The reactivity series is a ranking chart that informs us how active some metals are compared to others. The reactivity series assists scientists and students in predicting the results of chemical reactions, knowing which metals are able to displace others from salt solutions, and selecting appropriate methods for retrieving metals from ores. Let’s learn about it in detail.
The Reactivity Series is an ordered list of elements, primarily metals, in order of their chemical reactivity. This indicates that the most reactive metal comes first at the top, followed by the least reactive one at the bottom. A metal's reactivity is determined by the ease with which it can lose electrons to become positive ions (cations). Potassium and sodium are highly reactive metals which lose electrons readily and vigorously react with water and acids. Copper, silver, and gold are less reactive metals that are stable and do not react or do so very weakly.
Here's the entire Reactivity Series of metals, ranking from most reactive to least reactive:
Note: Hydrogen is not a metal but is listed to compare how metals respond to acids.
* Metals higher than hydrogen on the list react with acids to form hydrogen gas.
* Metals lower than hydrogen do not push out hydrogen from acids.
Example:
Zinc (Zn) is higher than hydrogen. Therefore, it reacts with hydrochloric acid:
Zn + 2HCl → ZnCl₂ + H₂↑
But Copper (Cu) doesn't react with hydrochloric acid, as it comes below hydrogen in the series.
Whereas metals lose electrons, non-metals gain electrons in reactions. Although there is no specific reactivity series for non-metals, we can still make some sort of arrangement for common non-metals according to their reactivity.
Here's a rough order of the reactivity series of non-metals:
Fluorine is the most reactive of the non-metals. It reacts violently with nearly all elements. On the contrary, carbon and hydrogen are less reactive.
This order enables us to comprehend:
* Displacement reactions among halogens.
* Combustion and oxidation reactions.
* Which non-metal will predominate in a redox reaction?
Example:
Chlorine will displace bromine from its compound:
Cl₂ + 2KBr → 2KCl + Br₂
Because chlorine is higher in the reactivity series of non-metals.
To remember the reactivity series of metals for class 10 in a snap, students can adopt this playful mnemonic:
Please Stop Calling Me A Zebra, I Like Her Call Smart Girl Pretty
Each word stands for a metal:
This easy sentence assists students in memorising the order without tension.
The reactivity series tricks are more than just a chemistry subject. It has practical applications in science and other aspects of life. Let's discuss how this information assists us in daily life and science.
a) Predicting Reactions
The reactivity series informs us which metal will react and to what extent. Sodium and potassium, for instance, react with cold water, whereas iron only reacts with steam.
Example:
Sodium reacts with water:
2Na + 2H₂O → 2NaOH + H₂↑
But copper won't react with water at all.
b) Displacement Reactions
A more reactive metal can displace a less reactive metal from its salt solution.
Example:
Zinc is more reactive and thus displaces copper from copper sulfate:
Zn + CuSO₄ → ZnSO₄ + Cu
This principle is applied in most chemical industries.
c) Metal Extraction
The reactivity series assists in selecting the appropriate process to extract metals from their ores.
* Very reactive metals (such as aluminium) are obtained by electrolysis.
* Less reactive metals (such as iron) can be obtained by carbon reduction.
d) Preventing Corrosion
Metals low in the series, such as gold and platinum, do not react and are corrosion resistant. That is why they are used to make jewellery.
For other metals, their reactivity informs us how to coat them or paint them in order to protect them.
e) Storage of Reactive Metals
Metals such as sodium and potassium react rapidly with air and water. So they are stored under oil to avoid unsafe reactions.
(Session 2025 - 26)