Textbook: Metallurgy | Science and Technology Class 10 (Maharashtra SSC Board) PDF Download

 Page 1


93
Ø Physical properties of metals            
Ø	 Chemical properties of metals
Ø Chemical properties of nonmetals       
Ø	 Metallurgy: Various concepts.		
8. Metallurgy 
 Earth was born about 4.5 billion years ago. Various formative processes have been 
taking place in the core of the earth and its surroundings since its creation till today. These 
have resulted in the formation of various ores, liquids and gases.
Think about it
Which method do we use when we want to study many things 
together and at the same time?  
 The substances around us are in the form of some or the other elements or their 
compounds. In the beginning, elements were classified in accordance with their chemical 
and physical properties into the types metals, nonmetals and metalloids, and these are in 
use even today. You have studied their characteristics in the last standard. We are going 
to get more information about them in this lesson.
    What are the physical properties of metals and nonmetals?
Physical properties of metals
 Metals exist mainly in solid state. The metals namely, mercury and gallium exist in 
liquid state at room temperature. Metals possess luster. The metallic luster goes on 
decreasing due to exposure to atmospheric oxygen and moisture and also in presence of 
some reactive gases.
We know that metals have the properties namely, ductility and malleability. Similarly, 
all metals are good conductors of heat and electricity. Generally, all metals are hard. 
However, the alkali metals from group 1 such as lithium, sodium and potassium are 
exceptions. These metals can be cut with knife as they are very soft. Metals have high 
melting and boiling points. For example, tungsten metal has the highest melting point 
(3422 
0
C). On the contrary, the melting and boiling points of the metals  such as sodium, 
potassium, mercury, gallium are very low. A sound is produced when certain metals are 
struck. This is called  sonority. These metals are known as sonorous metals.
Physical properties of nonmetals
When properties of nonmetals are considered, it is found that some nonmetals are in 
solid state while some are in gaseous state. Exception is the nonmetal bromine which 
exists in liquid state. Nonmetals do not possess luster, but iodine is the exception as its 
crystals are shiny. Nonmetals are not hard. Diamond which as an allotrope of carbon is 
the exception. Diamond is the hardest natural substance. Nonmetals have low melting and 
boiling points. Nonmetals are bad conductors of electricity and heat. Graphite, an allotrope 
of carbon, is an exception, as it is a good conductor of electricity.
Ø 	Physical properties of nonmetals 
Ø 	Reactivity series of metals  
Ø 	Ionic compounds.
Can you tell?
Page 2


93
Ø Physical properties of metals            
Ø	 Chemical properties of metals
Ø Chemical properties of nonmetals       
Ø	 Metallurgy: Various concepts.		
8. Metallurgy 
 Earth was born about 4.5 billion years ago. Various formative processes have been 
taking place in the core of the earth and its surroundings since its creation till today. These 
have resulted in the formation of various ores, liquids and gases.
Think about it
Which method do we use when we want to study many things 
together and at the same time?  
 The substances around us are in the form of some or the other elements or their 
compounds. In the beginning, elements were classified in accordance with their chemical 
and physical properties into the types metals, nonmetals and metalloids, and these are in 
use even today. You have studied their characteristics in the last standard. We are going 
to get more information about them in this lesson.
    What are the physical properties of metals and nonmetals?
Physical properties of metals
 Metals exist mainly in solid state. The metals namely, mercury and gallium exist in 
liquid state at room temperature. Metals possess luster. The metallic luster goes on 
decreasing due to exposure to atmospheric oxygen and moisture and also in presence of 
some reactive gases.
We know that metals have the properties namely, ductility and malleability. Similarly, 
all metals are good conductors of heat and electricity. Generally, all metals are hard. 
However, the alkali metals from group 1 such as lithium, sodium and potassium are 
exceptions. These metals can be cut with knife as they are very soft. Metals have high 
melting and boiling points. For example, tungsten metal has the highest melting point 
(3422 
0
C). On the contrary, the melting and boiling points of the metals  such as sodium, 
potassium, mercury, gallium are very low. A sound is produced when certain metals are 
struck. This is called  sonority. These metals are known as sonorous metals.
Physical properties of nonmetals
When properties of nonmetals are considered, it is found that some nonmetals are in 
solid state while some are in gaseous state. Exception is the nonmetal bromine which 
exists in liquid state. Nonmetals do not possess luster, but iodine is the exception as its 
crystals are shiny. Nonmetals are not hard. Diamond which as an allotrope of carbon is 
the exception. Diamond is the hardest natural substance. Nonmetals have low melting and 
boiling points. Nonmetals are bad conductors of electricity and heat. Graphite, an allotrope 
of carbon, is an exception, as it is a good conductor of electricity.
Ø 	Physical properties of nonmetals 
Ø 	Reactivity series of metals  
Ø 	Ionic compounds.
Can you tell?
94
 Substances which are good conductors of heat 
are usually good conductors of electricity as well. 
Similarly bad conductors of heat are also bad 
conductors of electricity. The exception is diamond 
which is bad conductor of electricity but good 
conductor of heat.
Chemical properties of metals 
Apparatus : Pair of tongs or spatula, knife, burner, etc.
Chemicals : Samples of aluminium, copper, iron, 
lead, magnesium, zinc and sodium. 
(Note: Use sodium carefully, in presence of teacher)
Procedure : Hold the sample of each of the above 
metals at the top of the flame of a burner with the help 
of a pair of tongs, or a spatula.
1. Which metal catches fire readily?
2. How does the surface of a metal appear on 
catching fire?
3. What is the colour of the flame while the metal is 
burning on the flame?
Reactions of Metals: 
a. Reaction of metals with oxygen
           Metals combine with oxygen on heating in air and metal oxides are formed. Sodium 
and potassium are very reactive metals. Sodium metal combines with oxygen in the air 
even at room temperature and forms sodium oxide.
     4Na(s) + O
2
 (g)   2Na
2
O(s)
 On exposure to air sodium readily catches fire. Therefore, to prevent accident in the 
laboratory or elsewhere it is kept in kerosene. Oxides of some metals are soluble in water. 
They react with water to form alkali.
            Na
2
O (s) + H
2
O (l)  2NaOH (aq)
We know that magnesium oxide is formed on burning magnesium ribbon in the air. 
Magnesium oxide reacts with water to form an alkali, called magnesium hydroxide. 
    2Mg(s) + O
2 
(g)    2 MgO(s)
      MgO + H
2
O                        Mg(OH)
2
b. Reaction of metals with water
Apparatus : Beakers.
Chemicals : Samples of various metals (Important note : Sodium metal should not be  
   taken), water.
Procedure : Drop a piece of each of the metal in separate beakers filled with cold water.
1. Which metal reacts with water?
2. Which metal floats on water? Why? Prepare a table with reference to the above  
 procedure and note your observations in it.
Metals are reactive. They lose 
electrons easily and become 
positively charged ions. That is why  
metals are called electropositive 
elements. 
Do you know ?
Try this.
8.1 Combustion of metal 
Metal sample held 
on a spatula 
Burner
Page 3


93
Ø Physical properties of metals            
Ø	 Chemical properties of metals
Ø Chemical properties of nonmetals       
Ø	 Metallurgy: Various concepts.		
8. Metallurgy 
 Earth was born about 4.5 billion years ago. Various formative processes have been 
taking place in the core of the earth and its surroundings since its creation till today. These 
have resulted in the formation of various ores, liquids and gases.
Think about it
Which method do we use when we want to study many things 
together and at the same time?  
 The substances around us are in the form of some or the other elements or their 
compounds. In the beginning, elements were classified in accordance with their chemical 
and physical properties into the types metals, nonmetals and metalloids, and these are in 
use even today. You have studied their characteristics in the last standard. We are going 
to get more information about them in this lesson.
    What are the physical properties of metals and nonmetals?
Physical properties of metals
 Metals exist mainly in solid state. The metals namely, mercury and gallium exist in 
liquid state at room temperature. Metals possess luster. The metallic luster goes on 
decreasing due to exposure to atmospheric oxygen and moisture and also in presence of 
some reactive gases.
We know that metals have the properties namely, ductility and malleability. Similarly, 
all metals are good conductors of heat and electricity. Generally, all metals are hard. 
However, the alkali metals from group 1 such as lithium, sodium and potassium are 
exceptions. These metals can be cut with knife as they are very soft. Metals have high 
melting and boiling points. For example, tungsten metal has the highest melting point 
(3422 
0
C). On the contrary, the melting and boiling points of the metals  such as sodium, 
potassium, mercury, gallium are very low. A sound is produced when certain metals are 
struck. This is called  sonority. These metals are known as sonorous metals.
Physical properties of nonmetals
When properties of nonmetals are considered, it is found that some nonmetals are in 
solid state while some are in gaseous state. Exception is the nonmetal bromine which 
exists in liquid state. Nonmetals do not possess luster, but iodine is the exception as its 
crystals are shiny. Nonmetals are not hard. Diamond which as an allotrope of carbon is 
the exception. Diamond is the hardest natural substance. Nonmetals have low melting and 
boiling points. Nonmetals are bad conductors of electricity and heat. Graphite, an allotrope 
of carbon, is an exception, as it is a good conductor of electricity.
Ø 	Physical properties of nonmetals 
Ø 	Reactivity series of metals  
Ø 	Ionic compounds.
Can you tell?
94
 Substances which are good conductors of heat 
are usually good conductors of electricity as well. 
Similarly bad conductors of heat are also bad 
conductors of electricity. The exception is diamond 
which is bad conductor of electricity but good 
conductor of heat.
Chemical properties of metals 
Apparatus : Pair of tongs or spatula, knife, burner, etc.
Chemicals : Samples of aluminium, copper, iron, 
lead, magnesium, zinc and sodium. 
(Note: Use sodium carefully, in presence of teacher)
Procedure : Hold the sample of each of the above 
metals at the top of the flame of a burner with the help 
of a pair of tongs, or a spatula.
1. Which metal catches fire readily?
2. How does the surface of a metal appear on 
catching fire?
3. What is the colour of the flame while the metal is 
burning on the flame?
Reactions of Metals: 
a. Reaction of metals with oxygen
           Metals combine with oxygen on heating in air and metal oxides are formed. Sodium 
and potassium are very reactive metals. Sodium metal combines with oxygen in the air 
even at room temperature and forms sodium oxide.
     4Na(s) + O
2
 (g)   2Na
2
O(s)
 On exposure to air sodium readily catches fire. Therefore, to prevent accident in the 
laboratory or elsewhere it is kept in kerosene. Oxides of some metals are soluble in water. 
They react with water to form alkali.
            Na
2
O (s) + H
2
O (l)  2NaOH (aq)
We know that magnesium oxide is formed on burning magnesium ribbon in the air. 
Magnesium oxide reacts with water to form an alkali, called magnesium hydroxide. 
    2Mg(s) + O
2 
(g)    2 MgO(s)
      MgO + H
2
O                        Mg(OH)
2
b. Reaction of metals with water
Apparatus : Beakers.
Chemicals : Samples of various metals (Important note : Sodium metal should not be  
   taken), water.
Procedure : Drop a piece of each of the metal in separate beakers filled with cold water.
1. Which metal reacts with water?
2. Which metal floats on water? Why? Prepare a table with reference to the above  
 procedure and note your observations in it.
Metals are reactive. They lose 
electrons easily and become 
positively charged ions. That is why  
metals are called electropositive 
elements. 
Do you know ?
Try this.
8.1 Combustion of metal 
Metal sample held 
on a spatula 
Burner
95
 Sodium and potassium metal react rapidly and vigorously with water and liberates 
hydrogen gas.
            2Na (s) + 2H
2
O (l)   2NaOH (aq) + H
2
(g) + heat 
              2K(s) + 2H
2
O (l)     2KOH (aq) + H
2
(g) + heat
On the other hand, calcium reacts with water slowly and less vigorously. The hydrogen 
gas released in this reaction collects on the surface of the metal in the form of bubbles and 
the metal floats on water.
    2Ca(s) + 2H
2
O (l)   2Ca(OH)
2
(aq) + H
2
(g)
The metals; aluminium, iron and zinc do not react with cold or hot water, but they 
react with steam to form their oxides. Hydrogen gas is released in this reaction.
                             2Al(s) + 3H
2
O(g)   Al
2
O
3
 (s) + 3H
2
(g)
                             3Fe(s)  + 4H
2
O(g)  Fe
3
O
4
(s) + 4H
2
(g)
Try out and think about it
      Test whether the metals gold, silver and copper 
react with water and think over the finding.
   Zn(s) + H
2
O(g)                     ZnO(s) + H
2
(g)
 In the earlier chapter we 
have looked into reaction of 
metals with acids. Are all the 
metals equally reactive?
When samples of aluminium, 
magnesium, iron or zinc are 
treated with dilute sulphuric or 
hydrochloric acid, sulphate or 
chloride salts of metals are 
formed. Hydrogen gas is 
liberated in this reaction. The 
reactivity of these metals can 
be indicated by the following 
sequence.
burner  
Glass-wool soaked 
in water                    
              Metal sample
cork   
hydrogen gas 
water
hydrogen 
gas          
stand      
8.2 Reaction of a metal with water
Stand     Bubbles 
    of 
hydrogen  
gas 
Test Tube
dil HCl
Zinc 
granules 
Delivery tube 
Hydrogen 
gas burning 
with cracking 
noise
Candle  
Soap 
solution 
Soap 
bubbles 
8.3 Reaction of metals with dilute acid
c.  Reaction of metals with oxygen 
    Mg > Al > Zn > Fe 
Page 4


93
Ø Physical properties of metals            
Ø	 Chemical properties of metals
Ø Chemical properties of nonmetals       
Ø	 Metallurgy: Various concepts.		
8. Metallurgy 
 Earth was born about 4.5 billion years ago. Various formative processes have been 
taking place in the core of the earth and its surroundings since its creation till today. These 
have resulted in the formation of various ores, liquids and gases.
Think about it
Which method do we use when we want to study many things 
together and at the same time?  
 The substances around us are in the form of some or the other elements or their 
compounds. In the beginning, elements were classified in accordance with their chemical 
and physical properties into the types metals, nonmetals and metalloids, and these are in 
use even today. You have studied their characteristics in the last standard. We are going 
to get more information about them in this lesson.
    What are the physical properties of metals and nonmetals?
Physical properties of metals
 Metals exist mainly in solid state. The metals namely, mercury and gallium exist in 
liquid state at room temperature. Metals possess luster. The metallic luster goes on 
decreasing due to exposure to atmospheric oxygen and moisture and also in presence of 
some reactive gases.
We know that metals have the properties namely, ductility and malleability. Similarly, 
all metals are good conductors of heat and electricity. Generally, all metals are hard. 
However, the alkali metals from group 1 such as lithium, sodium and potassium are 
exceptions. These metals can be cut with knife as they are very soft. Metals have high 
melting and boiling points. For example, tungsten metal has the highest melting point 
(3422 
0
C). On the contrary, the melting and boiling points of the metals  such as sodium, 
potassium, mercury, gallium are very low. A sound is produced when certain metals are 
struck. This is called  sonority. These metals are known as sonorous metals.
Physical properties of nonmetals
When properties of nonmetals are considered, it is found that some nonmetals are in 
solid state while some are in gaseous state. Exception is the nonmetal bromine which 
exists in liquid state. Nonmetals do not possess luster, but iodine is the exception as its 
crystals are shiny. Nonmetals are not hard. Diamond which as an allotrope of carbon is 
the exception. Diamond is the hardest natural substance. Nonmetals have low melting and 
boiling points. Nonmetals are bad conductors of electricity and heat. Graphite, an allotrope 
of carbon, is an exception, as it is a good conductor of electricity.
Ø 	Physical properties of nonmetals 
Ø 	Reactivity series of metals  
Ø 	Ionic compounds.
Can you tell?
94
 Substances which are good conductors of heat 
are usually good conductors of electricity as well. 
Similarly bad conductors of heat are also bad 
conductors of electricity. The exception is diamond 
which is bad conductor of electricity but good 
conductor of heat.
Chemical properties of metals 
Apparatus : Pair of tongs or spatula, knife, burner, etc.
Chemicals : Samples of aluminium, copper, iron, 
lead, magnesium, zinc and sodium. 
(Note: Use sodium carefully, in presence of teacher)
Procedure : Hold the sample of each of the above 
metals at the top of the flame of a burner with the help 
of a pair of tongs, or a spatula.
1. Which metal catches fire readily?
2. How does the surface of a metal appear on 
catching fire?
3. What is the colour of the flame while the metal is 
burning on the flame?
Reactions of Metals: 
a. Reaction of metals with oxygen
           Metals combine with oxygen on heating in air and metal oxides are formed. Sodium 
and potassium are very reactive metals. Sodium metal combines with oxygen in the air 
even at room temperature and forms sodium oxide.
     4Na(s) + O
2
 (g)   2Na
2
O(s)
 On exposure to air sodium readily catches fire. Therefore, to prevent accident in the 
laboratory or elsewhere it is kept in kerosene. Oxides of some metals are soluble in water. 
They react with water to form alkali.
            Na
2
O (s) + H
2
O (l)  2NaOH (aq)
We know that magnesium oxide is formed on burning magnesium ribbon in the air. 
Magnesium oxide reacts with water to form an alkali, called magnesium hydroxide. 
    2Mg(s) + O
2 
(g)    2 MgO(s)
      MgO + H
2
O                        Mg(OH)
2
b. Reaction of metals with water
Apparatus : Beakers.
Chemicals : Samples of various metals (Important note : Sodium metal should not be  
   taken), water.
Procedure : Drop a piece of each of the metal in separate beakers filled with cold water.
1. Which metal reacts with water?
2. Which metal floats on water? Why? Prepare a table with reference to the above  
 procedure and note your observations in it.
Metals are reactive. They lose 
electrons easily and become 
positively charged ions. That is why  
metals are called electropositive 
elements. 
Do you know ?
Try this.
8.1 Combustion of metal 
Metal sample held 
on a spatula 
Burner
95
 Sodium and potassium metal react rapidly and vigorously with water and liberates 
hydrogen gas.
            2Na (s) + 2H
2
O (l)   2NaOH (aq) + H
2
(g) + heat 
              2K(s) + 2H
2
O (l)     2KOH (aq) + H
2
(g) + heat
On the other hand, calcium reacts with water slowly and less vigorously. The hydrogen 
gas released in this reaction collects on the surface of the metal in the form of bubbles and 
the metal floats on water.
    2Ca(s) + 2H
2
O (l)   2Ca(OH)
2
(aq) + H
2
(g)
The metals; aluminium, iron and zinc do not react with cold or hot water, but they 
react with steam to form their oxides. Hydrogen gas is released in this reaction.
                             2Al(s) + 3H
2
O(g)   Al
2
O
3
 (s) + 3H
2
(g)
                             3Fe(s)  + 4H
2
O(g)  Fe
3
O
4
(s) + 4H
2
(g)
Try out and think about it
      Test whether the metals gold, silver and copper 
react with water and think over the finding.
   Zn(s) + H
2
O(g)                     ZnO(s) + H
2
(g)
 In the earlier chapter we 
have looked into reaction of 
metals with acids. Are all the 
metals equally reactive?
When samples of aluminium, 
magnesium, iron or zinc are 
treated with dilute sulphuric or 
hydrochloric acid, sulphate or 
chloride salts of metals are 
formed. Hydrogen gas is 
liberated in this reaction. The 
reactivity of these metals can 
be indicated by the following 
sequence.
burner  
Glass-wool soaked 
in water                    
              Metal sample
cork   
hydrogen gas 
water
hydrogen 
gas          
stand      
8.2 Reaction of a metal with water
Stand     Bubbles 
    of 
hydrogen  
gas 
Test Tube
dil HCl
Zinc 
granules 
Delivery tube 
Hydrogen 
gas burning 
with cracking 
noise
Candle  
Soap 
solution 
Soap 
bubbles 
8.3 Reaction of metals with dilute acid
c.  Reaction of metals with oxygen 
    Mg > Al > Zn > Fe 
96
 Aqua Regia: Aqua regia is a highly corrosive and fuming liquid. It is one of the 
few reagents which can dissolve the noble metals like gold and platinum. Aqua regia 
is freshly prepared by mixing concentrated hydrochloric acid and concentrated nitric 
acid in the ratio 3:1.
      Mg(s) + 2HCl (aq)    MgCl
2
(aq) + H
2
(g)
                             2Al (s) + 6HCl (aq)  2AlCl
3
(aq) +3H
2
(g)    
                                   Fe(s) + 2HCl (aq)  FeCl
2
(aq) + H
2
(g)
                                   Zn (s) + HCl (aq)  ZnCl
2
(aq) + H
2
(g)
d. Reaction of metals with nitric acid
 Nitrate salts of metals are formed on reaction of metals with nitric acid. Various 
oxides of nitrogen (N
2
O, NO, NO
2
) are also formed in accordance with the concentration 
of nitric acid.
                    Cu(s) + 4 HNO
3
 (aq)  Cu (NO
3
)
2
 (aq) + 2NO
2
(g) + 2H
2
O (l)
                                  (Concentrated)
         3 Cu(s) + 8HNO
3
 (aq)  Cu (NO
3
)
2
 (aq) + 2NO(g) + 4H
2
O (l)
                                      (Dilute)
e. Reaction of metals with salts of other metals
Apparatus: Copper wire, iron nail, beaker or big test tube etc.
Chemicals: Aqueous solutions of ferrous sulphate and copper  
   sulphate.
Try this.
Procedure:
1. Take a clean copper wire and a 
clean iron nail.
2. Dip the copper wire in ferrous 
sulphate solution and the iron nail 
in copper sulphate solution. 
3. Keep on observing continually at 
a fixed interval of time.
a. In which test tube a reaction has 
taken place?
b. How did you recognize that a 
reaction has taken place?
c. What is the type of the reaction?
Reactivity series of metals
We have seen that reactivity of all metals is not the same. However, the reagents 
oxygen, water and acids are not useful to determine the relative reactivities of all the metals, 
as all the metals do not react with them. The displacement reaction of metals with solutions 
of salts of other metals serves this purpose. If a metal A displaces another metal B from the 
solution of its salt then it means that the metal A is more reactive than the metal B.
Copper wire
Test tube 
stand   
FeSO
4
 
solution  
CuSO
4
 
solution  
Iron nail   
Test tube                                          
Thread
Cork                                                           
8.4 Reaction of metal with solution
 of  salts of other metals
Copper coating 
formed on iron nail
Page 5


93
Ø Physical properties of metals            
Ø	 Chemical properties of metals
Ø Chemical properties of nonmetals       
Ø	 Metallurgy: Various concepts.		
8. Metallurgy 
 Earth was born about 4.5 billion years ago. Various formative processes have been 
taking place in the core of the earth and its surroundings since its creation till today. These 
have resulted in the formation of various ores, liquids and gases.
Think about it
Which method do we use when we want to study many things 
together and at the same time?  
 The substances around us are in the form of some or the other elements or their 
compounds. In the beginning, elements were classified in accordance with their chemical 
and physical properties into the types metals, nonmetals and metalloids, and these are in 
use even today. You have studied their characteristics in the last standard. We are going 
to get more information about them in this lesson.
    What are the physical properties of metals and nonmetals?
Physical properties of metals
 Metals exist mainly in solid state. The metals namely, mercury and gallium exist in 
liquid state at room temperature. Metals possess luster. The metallic luster goes on 
decreasing due to exposure to atmospheric oxygen and moisture and also in presence of 
some reactive gases.
We know that metals have the properties namely, ductility and malleability. Similarly, 
all metals are good conductors of heat and electricity. Generally, all metals are hard. 
However, the alkali metals from group 1 such as lithium, sodium and potassium are 
exceptions. These metals can be cut with knife as they are very soft. Metals have high 
melting and boiling points. For example, tungsten metal has the highest melting point 
(3422 
0
C). On the contrary, the melting and boiling points of the metals  such as sodium, 
potassium, mercury, gallium are very low. A sound is produced when certain metals are 
struck. This is called  sonority. These metals are known as sonorous metals.
Physical properties of nonmetals
When properties of nonmetals are considered, it is found that some nonmetals are in 
solid state while some are in gaseous state. Exception is the nonmetal bromine which 
exists in liquid state. Nonmetals do not possess luster, but iodine is the exception as its 
crystals are shiny. Nonmetals are not hard. Diamond which as an allotrope of carbon is 
the exception. Diamond is the hardest natural substance. Nonmetals have low melting and 
boiling points. Nonmetals are bad conductors of electricity and heat. Graphite, an allotrope 
of carbon, is an exception, as it is a good conductor of electricity.
Ø 	Physical properties of nonmetals 
Ø 	Reactivity series of metals  
Ø 	Ionic compounds.
Can you tell?
94
 Substances which are good conductors of heat 
are usually good conductors of electricity as well. 
Similarly bad conductors of heat are also bad 
conductors of electricity. The exception is diamond 
which is bad conductor of electricity but good 
conductor of heat.
Chemical properties of metals 
Apparatus : Pair of tongs or spatula, knife, burner, etc.
Chemicals : Samples of aluminium, copper, iron, 
lead, magnesium, zinc and sodium. 
(Note: Use sodium carefully, in presence of teacher)
Procedure : Hold the sample of each of the above 
metals at the top of the flame of a burner with the help 
of a pair of tongs, or a spatula.
1. Which metal catches fire readily?
2. How does the surface of a metal appear on 
catching fire?
3. What is the colour of the flame while the metal is 
burning on the flame?
Reactions of Metals: 
a. Reaction of metals with oxygen
           Metals combine with oxygen on heating in air and metal oxides are formed. Sodium 
and potassium are very reactive metals. Sodium metal combines with oxygen in the air 
even at room temperature and forms sodium oxide.
     4Na(s) + O
2
 (g)   2Na
2
O(s)
 On exposure to air sodium readily catches fire. Therefore, to prevent accident in the 
laboratory or elsewhere it is kept in kerosene. Oxides of some metals are soluble in water. 
They react with water to form alkali.
            Na
2
O (s) + H
2
O (l)  2NaOH (aq)
We know that magnesium oxide is formed on burning magnesium ribbon in the air. 
Magnesium oxide reacts with water to form an alkali, called magnesium hydroxide. 
    2Mg(s) + O
2 
(g)    2 MgO(s)
      MgO + H
2
O                        Mg(OH)
2
b. Reaction of metals with water
Apparatus : Beakers.
Chemicals : Samples of various metals (Important note : Sodium metal should not be  
   taken), water.
Procedure : Drop a piece of each of the metal in separate beakers filled with cold water.
1. Which metal reacts with water?
2. Which metal floats on water? Why? Prepare a table with reference to the above  
 procedure and note your observations in it.
Metals are reactive. They lose 
electrons easily and become 
positively charged ions. That is why  
metals are called electropositive 
elements. 
Do you know ?
Try this.
8.1 Combustion of metal 
Metal sample held 
on a spatula 
Burner
95
 Sodium and potassium metal react rapidly and vigorously with water and liberates 
hydrogen gas.
            2Na (s) + 2H
2
O (l)   2NaOH (aq) + H
2
(g) + heat 
              2K(s) + 2H
2
O (l)     2KOH (aq) + H
2
(g) + heat
On the other hand, calcium reacts with water slowly and less vigorously. The hydrogen 
gas released in this reaction collects on the surface of the metal in the form of bubbles and 
the metal floats on water.
    2Ca(s) + 2H
2
O (l)   2Ca(OH)
2
(aq) + H
2
(g)
The metals; aluminium, iron and zinc do not react with cold or hot water, but they 
react with steam to form their oxides. Hydrogen gas is released in this reaction.
                             2Al(s) + 3H
2
O(g)   Al
2
O
3
 (s) + 3H
2
(g)
                             3Fe(s)  + 4H
2
O(g)  Fe
3
O
4
(s) + 4H
2
(g)
Try out and think about it
      Test whether the metals gold, silver and copper 
react with water and think over the finding.
   Zn(s) + H
2
O(g)                     ZnO(s) + H
2
(g)
 In the earlier chapter we 
have looked into reaction of 
metals with acids. Are all the 
metals equally reactive?
When samples of aluminium, 
magnesium, iron or zinc are 
treated with dilute sulphuric or 
hydrochloric acid, sulphate or 
chloride salts of metals are 
formed. Hydrogen gas is 
liberated in this reaction. The 
reactivity of these metals can 
be indicated by the following 
sequence.
burner  
Glass-wool soaked 
in water                    
              Metal sample
cork   
hydrogen gas 
water
hydrogen 
gas          
stand      
8.2 Reaction of a metal with water
Stand     Bubbles 
    of 
hydrogen  
gas 
Test Tube
dil HCl
Zinc 
granules 
Delivery tube 
Hydrogen 
gas burning 
with cracking 
noise
Candle  
Soap 
solution 
Soap 
bubbles 
8.3 Reaction of metals with dilute acid
c.  Reaction of metals with oxygen 
    Mg > Al > Zn > Fe 
96
 Aqua Regia: Aqua regia is a highly corrosive and fuming liquid. It is one of the 
few reagents which can dissolve the noble metals like gold and platinum. Aqua regia 
is freshly prepared by mixing concentrated hydrochloric acid and concentrated nitric 
acid in the ratio 3:1.
      Mg(s) + 2HCl (aq)    MgCl
2
(aq) + H
2
(g)
                             2Al (s) + 6HCl (aq)  2AlCl
3
(aq) +3H
2
(g)    
                                   Fe(s) + 2HCl (aq)  FeCl
2
(aq) + H
2
(g)
                                   Zn (s) + HCl (aq)  ZnCl
2
(aq) + H
2
(g)
d. Reaction of metals with nitric acid
 Nitrate salts of metals are formed on reaction of metals with nitric acid. Various 
oxides of nitrogen (N
2
O, NO, NO
2
) are also formed in accordance with the concentration 
of nitric acid.
                    Cu(s) + 4 HNO
3
 (aq)  Cu (NO
3
)
2
 (aq) + 2NO
2
(g) + 2H
2
O (l)
                                  (Concentrated)
         3 Cu(s) + 8HNO
3
 (aq)  Cu (NO
3
)
2
 (aq) + 2NO(g) + 4H
2
O (l)
                                      (Dilute)
e. Reaction of metals with salts of other metals
Apparatus: Copper wire, iron nail, beaker or big test tube etc.
Chemicals: Aqueous solutions of ferrous sulphate and copper  
   sulphate.
Try this.
Procedure:
1. Take a clean copper wire and a 
clean iron nail.
2. Dip the copper wire in ferrous 
sulphate solution and the iron nail 
in copper sulphate solution. 
3. Keep on observing continually at 
a fixed interval of time.
a. In which test tube a reaction has 
taken place?
b. How did you recognize that a 
reaction has taken place?
c. What is the type of the reaction?
Reactivity series of metals
We have seen that reactivity of all metals is not the same. However, the reagents 
oxygen, water and acids are not useful to determine the relative reactivities of all the metals, 
as all the metals do not react with them. The displacement reaction of metals with solutions 
of salts of other metals serves this purpose. If a metal A displaces another metal B from the 
solution of its salt then it means that the metal A is more reactive than the metal B.
Copper wire
Test tube 
stand   
FeSO
4
 
solution  
CuSO
4
 
solution  
Iron nail   
Test tube                                          
Thread
Cork                                                           
8.4 Reaction of metal with solution
 of  salts of other metals
Copper coating 
formed on iron nail
97
Metal A + Salt solution of metal B   Salt solution of metal A + Metal B
Answer from your observations in the previous activity 8.4, which metal is more 
reactive, copper or iron?
In the previous activity, iron has displaced copper from copper sulphate. It means that 
metallic iron is more reactive than metallic copper.
 Scientists have developed the 
reactivity series by doing many 
experiments of displacement 
reaction. The arrangement of 
metals in the increasing or 
decreasing order of reactivity is 
called the reactivity series of 
metals. Metals are divided into 
the following groups according to 
their reactivity.
1. Highly reactive metals.
2. Moderately reactive metals.
3. Less reactive metals.
f. Reaction of metals with nonmetals
Noble gases (like helium, neon, argon) do not take part in the chemical reactions. So 
far, we have seen from the reactions of metals that cations are formed by oxidation of 
metals. If we look into the electronic configuration of some metals and nonmetals, it will 
be seen that the driving force behind a reaction is to attain the electronic configuration of 
the nearest noble gas with complete octet. Metals do this by losing electrons while 
nonmetals do this by gaining electrons. The outermost shell of noble gases being complete, 
they are chemically inert.
You have seen in the last standard that the ionic compound sodium chloride is formed 
as sodium metal gives away one electron while the nonmetal chlorine takes up one electron.
2 Na   +   Cl
2
                     2 NaCl
      Similarly, magnesium and potassium form 
the ionic  compounds MgCl
2
  and KCl, respectively.       Chemical properties of nonmetals
Nonmetals are a collection of elements having less similarity in physical and chemical 
properties. Nonmetals are also called electronegative elements, as they form negatively 
charged ions by accepting electron. Some examples  of chemical reactions of nonmetals 
are as follows.
1.Reaction of nonmetals with oxygen:
 Generally, nonmetals combine with 
oxygen to form acidic oxides.
In some cases, neutral oxides are formed.
8.5 Reactivity series of metals.
Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
Zinc
Iron
Tin
Lead
Copper
Mercury
Silver
Gold
(Metal) (nonmetal) (ionic compound)
 C + O
2     
  CO
2 
(Acidic)
 2C + O
2      
2CO(Neutral)
 S + O
2      
  SO
2 
(Acidic)
Complete combustion          
Partial Combustion 
Combustion 
React with acids
React with oxygen
React with water Higher
Reactivity
Lower