What is Reactivity Series? – Definition, Features & Uses

Do you know the reactivity of copper or aluminium? Do you know which element reacts with which substance?

Answers to these questions can be found easily with the help of the reactivity series, which will explain how the element’s reactivity varies to its group, atomic number, and mass. This helps you understand the reactivity series in more detail.

What is Reactivity Series?

The reactivity series is a periodic trend that explains how the reactivity of various elements decreases or increases from horizontal to vertical in the modern periodic table.

What is Reactivity Series? - Definition, Features & Uses

The first thing you have to remember is that the reactivity is only observed in metals and not in any other elements that are present in the periodic table. Furthermore, reactivity is also known as activity series, and the main reason why this phenomenon is actively found in metals is that the outer orbitals in these elements are incomplete. Thus, with very small changes, the atoms in the elements tend to lose electrons quickly. So, metals that have high atomic numbers will be more reactive and will be prone to losing electrons easily.

Reactivity Series of Metals

Element Name  Element Symbol  Reactivity of the Element 
Potassium  K  Most Reactive 
Sodium  Na  Reactivity Increases 
Calcium  Ca  Reactivity Increases 
Magnesium  Mg  Reactivity Increases 
Aluminium  Al  Reactivity Increases 
Zinc  Zn  Reactivity Increases 
Iron  Fe  Reactivity Increases 
Lead  Pb  Reactivity Decreases 
Hydrogen  He  Reactivity Decreases 
Copper  Cu  Reactivity Decreases 
Mercury  Hg  Reactivity Decreases 
Silver  Ag  Reactivity Decreases 
Gold  Au  Reactivity Decreases 
Platinum  Pt  Least Reactive 

Let’s see how different metals are more reactive than others which determines their placement on the reactivity series.

Potassium

Potassium is considered a highly reactive metal. Potassium reacts quite violently when exposed to other substances, including water or oxygen. This is why pure potassium is rather difficult to find. Instead, other substances containing potassium can be found. This high reactivity level of Potassium makes it stand on top of the reactivity series.

Sodium

Sodium ranks after potassium on the reactivity series list. Sodium is a highly reactive metal which is why it is not easily found in its pure form. Sodium loses its outer shell electron very readily. This makes it a highly reactive metal.

Calcium

In its isolated form, Calcium is considered one of the most reactive metals. When exposed to air, calcium tends to be very reactive. It immediately forms a greyish layer of nitrate and oxide. This happens because of the loss of electrons during the chemical reactions, placing calcium on top of the reactivity series.

Magnesium

Magnesium readily losses its outer shell electrons when it reacts with other substances; this is why magnesium is considered a highly reactive metal and comes on the top of the reactivity series.

Zinc

The valence shell of zinc contains two electrons and zinc readily gives up those electrons during a chemical reaction with other substances. This makes zinc relatively more reactive than other metals such as copper and hydrogen, which lose their electron quite slowly than zinc. This reactivity level of zinc makes it a part of the top one on the reactivity series.

Iron

Iron is considered an ordinarily reactive metal. In some situations, iron is highly reactive. For instance, when iron reacts with acids. Whereas in general, iron is relatively less reactive in comparison to sodium and potassium. In this way, iron comes on a rather middle area on the reactivity series.

Hydrogen

Although hydrogen has a single electron in its valence shell, it readily loses its electron during a chemical reaction with other substances. In this way, hydrogen is considered relatively more reactive in some conditions and somewhat less in others. For instance, when hydrogen is left to react with oxygen, it readily loses its valence shell electron.

Copper

Copper does not lose its electron readily upon reaction with the other compounds; hence it is not considered a highly reactive metal. Based on this relatively less reactive nature, copper is placed below some metals, including iron and hydrogen, on the list of reactivity series.

Silver

Silver is quite a less reactive metal because it tends to not lose its electron when exposed to air or water. This is why the reactivity level of silver is quite low. On the list of reactivity series, silver comes on quite a lower level because it is taken in the group of least reactive elements.

Gold

Gold is considered a least reactive metal of all. It does not react readily in any given condition, whether with oxygen, water or acid. Gold comes last on the list of reactivity series because of being the least reactive.

Reactivity of Metals with Various Substances

As a part of the metal reactivity series, certain elements only react with certain substances, while some can react with two or more substances. Here in the below section, we will list out the metals, along with their reactive substances.

Element   Ion   Reactive Substance 
Barium  Ba+  Reactive to Cold Water 
Rubidium  Rb+  Reactive to Cold Water 
Calcium  Ca+  Reactive to Cold Water 
Lithium  Li+  Reactive to Cold Water 
Caesium  Cs+  Reactive to Cold Water 
Sodium  Na+  Reactive to Cold Water 
Strontium  Sr+  Reactive to Cold Water 
Magnesium  Mg+  Slow reaction to cold water, fast reaction to hot water, vigorous reaction to acids. 
Aluminium  Al3+  Reacts with Acid and Steam 
Beryllium   Be2+  Reacts with Acid and Steam 
Titanium  Ti4+  Reactive to concentrated mineral acids 
Iron  Fe2+  Strong reaction to acids, poor reaction with steam 
Cobalt   Co2+  Strong reaction to acids, poor reaction with steam 

 

Lead  Pb2+  Strong reaction to acids, poor reaction with steam 

 

Chromium  Cr3+  Strong reaction to acids, poor reaction with steam 

 

Zinc  Zn2+  Strong reaction to acids, poor reaction with steam 

 

Manganese  Mn2+  Strong reaction to acids, poor reaction with steam 

 

Tin  Sn2+  Strong reaction to acids, poor reaction with steam 

 

Cadmium  Cd2+  Strong reaction to acids, poor reaction with steam 

 

Tungsten  W3+  The reaction is limited to a small number of strong oxidizing acids. 
Gold  Au3+  The reaction is limited to a small number of strong oxidizing acids. 

 

Mercury  Hg2+  The reaction is limited to a small number of strong oxidizing acids. 

 

Silver  Ag+  The reaction is limited to a small number of strong oxidizing acids. 

 

Copper  Cu2+  Slow reaction to water. 
Bismuth  Bi3+  The reaction is limited to a small number of strong oxidizing acids. 
Antimony  Sb3+  The reaction is limited to a small number of strong oxidizing acids. 

Features of Reactivity Series

  • Now that we have understood what reactivity series is? Let us now focus on learning the various features of the reactivity series. 
  • In present metals at the top of the reactivity series, high electro-positivity is observed, which decreases when going down the series. 
  • Along with this, the electron-donating capacity of metals down this series also decreases. 
  • Besides this, the most reactive metals in the series have the unique property of eliminating less reactive elements from their own salts. For instance, the top metals on the list can easily remove the low metals in the series from their salts.  
  • Moreover, when we go down the metal reactivity series, we can also find out that the unique property of elements that allow them to separate hydrogen from the hydrides decreases.  
  • Furthermore, when metals from the reactivity series come into contact with sulfuric acid or HCL, then they will extract hydrogen ions from these diluted solutions. 

Applications of Reactivity series

  • As you can understand from the above sections, reactivity series is a very important concept in Chemistry, and so, it has various applications, which we will talk about briefly below. 
  • Firstly, the reactivity series is actively employed in the extraction of metals.  
  • In addition to this, to displace low reactivity metals from the high metal salts, reactivity series can be used.  
  • Besides, to release the hydrogen gas from the cold water, the metals from the reactivity series can be employed.  
  • Also, to predict the reaction between the metals and acids, and their end products, using the reactivity series.  
  • Apart from this, the reactivity series also leads to a single displacement reaction, which involves the reduction of ions from the low reactive metals because of the high reactivity metals. 

Conclusion

Hope this article above helped you understand all about the metal reactivity series, most reactive elements, features of reactivity series, and applications of reactivity series. Besides, if you have any trouble understanding certain concepts of Chemistry, or any other subjects, then it would be a good idea for you to join online interactive classes offered by Tutoroot. It is budget-friendly with many benefits, check it out today. 

Frequently Asked Questions

Which is the most reactive metal?  

Potassium is the most reactive metal on the periodic table.  

What is the least reactive metal?  

As of now, noble gases are the least reactive metals.  

What is the reactivity series of metals?  

As the name itself states, reactivity series is defined as the decreasing order of reactivity in metals of the periodic table. 

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