The Reactivity Series

The reactivity series is a way of ranking elements, usually metals, according to their reactivity. This is useful because it allows us to work out which elements will displace others in compounds, and has uses in other parts of chemistry such as resistance to corrosion through the use of sacrificial metals. This post details the different reaction types that can be analysed using the reactivity series.

Chemistry - reaction types - reactivity

    High reactivity
Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Hydrogen
Copper
Silver
Gold
Low reactivity  

The reactivity series is used to predict the outcome of displacement reactions. In a displacement reaction, there is more than one element of a certain 'type' available to be in the compound. To explain what I mean by 'type', consider this:

Magnesium + copper oxide ---> Magnesium oxide + Copper

The copper is paired with the oxygen, but the magnesium could also bond with the oxygen. There are two elements competing for a place, and so the more reactive element will take that place. It does this by displacing the less reactive element.

Oxidation and reduction
Oxidation and reduction are ways of describing what has happened to an element or ion during a reaction. It is, as the name suggests, relevant to oxygen, but not exclusively.

• A substance has been oxidized if it gains oxygen. Oxidation is gain of oxygen.
•  A substance has been reduced if it loses oxygen. Reduction is loss of oxygen.
• A reducing agent is something that reduces something else.
• An oxidizing agent is something that oxidizes something else.

It can refer to the gain or loss of electrons as well. This is important to know and understand when you study the industrial chemistry topic. 

• Loss of electrons is oxidation.
• Gain of electrons is reduction

You can use the memory aid 'OIL RIG' to help you remember. Oxidation Is Loss, Reduction Is Gain. This is not to be confused with the gain or loss of oxgyen, because the gain of oxygen is oxidation, but the gain of electrons is reduction.


A REDOX reaction is one in which one element or ion is reduced, and another, different element or ion is oxidised.

Reactions of metals with water or acids uses the same rule, but instead of a metal displacing a metal it may displace hydrogen or carbon in the water or acid. Hydrogen and carbon have their places in the reactivity series too.

Reactions of metals with water -  Metals above hydrogen in the reactivity series react with water or steam to produce hydrogen.  Metals below hydrogen in the reactivity series don’t react with water or steam - they cannot displace the hydrogen.

Reactions of metals with dilute acids -  The pattern is the same as for the reaction between metals and water, except In each case the reaction is more vigorous

    We can use the reactivity series to make predictions about the results of a reaction. Given the opportunity and the right conditions, a more reactive element will always displace a less reactive one in a compound, but a less reactive one will not naturally displace a more reactive one.