Reactivity Series

What is a reactivity series?

Reactivity series is the series of metals based on their reactivity from highest to lowest. So, reactivity series of metals can be defined as a series of metals, in order of reactivity from highest to lowest. It is also known as activity series. The reactivity of metals is because of their incomplete outer orbitals or due to their electronic configuration. Metals form positively charged ions as they tend to lose electrons. Metals with high atomic numbers tend to be more reactive as their electrons are far from the positively charged nucleus. So, they can be removed easily. 

Reactivity series of metals is given below - 

Symbol of element 

Name of element 


Potassium 


Most Reactive 

Na 

Sodium 






↓Reactivity decreases


Ca

Calcium 

Mg 

Magnesium 

Al 

Aluminium 

Zn 

Zinc 

Fe 

Iron 

Pb 

Lead 

Hydrogen 

Cu

Copper 

Hg

Mercury 

Ag 

Silver 

Au 

Gold 

Pt 

Platinum 

Least reactive 


Metals from potassium to calcium are highly reactive and even react with water. While metals from magnesium to lead can react with acids. Metals from copper to platinum are highly unreactive and don’t react with any other substance in normal conditions. This is the reason why platinum and gold don’t get corrode easily and don’t form oxides. While metals such as zinc, aluminum, magnesium, calcium etc. form oxides readily. 

Hydrogen is a non-metal but still it has been included in the reactivity series as it helps in the comparison of reactivity of metals. 

Salient Features 

  • Metals present at the top of reactivity series are highly electropositive metals. The electropositive character of metals decreases as we go down the series. 

  • Reducing power of metals decreases as we go down the series. Thus, potassium is the strongest reducing agent. 

  • As we go down the reactivity series, the ability of metals to remove hydrogen from hydrides decreases. 

  • Metals present in the reactivity series above hydrogen can remove hydrogen ions from dilute HCl or Dilute sulphuric acid. 

  • The metal which is more reactive than other metal can remove less reactive metal from its salt. Thus, metals placed at the top of the reactivity series can remove the metals which are present at the bottom of the series from their salts. 

  • The metals which are placed above in the series can be extracted by electrolysis. While metals from Zinc to Hg can be extracted by simply reducing their oxides, which is an inexpensive method.  

  • When we move down the series the electron-donating capacity of metals decreases. 

Important uses of reactivity series – 

  • In displacement reaction – Displacement reactions are those reactions in which more reactive metal displaces less reactive metal from its salt. So, by reactivity series you can tell which metal will displace another metal. 

  • Reaction between metals and water – Metals from potassium to calcium can react with cold water and release hydrogen gas. 

  • Reaction between metals and acids – Lead and other metals which are more reactive than lead in the reactivity series can react with hydrochloric acid and sulphuric acid and form salts. Thus, we can predict the reactions by reactivity series. 

 Short trick to remember reactivity series – 

Please send charlie’s monkeys and zebras in lead & hydrogen cages in mountains   securely guarded by plato. 

In the above given sentence, each bold alphabet denotes the elements of reactivity series in order of their reactivity from highest to lowest. You can understand this better by the table given below - 

Elements of reactivity series 

Sentence to remember the series 

K (Potassium)

Please 

Na (Sodium)

Send 

Ca (Calcium)

Charlie’s 

Mg (Magnesium)

Monkey 

Al (Aluminum)

And 

Zn (Zinc)

Zebra 

Fe (Iron)

In 

Pb (Lead)

Lead &

H (Hydrogen)

Hydrogen 

Cu (Copper)

Cages 

Hg (Mercury)

in Mountains 

Ag (Silver)

Securely 

Au (Gold)

Guarded by

Pt (Platinum)

Plato