Class 7 Science Chapter 4 NCERT Book - The World of Metals and Non-metals

 Page 1


Yashwant and Anandi live in a village in Rajasthan. Their school 
has assigned them a project to learn about craftspersons who 
work with metals. They decide to visit the local ironsmiths who 
practise this craft. Yashwant and Anandi request their grandfather 
to accompany them (Fig. 4.1). They are curious to learn how these 
ironsmiths make di? erent items of daily use. They interact with 
an elderly craftsperson, Sudarshan uncle. 
Yashwant: Which items do you generally make?
Sudarshan: Generally, we make items of daily use, such as ? at 
pans (tawas), buckets (baltis), tongs (chimtas), and farming tools 
like spades (phawras), axes (kulhadis), trowels (khurpis), and 
rakes (jelees). 
Anandi: What materials are they made of?
 Fig. 4.1: Ironsmith making various items
The World of Metals 
and Non-metals
4
Chapter 4.indd   41 4/3/2025   4:52:08 PM
Page 2


Yashwant and Anandi live in a village in Rajasthan. Their school 
has assigned them a project to learn about craftspersons who 
work with metals. They decide to visit the local ironsmiths who 
practise this craft. Yashwant and Anandi request their grandfather 
to accompany them (Fig. 4.1). They are curious to learn how these 
ironsmiths make di? erent items of daily use. They interact with 
an elderly craftsperson, Sudarshan uncle. 
Yashwant: Which items do you generally make?
Sudarshan: Generally, we make items of daily use, such as ? at 
pans (tawas), buckets (baltis), tongs (chimtas), and farming tools 
like spades (phawras), axes (kulhadis), trowels (khurpis), and 
rakes (jelees). 
Anandi: What materials are they made of?
 Fig. 4.1: Ironsmith making various items
The World of Metals 
and Non-metals
4
Chapter 4.indd   41 4/3/2025   4:52:08 PM
Curiosity | Textbook of Science | Grade 7
42
Sudarshan: We use iron metal to make these items. We also use 
wood to prepare handles wherever required. Additionally, we 
use coal in our furnaces to heat the iron.
Sudarshan is heating an iron block in the furnace. It has become 
red hot. He starts beating it hard with a hammer.
Anandi is amazed and asks, “Why are you beating it?” 
Sudarshan: I am beating it to shape it into an axe.
Anandi: Wow, a piece of iron can be beaten into a ? at shape! Can 
we do this with other metals as well?
You may also have many such questions?—?let us explore what 
else we can do with metals.
4.1 Properties of Materials
4.1.1 Malleability
Activity 4.1: Let us explore
Caution—?Conduct this activity under the supervision of your teacher 
or an adult.
? Collect some waste pieces of copper and aluminium, an iron 
nail, a piece of coal, a pea-sized lump of sulfur (gandhak), 
and a block of wood.
? Recall the chapter ‘Materials Around Us’ in the Grade 6 
Science textbook Curiosity and observe the appearances of 
the above items. Are they lustrous? Also, note whether they 
are hard or soft and record  your observations in Table 4.1.
Fig. 4.2: Beating an iron nail with a hammer
? Now, place each of these 
items one by one on any 
hard surface and beat them 
with a hammer (Fig. 4.2). 
? What do you think will 
happen? Do the objects 
become slightly ? attened or 
do they break into pieces? 
? Record your observations in 
Table 4.1.
Chapter 4.indd   42 4/3/2025   4:52:08 PM
Page 3


Yashwant and Anandi live in a village in Rajasthan. Their school 
has assigned them a project to learn about craftspersons who 
work with metals. They decide to visit the local ironsmiths who 
practise this craft. Yashwant and Anandi request their grandfather 
to accompany them (Fig. 4.1). They are curious to learn how these 
ironsmiths make di? erent items of daily use. They interact with 
an elderly craftsperson, Sudarshan uncle. 
Yashwant: Which items do you generally make?
Sudarshan: Generally, we make items of daily use, such as ? at 
pans (tawas), buckets (baltis), tongs (chimtas), and farming tools 
like spades (phawras), axes (kulhadis), trowels (khurpis), and 
rakes (jelees). 
Anandi: What materials are they made of?
 Fig. 4.1: Ironsmith making various items
The World of Metals 
and Non-metals
4
Chapter 4.indd   41 4/3/2025   4:52:08 PM
Curiosity | Textbook of Science | Grade 7
42
Sudarshan: We use iron metal to make these items. We also use 
wood to prepare handles wherever required. Additionally, we 
use coal in our furnaces to heat the iron.
Sudarshan is heating an iron block in the furnace. It has become 
red hot. He starts beating it hard with a hammer.
Anandi is amazed and asks, “Why are you beating it?” 
Sudarshan: I am beating it to shape it into an axe.
Anandi: Wow, a piece of iron can be beaten into a ? at shape! Can 
we do this with other metals as well?
You may also have many such questions?—?let us explore what 
else we can do with metals.
4.1 Properties of Materials
4.1.1 Malleability
Activity 4.1: Let us explore
Caution—?Conduct this activity under the supervision of your teacher 
or an adult.
? Collect some waste pieces of copper and aluminium, an iron 
nail, a piece of coal, a pea-sized lump of sulfur (gandhak), 
and a block of wood.
? Recall the chapter ‘Materials Around Us’ in the Grade 6 
Science textbook Curiosity and observe the appearances of 
the above items. Are they lustrous? Also, note whether they 
are hard or soft and record  your observations in Table 4.1.
Fig. 4.2: Beating an iron nail with a hammer
? Now, place each of these 
items one by one on any 
hard surface and beat them 
with a hammer (Fig. 4.2). 
? What do you think will 
happen? Do the objects 
become slightly ? attened or 
do they break into pieces? 
? Record your observations in 
Table 4.1.
Chapter 4.indd   42 4/3/2025   4:52:08 PM
The World of Metals and Non-metals
43
Appearance
(lustrous/ 
non-lustrous)
Effect of hammering 
(? attens/breaks into 
pieces)
Piece of copper 1.
2.
3.
4.
5.
6.
Piece of aluminium
Iron nail
Lump of sulfur 
(pea-sized)
Piece of coal
Block of wood
Object/Material
S.No.
Hard/Soft
Table 4.1: Appearance, hardness, and e? ect of hammering on di? erent 
objects or materials
Analyse Table 4.1. Identify the objects that are lustrous in 
appearance and hard. You might have observed that objects made 
from copper, aluminium, and iron are lustrous in appearance 
and are hard. Lustre shown by metals is known as metallic 
lustre. Materials like copper, aluminium, and iron are known as 
metals, whereas, coal, sulfur, and wood are non-lustrous and 
not as hard as metals. 
Are all metals hard and solid? Not really; some metals like 
sodium and potassium are so soft that they can be cut with a 
knife. There is one metal, mercury , that is found in a liquid state at 
room temperature, which you might have seen in thermometers. 
Recall the chapter ‘Temperature and its Measurement’ from the 
Grade 6 Science textbook Curiosity. 
Which objects did you ? nd become ? at on beating with a 
hammer?
You must have observed that objects such as a piece of copper , 
an iron nail, and a piece of aluminium become ? at when beaten; 
whereas other objects or materials behave di? erently. This 
property by which materials can be beaten into thin sheets is 
called malleability. Most metals possess this property. Can you 
give some examples of metal sheets? You might have seen thin 
silver foil on some sweets and aluminium foil used for wrapping 
food items. These are formed due to their malleability. Gold and 
silver are the most malleable metals. 
Chapter 4.indd   43 4/3/2025   4:52:08 PM
Page 4


Yashwant and Anandi live in a village in Rajasthan. Their school 
has assigned them a project to learn about craftspersons who 
work with metals. They decide to visit the local ironsmiths who 
practise this craft. Yashwant and Anandi request their grandfather 
to accompany them (Fig. 4.1). They are curious to learn how these 
ironsmiths make di? erent items of daily use. They interact with 
an elderly craftsperson, Sudarshan uncle. 
Yashwant: Which items do you generally make?
Sudarshan: Generally, we make items of daily use, such as ? at 
pans (tawas), buckets (baltis), tongs (chimtas), and farming tools 
like spades (phawras), axes (kulhadis), trowels (khurpis), and 
rakes (jelees). 
Anandi: What materials are they made of?
 Fig. 4.1: Ironsmith making various items
The World of Metals 
and Non-metals
4
Chapter 4.indd   41 4/3/2025   4:52:08 PM
Curiosity | Textbook of Science | Grade 7
42
Sudarshan: We use iron metal to make these items. We also use 
wood to prepare handles wherever required. Additionally, we 
use coal in our furnaces to heat the iron.
Sudarshan is heating an iron block in the furnace. It has become 
red hot. He starts beating it hard with a hammer.
Anandi is amazed and asks, “Why are you beating it?” 
Sudarshan: I am beating it to shape it into an axe.
Anandi: Wow, a piece of iron can be beaten into a ? at shape! Can 
we do this with other metals as well?
You may also have many such questions?—?let us explore what 
else we can do with metals.
4.1 Properties of Materials
4.1.1 Malleability
Activity 4.1: Let us explore
Caution—?Conduct this activity under the supervision of your teacher 
or an adult.
? Collect some waste pieces of copper and aluminium, an iron 
nail, a piece of coal, a pea-sized lump of sulfur (gandhak), 
and a block of wood.
? Recall the chapter ‘Materials Around Us’ in the Grade 6 
Science textbook Curiosity and observe the appearances of 
the above items. Are they lustrous? Also, note whether they 
are hard or soft and record  your observations in Table 4.1.
Fig. 4.2: Beating an iron nail with a hammer
? Now, place each of these 
items one by one on any 
hard surface and beat them 
with a hammer (Fig. 4.2). 
? What do you think will 
happen? Do the objects 
become slightly ? attened or 
do they break into pieces? 
? Record your observations in 
Table 4.1.
Chapter 4.indd   42 4/3/2025   4:52:08 PM
The World of Metals and Non-metals
43
Appearance
(lustrous/ 
non-lustrous)
Effect of hammering 
(? attens/breaks into 
pieces)
Piece of copper 1.
2.
3.
4.
5.
6.
Piece of aluminium
Iron nail
Lump of sulfur 
(pea-sized)
Piece of coal
Block of wood
Object/Material
S.No.
Hard/Soft
Table 4.1: Appearance, hardness, and e? ect of hammering on di? erent 
objects or materials
Analyse Table 4.1. Identify the objects that are lustrous in 
appearance and hard. You might have observed that objects made 
from copper, aluminium, and iron are lustrous in appearance 
and are hard. Lustre shown by metals is known as metallic 
lustre. Materials like copper, aluminium, and iron are known as 
metals, whereas, coal, sulfur, and wood are non-lustrous and 
not as hard as metals. 
Are all metals hard and solid? Not really; some metals like 
sodium and potassium are so soft that they can be cut with a 
knife. There is one metal, mercury , that is found in a liquid state at 
room temperature, which you might have seen in thermometers. 
Recall the chapter ‘Temperature and its Measurement’ from the 
Grade 6 Science textbook Curiosity. 
Which objects did you ? nd become ? at on beating with a 
hammer?
You must have observed that objects such as a piece of copper , 
an iron nail, and a piece of aluminium become ? at when beaten; 
whereas other objects or materials behave di? erently. This 
property by which materials can be beaten into thin sheets is 
called malleability. Most metals possess this property. Can you 
give some examples of metal sheets? You might have seen thin 
silver foil on some sweets and aluminium foil used for wrapping 
food items. These are formed due to their malleability. Gold and 
silver are the most malleable metals. 
Chapter 4.indd   43 4/3/2025   4:52:08 PM
Curiosity | Textbook of Science | Grade 7
44
A piece of coal or a lump of sulfur does not show this behaviour . 
They break into pieces and are said to be brittle. On the other 
hand, wood neither gets ? attened into a sheet nor breaks into 
pieces. Therefore, wood is neither malleable nor brittle. 
HOLISTIC LENS
The impact of iron on the progress of civilisation of India
In the Grade 6 Social Science textbook Exploring Society India and 
Beyond, you learnt about the Harappans. They knew how to use 
metals like copper and gold. They used these metals to make various 
objects, from utensils to jewellery. However, you would hardly ? nd 
any evidence of the Harappans using a very prominent metal iron, 
which you see a lot around you today. This is because it took a long 
time before iron was used in day-to-day activities.
 However, once the use of iron gained prominence in the times that 
followed, it contributed signi? cantly to the progress of civilisation in 
India. For instance, due to its strength, agricultural tools like ploughs 
made from iron were much superior to those used previously. 
 What could be the potential reason that it is generally considered 
that copper was discovered earlier as compared to iron?
which you see a lot around you today. This is because it took a long 
time before iron was used in day-to-day activities.
 However, once the use of iron gained prominence in the times that 
followed, it contributed signi? cantly to the progress of civilisation in 
India. For instance, due to its strength, agricultural tools like ploughs 
made from iron were much superior to those used previously. 
 What could be the potential reason that it is generally considered 
that copper was discovered earlier as compared to iron?
4.1.2 Ductility
Where do you ? nd the use of metal wires? 
You might have seen wires of metals like copper or aluminium 
in electrical ? ttings. Some ornaments, like bangles, necklaces, 
earrings, etc., are also made from metal wires. Metal wires play 
important functions in a variety of stringed musical instruments, 
such as veena, sitar, violin, and guitar.
This property of materials by which they can be drawn into 
wires is called ductility.
This property of ductility is mainly possessed by metals.
Gold is so ductile 
that one gram of it 
can be drawn into a 
2 kilometre-long wire! 
The ductile nature of 
metals enables for 
the creation of 
this tea strainer 
with metal wire.
Chapter 4.indd   44 4/3/2025   4:52:11 PM
Page 5


Yashwant and Anandi live in a village in Rajasthan. Their school 
has assigned them a project to learn about craftspersons who 
work with metals. They decide to visit the local ironsmiths who 
practise this craft. Yashwant and Anandi request their grandfather 
to accompany them (Fig. 4.1). They are curious to learn how these 
ironsmiths make di? erent items of daily use. They interact with 
an elderly craftsperson, Sudarshan uncle. 
Yashwant: Which items do you generally make?
Sudarshan: Generally, we make items of daily use, such as ? at 
pans (tawas), buckets (baltis), tongs (chimtas), and farming tools 
like spades (phawras), axes (kulhadis), trowels (khurpis), and 
rakes (jelees). 
Anandi: What materials are they made of?
 Fig. 4.1: Ironsmith making various items
The World of Metals 
and Non-metals
4
Chapter 4.indd   41 4/3/2025   4:52:08 PM
Curiosity | Textbook of Science | Grade 7
42
Sudarshan: We use iron metal to make these items. We also use 
wood to prepare handles wherever required. Additionally, we 
use coal in our furnaces to heat the iron.
Sudarshan is heating an iron block in the furnace. It has become 
red hot. He starts beating it hard with a hammer.
Anandi is amazed and asks, “Why are you beating it?” 
Sudarshan: I am beating it to shape it into an axe.
Anandi: Wow, a piece of iron can be beaten into a ? at shape! Can 
we do this with other metals as well?
You may also have many such questions?—?let us explore what 
else we can do with metals.
4.1 Properties of Materials
4.1.1 Malleability
Activity 4.1: Let us explore
Caution—?Conduct this activity under the supervision of your teacher 
or an adult.
? Collect some waste pieces of copper and aluminium, an iron 
nail, a piece of coal, a pea-sized lump of sulfur (gandhak), 
and a block of wood.
? Recall the chapter ‘Materials Around Us’ in the Grade 6 
Science textbook Curiosity and observe the appearances of 
the above items. Are they lustrous? Also, note whether they 
are hard or soft and record  your observations in Table 4.1.
Fig. 4.2: Beating an iron nail with a hammer
? Now, place each of these 
items one by one on any 
hard surface and beat them 
with a hammer (Fig. 4.2). 
? What do you think will 
happen? Do the objects 
become slightly ? attened or 
do they break into pieces? 
? Record your observations in 
Table 4.1.
Chapter 4.indd   42 4/3/2025   4:52:08 PM
The World of Metals and Non-metals
43
Appearance
(lustrous/ 
non-lustrous)
Effect of hammering 
(? attens/breaks into 
pieces)
Piece of copper 1.
2.
3.
4.
5.
6.
Piece of aluminium
Iron nail
Lump of sulfur 
(pea-sized)
Piece of coal
Block of wood
Object/Material
S.No.
Hard/Soft
Table 4.1: Appearance, hardness, and e? ect of hammering on di? erent 
objects or materials
Analyse Table 4.1. Identify the objects that are lustrous in 
appearance and hard. You might have observed that objects made 
from copper, aluminium, and iron are lustrous in appearance 
and are hard. Lustre shown by metals is known as metallic 
lustre. Materials like copper, aluminium, and iron are known as 
metals, whereas, coal, sulfur, and wood are non-lustrous and 
not as hard as metals. 
Are all metals hard and solid? Not really; some metals like 
sodium and potassium are so soft that they can be cut with a 
knife. There is one metal, mercury , that is found in a liquid state at 
room temperature, which you might have seen in thermometers. 
Recall the chapter ‘Temperature and its Measurement’ from the 
Grade 6 Science textbook Curiosity. 
Which objects did you ? nd become ? at on beating with a 
hammer?
You must have observed that objects such as a piece of copper , 
an iron nail, and a piece of aluminium become ? at when beaten; 
whereas other objects or materials behave di? erently. This 
property by which materials can be beaten into thin sheets is 
called malleability. Most metals possess this property. Can you 
give some examples of metal sheets? You might have seen thin 
silver foil on some sweets and aluminium foil used for wrapping 
food items. These are formed due to their malleability. Gold and 
silver are the most malleable metals. 
Chapter 4.indd   43 4/3/2025   4:52:08 PM
Curiosity | Textbook of Science | Grade 7
44
A piece of coal or a lump of sulfur does not show this behaviour . 
They break into pieces and are said to be brittle. On the other 
hand, wood neither gets ? attened into a sheet nor breaks into 
pieces. Therefore, wood is neither malleable nor brittle. 
HOLISTIC LENS
The impact of iron on the progress of civilisation of India
In the Grade 6 Social Science textbook Exploring Society India and 
Beyond, you learnt about the Harappans. They knew how to use 
metals like copper and gold. They used these metals to make various 
objects, from utensils to jewellery. However, you would hardly ? nd 
any evidence of the Harappans using a very prominent metal iron, 
which you see a lot around you today. This is because it took a long 
time before iron was used in day-to-day activities.
 However, once the use of iron gained prominence in the times that 
followed, it contributed signi? cantly to the progress of civilisation in 
India. For instance, due to its strength, agricultural tools like ploughs 
made from iron were much superior to those used previously. 
 What could be the potential reason that it is generally considered 
that copper was discovered earlier as compared to iron?
which you see a lot around you today. This is because it took a long 
time before iron was used in day-to-day activities.
 However, once the use of iron gained prominence in the times that 
followed, it contributed signi? cantly to the progress of civilisation in 
India. For instance, due to its strength, agricultural tools like ploughs 
made from iron were much superior to those used previously. 
 What could be the potential reason that it is generally considered 
that copper was discovered earlier as compared to iron?
4.1.2 Ductility
Where do you ? nd the use of metal wires? 
You might have seen wires of metals like copper or aluminium 
in electrical ? ttings. Some ornaments, like bangles, necklaces, 
earrings, etc., are also made from metal wires. Metal wires play 
important functions in a variety of stringed musical instruments, 
such as veena, sitar, violin, and guitar.
This property of materials by which they can be drawn into 
wires is called ductility.
This property of ductility is mainly possessed by metals.
Gold is so ductile 
that one gram of it 
can be drawn into a 
2 kilometre-long wire! 
The ductile nature of 
metals enables for 
the creation of 
this tea strainer 
with metal wire.
Chapter 4.indd   44 4/3/2025   4:52:11 PM
The World of Metals and Non-metals
45
Have you ever seen wires made of coal or sulfur? Obviously 
not! We can say that coal and sulfur are not ductile.
Do you know that ropes made of steel [a mixture 
of metal (iron) and non-metal (carbon)] wires can 
support heavy loads? Therefore, they are used in 
suspension bridges and in cranes to lift heavy objects.
D
IVE
EEPER
Suspension bridge
4.1.3 Sonority
Have you ever noticed the sound produced when a metal spoon, 
or a metal plate, or a metal coin is dropped on the ? oor? How is it 
di? erent from the sound produced when a piece of coal or wood 
is dropped on the ? oor?  
Activity 4.2: Let us investigate
Caution—?Be careful while dropping the 
objects.
? Take a few objects, such as a metal 
spoon, a coin, a piece of coal, and 
a block of wood. 
? Drop them one by one from a certain height.
? Do you notice any di? erence in the sound 
produced by these objects? 
I use the di? erence in 
sound when my stick 
hits wood or metal to 
help ? nd my way.
Chapter 4.indd   45 4/3/2025   4:52:13 PM