
|---|---|
| Reaction with dilute acids | Does not react |
The speed at which hydrogen bubbles are produced tells us how reactive a metal is with acid. The quicker the fizzing, the more reactive the metal.
Note that aluminium can be difficult to place in the correct position in the reactivity series during these experiments. This is because its protective aluminium oxide layer makes it appear to be less reactive than it really is. When this layer is removed, the observations are more reliable.
Non-metals in the reactivity series
It is useful to place carbon and hydrogen into the reactivity series because these elements can be used to extract metals.
Here is the reactivity series including carbon and hydrogen:
Note that zinc and iron can be displaceTake the place of another substance in a chemical reaction. For example, a metal can displace a less reactive metal from its oxide, removing oxide ions from the less reactive metal and becoming an oxide itself. from their oxideCompound containing oxygen or oxide ions. using carbon but not using hydrogen. However, copper can be extracted using carbon or hydrogen.