Chapter 4: The World of Metals and Non-metals Class 8th Science (Curiosity) NCERT Solution

July 13, 2026 • Admin ETeam • Class 7, Class 7 NCERT Solution

Class 7 Science Chapter 4 – The World of Metals and Non-metals | Solutions

Curiosity • Textbook of Science • Grade 7

Chapter 4 — The World of Metals and Non-metals

All activities, tables, in-text questions and the full “Let Us Enhance Our Learning” exercise — solved with the textbook’s own figures.

In-Text Questions, Activities & Tables

An ironsmith making various items of daily use — Fig. 4.1 — Ironsmith making various items (from the chapter)

Anandi: What materials are the items made of? And why is Sudarshan beating the red-hot iron block? Can other metals also be beaten flat?

SOLUTION

Materials used: iron for the items (tawa, balti, chimta, phawra, kulhadi, khurpi, jelee), wood for the handles, and coal in the furnace to heat the iron.
Why beating? Sudarshan beats the hot iron to shape it into an axe. Iron can be beaten into a flat shape without breaking.
Yes, other metals can also be beaten into sheets — this property is called malleability, and it is the first property explored in this chapter.

4.1.1 Malleability — Activity 4.1 & Table 4.1

A4.1

Observe the appearance and hardness of copper, aluminium, an iron nail, coal, sulfur and wood. Then beat each with a hammer. Do they flatten or break? Complete Table 4.1.

SOLUTION — TABLE 4.1 (COMPLETED)

Fig. 4.2 — Beating an iron nail with a hammer (from the chapter)

Table 4.1 from the textbook — Table 4.1 — as printed in the book (from the chapter)

S.No.	Object / Material	Appearance	Hard / Soft	Effect of hammering	Nature
1	Piece of copper	Lustrous	Hard	Flattens into a sheet	Metal — malleable
2	Piece of aluminium	Lustrous	Hard	Flattens into a sheet	Metal — malleable
3	Iron nail	Lustrous	Hard	Flattens	Metal — malleable
4	Piece of coal	Non-lustrous (dull)	Soft / not as hard as metals	Breaks into pieces	Non-metal — brittle
5	Lump of sulfur	Non-lustrous (dull)	Soft	Breaks into pieces	Non-metal — brittle
6	Block of wood	Non-lustrous	Neither very hard nor very soft	Neither flattens nor breaks	Neither malleable nor brittle (not an element)

Analysis of Table 4.1

Lustrous and hard: copper, aluminium and iron. The shine shown by metals is called metallic lustre, and such materials are called metals.
Coal, sulfur and wood are non-lustrous and not as hard as metals.
Which objects flattened? Copper, aluminium and the iron nail. The property of being beaten into thin sheets is called malleability. Gold and silver are the most malleable metals.
Examples of metal sheets: the thin silver foil (chandi ka varak) on sweets and aluminium foil for wrapping food.
Coal and sulfur break into pieces → they are brittle. Wood does neither → it is neither malleable nor brittle.

Are all metals hard and solid? No.
• Sodium and potassium are so soft that they can be cut with a knife.
• Mercury is a metal that is liquid at room temperature (used in thermometers).

Holistic Lens: What could be the reason that copper is generally considered to have been discovered earlier than iron?

SOLUTION

Copper is often found in nature in a nearly pure (free) form, so early people could pick it up and use it directly. Iron is almost always found combined in ores, so it must first be extracted.
Copper melts at a much lower temperature than iron. Early furnaces could not reach the very high temperature needed to work iron — that needed better furnace technology.
Copper is softer and easier to hammer and shape with simple tools.
That is why the Harappans used copper and gold for utensils and jewellery, but hardly any iron is found from their time.

Once iron came into use, its strength made tools like the plough far better than earlier ones, and it contributed greatly to the progress of civilisation in India.

4.1.2 Ductility

Where do you find the use of metal wires? What is ductility? Are coal and sulfur ductile?

SOLUTION

Uses of metal wires

Electrical fittings — wires of copper and aluminium.
Ornaments — bangles, necklaces, earrings.
Stringed musical instruments — veena, sitar, violin, guitar.
Household items like a tea strainer, wire mesh, and steel ropes.

Ductility = the property of materials by which they can be drawn into wires. It is mainly possessed by metals.
Amazing fact: Gold is so ductile that 1 gram of gold can be drawn into a 2 kilometre-long wire!

Coal and sulfur are NOT ductile — we never see wires made of coal or sulfur; they are brittle and break.

A suspension bridge held by steel wire ropes — **Dive Deeper:** Ropes made of **steel** — a mixture of a metal (iron) and a non-metal (carbon) — support heavy loads in suspension bridges and cranes (from the chapter)

4.1.3 Sonority — Activity 4.2

A4.2

Drop a metal spoon, a coin, a piece of coal and a block of wood from a height. Do you notice any difference in the sound produced?

SOLUTION

Object	Sound produced	Conclusion
Metal spoon	Ringing sound	Sonorous (metal)
Metal coin	Ringing sound	Sonorous (metal)
Piece of coal	Dull sound	Not sonorous (non-metal)
Block of wood	Dull sound	Not sonorous

The property of metals that enables them to produce a ringing sound is called sonority; metals are said to be sonorous.
Everyday examples: the ringing of ghungroos, the school bell, temple bells, and cymbals — all due to the sonority of metals. A visually impaired person can even tell wood from metal by the sound of the walking stick.

4.1.4 Conduction of heat — Activity 4.3

A4.3

A metal spoon and a wooden spoon are immersed in hot water. Which spoon gets hotter? What does this tell us about heat transfer? Why are cooking vessels made of metals?

SOLUTION

Metal and wooden spoons immersed in a glass of hot water — Fig. 4.3 — Metal and wooden spoons immersed in hot water (from the chapter)

Observation. The metal spoon becomes hotter to touch at its upper end than the wooden spoon — even though both were in water of the same temperature for the same time.

What it tells us. Heat travels easily through the metal spoon and reaches its upper end, whereas the wooden spoon transfers heat poorly.

Definitions. The transfer of heat from one point of a material to another is called conduction; materials that transfer heat are conductors.

Conclusion. Metals are good conductors of heat; wood is a poor conductor of heat.

Why metal vessels for cooking? Because metals (aluminium, copper, iron, steel, brass) conduct heat quickly and evenly to the food.
Why wooden/plastic handles? Because these do not conduct heat, so our hands do not get burnt.

4.1.5 Conduction of electricity — Activity 4.4 & Table 4.2

A4.4

Using a tester circuit, test aluminium foil, iron nail, sulfur, copper wire, coal, dry wood, stone, rubber eraser and nylon rope. Which make the bulb glow? Complete Table 4.2. Also — why does an electrician use a screwdriver with a plastic handle and wear rubber gloves?

SOLUTION — TABLE 4.2 (COMPLETED)

Table 4.2 from the textbook — Table 4.2 — as printed in the book (from the chapter)

S.No.	Object / Material	Prediction	Observation (bulb)	Conclusion
1	Piece of aluminium foil	Glows	Glows ✔	Good conductor of electricity (metal)
2	Iron nail	Glows	Glows ✔	Good conductor (metal)
3	Copper wire	Glows	Glows ✔	Good conductor (metal)
4	Lump of sulfur	Does not glow	Does not glow ✘	Poor conductor (non-metal)
5	Piece of coal	Does not glow	Does not glow ✘	Poor conductor
6	Piece of dry wood	Does not glow	Does not glow ✘	Poor conductor
7	Stone	Does not glow	Does not glow ✘	Poor conductor
8	Rubber eraser	Does not glow	Does not glow ✘	Poor conductor
9	Nylon rope	Does not glow	Does not glow ✘	Poor conductor

The pattern

All the materials that make the bulb glow are metals. Materials that let electricity flow easily are good conductors of electricity; those that do not are poor conductors of electricity.

Why the plastic handle and rubber gloves? Because plastic and rubber are poor conductors of electricity. They do not let current pass into the electrician’s body, and so protect him from an electric shock.

4.2 Effect of air and water on iron — Activity 4.5 & Table 4.3

A4.5

In which condition does an iron nail develop brown deposits — dry air only, water only, or both air and water? Complete Table 4.3 and conclude.

SOLUTION — TABLE 4.3 (COMPLETED)

Three glass bottles A, B and C containing iron nails — Fig. 4.4 — Glass bottles containing iron nails: (a) nail + silica gel (dry air), (b) nail in boiled water under an oil layer, (c) nail partly in water, open to air (from the chapter)

Table 4.3 from the textbook — Table 4.3 — as printed in the book (from the chapter)

Glass bottle	Set-up	Presence of water	Presence of air	Observation after 8–10 days
A	Nail + silica gel, capped (silica gel keeps the air dry)	No	Yes (dry air)	No brown deposit — nail stays shining
B	Nail fully in boiled and cooled water with an oil layer on top, capped (oil keeps air out)	Yes	No	No brown deposit
C	Nail partly in water, bottle kept open — nail touches both water and air	Yes	Yes	Brown deposit forms ✔

Conclusion

Step 1. No deposit in A → dry air alone cannot cause it.

Step 2. No deposit in B → water alone (without air) cannot cause it.

Step 3. Deposit in C → both water and air together are essential. Thus moist air is responsible.

Step 4. This brown deposit is called rust, and the process is called rusting.

Corrosion and its prevention

Other metals also change on exposure to air: a green coating on copper, a black coating on silver.
The gradual deterioration of a metal surface caused by air, water or other substances is called corrosion.
Rusting can be prevented by: painting, oiling, greasing, and coating iron with a thin layer of zinc (galvanisation).

The Iron Pillar of Delhi — **Fascinating fact:** The **Iron Pillar of Delhi** — made in the time of Chandragupta II, over **1600 years** ago, about **8 m** high, over **6000 kg** — has **barely any rust**, showing the skill of ancient Indian metallurgy (from the chapter)

4.3 Effect of air and water on other metals — Activity 4.6

A4.6

Burn a magnesium ribbon. What do you observe? What is the white powder? Is its solution acidic, basic or neutral? Also — can you predict the nature of sodium’s oxide?

SOLUTION

Burning magnesium ribbon with a dazzling white flame — Fig. 4.5 — Burning magnesium ribbon (from the chapter)

Observation. The magnesium ribbon burns with a dazzling white flame and changes into a white powder.

The powder. The white powder is magnesium oxide, formed by the reaction of magnesium with the oxygen present in air.

Magnesium + Oxygen → Magnesium oxide

Testing with water. On adding warm water and stirring, a solution is formed. It turns red litmus paper blue → the solution is BASIC.

Litmus papers on a watch glass testing magnesium oxide solution — Fig. 4.6 — Testing the nature of magnesium oxide: red litmus turns blue (from the chapter)

General rule: Oxides of metals are basic in nature.
Nature of sodium’s oxide: sodium is a metal, so sodium oxide is also BASIC. (Sodium is stored in kerosene because it reacts vigorously with oxygen and water, releasing a lot of heat — the kerosene keeps air and moisture away.)

4.4 Substances that behave differently — Activities 4.7 & 4.8

A4.7

Burn sulfur in a gas jar, dissolve the gas in water and test with an indicator. What do you observe?

SOLUTION

Deflagrating spoon, improvised deflagrating spoon and burning of sulfur in a gas jar — Fig. 4.7 — (a) Deflagrating spoon (b) improvised spoon (c) Burning of sulfur in a gas jar (from the chapter)

Step 1. On burning in air (oxygen), sulfur forms sulfur dioxide gas.

Sulfur + Oxygen → Sulfur dioxide

Step 2. When water is added to the gas jar and shaken, the gas dissolves in water and forms sulfurous acid.

Sulfur dioxide + Water → Sulfurous acid

Step 3 — Observation. The solution turns blue litmus paper red → the solution is ACIDIC.

Litmus papers on a watch glass testing the solution of sulfur dioxide — Fig. 4.7(d) — Testing of the solution with litmus papers: blue litmus turns red (from the chapter)

General rule: Oxides of non-metals are acidic in nature.

A4.8

Add a small amount of water to some sulfur powder in a glass tumbler. What do you observe? Does sulfur behave in water the way metals do?

SOLUTION

No reaction takes place when sulfur is placed in water. Generally, non-metals do not react with water.
Phosphorus is an exception in the opposite sense — it is stored in water because it catches fire when exposed to air.

What are non-metals?

Substances like sulfur and phosphorus are non-metals. They are usually:

Soft and dull (non-lustrous) in appearance
Neither malleable nor ductile (they are brittle)
Not sonorous
Poor conductors of heat and electricity
Their oxides are acidic

Other non-metals: oxygen, hydrogen, nitrogen, carbon, chlorine, iodine.

Important: Materials like plastic, glass, wood, rubber and paper are NOT classified as metals or non-metals — because they are not elements.
Dive Deeper: Metals and non-metals are sub-categories of elements. An element is a substance that cannot be broken down into simpler substances. At present 118 elements are known.

4.5 Are non-metals essential in everyday life? Can you think of uses of oxygen and other non-metals?

SOLUTION

Non-metal	Why it is essential
Oxygen	We breathe it in — we cannot survive without it. Also used in hospitals (oxygen cylinders), for burning fuels, in welding, and by divers and mountaineers.
Carbon	The building block of all life forms — a key component of proteins, fats and carbohydrates needed for growth and energy.
Nitrogen	Used to manufacture fertilisers and other chemicals; an essential nutrient for plant growth.
Chlorine	Commonly used in water purification.
Iodine	Its solution is applied on wounds as an antiseptic.

Science and Society: Many metals and their alloys (mixtures of two or more metals, or of a metal and a non-metal) are used for utensils, tools and modern technology — zirconium in atomic energy, titanium in aerospace. In India, iron and aluminium are recycled to reduce waste and support sustainability.

Let Us Enhance Our Learning (Exercise)

Which metal is commonly used to make food packaging materials, as it is cheaper and its thin sheets can be folded easily into any shape?
(i) Aluminium (ii) Copper (iii) Iron (iv) Gold

SOLUTION

Answer: (i) Aluminium

Aluminium is highly malleable — it can be beaten into very thin sheets (aluminium foil) that fold easily.
It is cheap and available in plenty; it is also light and does not rust like iron.
Copper and gold are costly; iron is heavy and would rust — none of them is suitable for food wrapping.

Which of the following metals catches fire when it comes in contact with water?
(i) Copper (ii) Aluminium (iii) Zinc (iv) Sodium

SOLUTION

Answer: (iv) Sodium

Sodium reacts vigorously with water and oxygen, and a lot of heat is generated — so it can catch fire.
This is why sodium is stored in kerosene, which keeps it away from air and moisture.
Copper, aluminium and zinc do not catch fire on contact with water.

State with reasons whether the statements are True [T] or False [F].

SOLUTION

Statement	T / F	Reason
(i) Aluminium and copper are examples of non-metals used for making utensils and statues.	False	Aluminium and copper are metals — they are lustrous, hard, malleable, ductile and good conductors. (The use mentioned is correct; only the word “non-metals” is wrong.)
(ii) Metals form oxides with oxygen, the solution of which turns blue litmus red.	False	Metal oxides are BASIC. Their solution turns red litmus BLUE (as magnesium oxide did in Activity 4.6). It is non-metal oxides that are acidic and turn blue litmus red.
(iii) Oxygen is a non-metal essential for respiration.	True	Oxygen is a non-metal; we breathe it in and cannot survive without it.
(iv) Copper vessels are used for boiling water because they are good conductors of electricity.	False	Copper vessels are used because copper is a good conductor of HEAT. Being a good conductor of electricity has nothing to do with boiling water.

Why are only a few metals suitable for making jewellery?

SOLUTION

Only metals such as gold, silver and platinum are used for jewellery, because jewellery needs a special combination of properties:

Highly lustrous — they have a beautiful, lasting shine (metallic lustre).
Most malleable and ductile — they can be beaten into thin sheets and drawn into fine wires, so they can be shaped into delicate designs.
Do not corrode — they do not rust or get a black/green coating easily, so the ornament keeps its shine for years. (Iron would rust, copper turns green, silver slowly turns black.)
Rare and attractive, hence precious.
Metals like sodium and potassium are too soft and reactive, and mercury is a liquid — clearly unusable.

Match Column I (uses) with the jumbled names in Column II.

SOLUTION

Column I and Column II matching table from the textbook — The matching table as printed in the book (from the chapter)

Column I (use)	Jumbled word	Unjumbled name	Match
(i) Used in electrical wiring	P E P O R C	COPPER (metal)	(c)
(ii) Most malleable and ductile	O G D L	GOLD (metal)	(e)
(iii) Living organisms cannot survive without it	E N X Y G O	OXYGEN (non-metal)	(a)
(iv) Plants grow healthy when fertilisers containing it are added to the soil	T E N G O I N R	NITROGEN (non-metal)	(d)
(v) Used in water purification	N E C O H I R L	CHLORINE (non-metal)	(b)

Final answers: (i) → (c) • (ii) → (e) • (iii) → (a) • (iv) → (d) • (v) → (b)

What happens when oxygen reacts with magnesium and with sulfur? What are the main differences in the nature of the products formed?

SOLUTION

With magnesium (a metal): the ribbon burns with a dazzling white flame and forms a white powder, magnesium oxide.

Magnesium + Oxygen → Magnesium oxide

Dissolved in water it turns red litmus blue → it is BASIC.

With sulfur (a non-metal): sulfur burns to form sulfur dioxide gas, which dissolves in water to give sulfurous acid.

Sulfur + Oxygen → Sulfur dioxide ; Sulfur dioxide + Water → Sulfurous acid

It turns blue litmus red → it is ACIDIC.

Point of difference	Magnesium (metal)	Sulfur (non-metal)
Product with oxygen	Magnesium oxide (white powder)	Sulfur dioxide (gas)
Nature of the oxide	Basic	Acidic
Effect on litmus	Turns red litmus blue	Turns blue litmus red

Main difference: Metal oxides are basic, while non-metal oxides are acidic.

Complete the following flow chart.

SOLUTION

Flow chart to be completed, from the textbook — The flow chart as printed in the book (from the chapter)

The completed flow chart

Blank	Correct answer	Why
1st “?” (before + Air + Heat)	Magnesium (ribbon)	On burning in air it forms a white ash.
“Ash”	Magnesium oxide	The white powder formed by magnesium + oxygen.
2nd “?” (after adding Water)	Solution of magnesium oxide (a basic solution)	Metal oxide dissolves in water to give a basic solution.
3rd “?” (change in blue litmus solution)	No change — it remains blue	A base does not change blue litmus; it changes red litmus to blue (which is why the other box says “Blue”).

From iron, copper, sulfur, coal, plastic, wood, cardboard — which material would you choose to make a pan for boiling water, and why?

SOLUTION

List of materials given in the question — The materials given in the question (from the chapter)

Choice: COPPER (iron is the next best choice).

Why copper?

It is a metal and a very good conductor of heat — heat passes quickly into the water, so it boils fast.
It is hard, strong and malleable — it can be shaped into a pan and will not break.
It has a high melting point — it will not melt or burn on the flame.
It does not rust like iron (iron pans work well too, but they rust in moist air).

Why not the others?

Material	Reason it is unsuitable
Sulfur, coal	Non-metals — brittle, poor conductors of heat, and they burn on a flame.
Plastic	Melts on heating and is a poor conductor of heat.
Wood, cardboard	Catch fire, and are poor conductors of heat.
Iron	Usable (good conductor, strong), but it rusts — copper is a better choice.

Three iron nails are dipped in oil, water and vinegar. Which nail will not rust, and why?

SOLUTION

The nail dipped in OIL will not rust.

Nail dipped in	Rusts?	Reason
Oil	Does NOT rust ✔	The oil forms a protective layer that keeps both air and moisture away from the iron. Rusting needs air AND water together (Activity 4.5) — oil cuts off both. (Oiling is in fact a method of preventing rusting.)
Water	Rusts	Ordinary water has dissolved air (oxygen) in it, so both water and air are present.
Vinegar	Rusts (even faster)	Vinegar is an acid and it also contains water and dissolved air — acidic conditions speed up corrosion.

Q10

How do the different properties of metals and non-metals determine their uses in everyday life?

SOLUTION

Every use follows directly from a property — that is the big idea of this chapter.

Property	Which materials	Use in everyday life
Malleability	Metals (gold, silver, aluminium)	Aluminium foil, silver varak on sweets, metal sheets, utensils, car bodies
Ductility	Metals (copper, aluminium, gold)	Electrical wires, ornaments, strings of veena/sitar/guitar, tea strainer, steel ropes for bridges and cranes
Sonority	Metals	Bells, ghungroos, cymbals, musical instruments
Good conductor of heat	Metals	Cooking vessels, pans, kettles, tawa
Poor conductor of heat	Wood, plastic (and non-metals)	Handles of vessels, ladles, oven mitts
Good conductor of electricity	Metals (copper)	Electrical wiring, switches, plug pins
Poor conductor of electricity	Plastic, rubber	Covering of wires, screwdriver handles, electrician’s gloves and shoes
Hardness & strength	Iron, steel	Tools, machines, bridges, buildings, farming implements
Lustre + resistance to corrosion	Gold, silver, platinum	Jewellery, coins, decorative items
Chemical properties of non-metals	Oxygen, carbon, nitrogen, chlorine, iodine	Respiration, food/energy, fertilisers, water purification, antiseptic

Q11

Iron is protected from rusting by a thin coating of zinc. Since sulfur does not react with water, can sulfur be used for this purpose? Justify.

SOLUTION

No, sulfur cannot be used to coat iron. Not reacting with water is only one requirement — a protective coating needs much more.

Justification

1. Sulfur is brittle, not malleable or ductile. It cannot be beaten or drawn into a thin, continuous layer; it would only crumble into powder. Zinc is a metal, so it can be spread as a thin, unbroken film (galvanisation).

2. A sulfur coat would not stick. It would flake and crack off, leaving gaps. Even a small gap lets moist air reach the iron, and rusting begins there.

3. Sulfur is soft and low-melting. It would be rubbed off or melt in ordinary use, unlike a tough zinc layer.

4. Zinc gives extra protection. Zinc itself resists corrosion and shields the iron underneath — which is why galvanised sheets, buckets and pipes last long.

Conclusion: Rusting is prevented by completely cutting off air and water with a strong, continuous, well-stuck layer — as given by zinc, paint, oil or grease. Sulfur cannot form such a layer.

Q12

An ironsmith heats iron before making tools. Why is heating necessary?

SOLUTION

Step 1. At room temperature, iron is very hard and stiff. Hammering cold iron is extremely difficult, and it may crack or break.

Step 2. On heating in the furnace (with coal), the iron becomes red hot and soft.

Step 3. Hot iron becomes much more malleable — it can be beaten and bent into the desired shape (an axe, a khurpi, a tawa) with far less force.

Step 4. As it cools, it keeps the new shape and regains its hardness and strength.

In one line: heating increases the malleability of iron, so the ironsmith can shape it easily without breaking it.

Exploratory Projects — guidance

GUIDANCE

1. India’s famous metal art styles

Metal art	State it is famous in	About it
Dhokra	Chhattisgarh, Odisha, West Bengal, Jharkhand	Ancient lost-wax casting in brass/bronze — tribal figures and animals
Bidriware	Bidar, Karnataka	Silver inlay on a blackened zinc-copper alloy
Pembarthi	Pembarthi, Telangana	Fine sheet-metal (brass) work — made possible by malleability
Kamrupi	Assam (Kamrup region)	Traditional bell-metal and brass craft

Make a collage of their photographs and note which property of metals each craft depends on.

2. Metals on the map of India (mark these states)

Iron ore: Odisha, Jharkhand, Chhattisgarh, Karnataka, Goa
Gold: Karnataka (Kolar, Hutti), Andhra Pradesh
Aluminium (bauxite): Odisha, Jharkhand, Gujarat, Maharashtra, Chhattisgarh
Copper: Rajasthan (Khetri), Jharkhand, Madhya Pradesh

3. Metals and non-metals in a smartphone

Copper — the wiring and circuits (good conductor of electricity).
Aluminium — light, strong body/frame.
Gold & silver — thin coatings on connectors; they conduct well and do not corrode.
Lithium (a metal) — the rechargeable battery.
Silicon — the chip; carbon in the plastics; oxygen in the glass screen.

4. Debate: should the use of metals for comfort and luxury be increased or decreased?

Should be increased (for)	Should be decreased (against)
Metals are strong, durable and long-lasting; they can be recycled again and again (iron and aluminium are widely recycled in India); they make life safer and more comfortable.	Mining damages forests, soil and water; the ores are limited and will not last forever; extraction uses huge energy and causes pollution; luxury use wastes a resource needed for essential things like tools, bridges and hospitals.

A balanced conclusion: use metals where they are really needed, avoid wasteful luxury use, and recycle as much as possible — this is what sustainability means.

Chapter 4: The World of Metals and Non-metals Class 8th Science (Curiosity) NCERT Solution

Chapter 4 — The World of Metals and Non-metals

Analysis of Table 4.1

Uses of metal wires

The pattern

Conclusion

Corrosion and its prevention

What are non-metals?

Why copper?

Why not the others?

Justification

1. India’s famous metal art styles

2. Metals on the map of India (mark these states)

3. Metals and non-metals in a smartphone

4. Debate: should the use of metals for comfort and luxury be increased or decreased?

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