Question 1

Can you give some examples of metal sheets? (Page 43)

Accepted Answer

Some examples of metal sheets are silver foil and aluminium foil.

Source: This question is from The World of Metals and Non-metals, Science &mdash; Class 7, CBSE Board.
Key Concepts CoveredThis question tests your understanding of the following concepts from the chapter The World of Metals and Non-metals: Metal, Sheets, Page, The World of Metals and Non-metals, Science. These are fundamental topics in Science that students are expected to master as part of the CBSE Class 7 curriculum.A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Science papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach This QuestionRead the question carefully and identify what is being asked. Break down complex questions into smaller parts. Use the terminology and concepts discussed in this chapter. Structure your answer logically — begin with a definition or key statement, then provide supporting details. Review your answer to ensure it addresses all parts of the question completely.
Key Points to RememberRead the question carefully and identify all parts before answering.
Use the terminology specific to this subject and chapter.
Review the textbook content for this chapter before attempting questions.
Practice writing concise, well-structured answers within time limits.
Related Questions from The World of Metals and Non-metalsQ11: You are provided with the following materials. Discuss which material would be your choice to make...
Q12: You are provided with three iron nails, each dipped in oil, water and vinegar. Which iron nail will...
Q13: How do the different properties of metals and non-metals determine their uses in everyday life?
Q14: One of the methods of protecting iron from getting rusted is to put a thin coating of zinc metal...
Q15: An ironsmith heats iron before making tools Why is heating necessary in this process?
Practice more questions from The World of Metals and Non-metals &mdash; Science, Class 7 CBSE

Question 2

Can you name some metals that are used for making cooking vessels? (Page 46)

Accepted Answer

Metals like aluminium, copper, and stainless steel are commonly used for making cooking vessels.

Source: This question is from The World of Metals and Non-metals, Science &mdash; Class 7, CBSE Board.
Key Concepts CoveredThis question tests your understanding of the following concepts from the chapter The World of Metals and Non-metals: Metals, Making, Cooking, Vessels, Page, The World of Metals and Non-metals. These are fundamental topics in Science that students are expected to master as part of the CBSE Class 7 curriculum.A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Science papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach This QuestionRead the question carefully and identify what is being asked. Break down complex questions into smaller parts. Use the terminology and concepts discussed in this chapter. Structure your answer logically — begin with a definition or key statement, then provide supporting details. Review your answer to ensure it addresses all parts of the question completely.
Key Points to RememberRead the question carefully and identify all parts before answering.
Use the terminology specific to this subject and chapter.
Review the textbook content for this chapter before attempting questions.
Practice writing concise, well-structured answers within time limits.
Related Questions from The World of Metals and Non-metalsQ11: You are provided with the following materials. Discuss which material would be your choice to make...
Q12: You are provided with three iron nails, each dipped in oil, water and vinegar. Which iron nail will...
Q13: How do the different properties of metals and non-metals determine their uses in everyday life?
Q14: One of the methods of protecting iron from getting rusted is to put a thin coating of zinc metal...
Q15: An ironsmith heats iron before making tools Why is heating necessary in this process?
Practice more questions from The World of Metals and Non-metals &mdash; Science, Class 7 CBSE

Question 3

Have you ever seen an electrician using a screwdriver? What type of material is used for making its handle? (Page 47)

Accepted Answer

Yes. The handle of a screwdriver is usually made of plastic or rubber.NCERT Class 7 Science Chapter 4 Question Answer The World of Metals and Non metals (Exercise)

Source: This question is from The World of Metals and Non-metals, Science &mdash; Class 7, CBSE Board.
Key Concepts CoveredThis question tests your understanding of the following concepts from the chapter The World of Metals and Non-metals: Ever, Seen, Electrician, Screwdriver, Material, Making. These are fundamental topics in Science that students are expected to master as part of the CBSE Class 7 curriculum.A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Science papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach This QuestionRead the question carefully and identify what is being asked. Break down complex questions into smaller parts. Use the terminology and concepts discussed in this chapter. Structure your answer logically — begin with a definition or key statement, then provide supporting details. Review your answer to ensure it addresses all parts of the question completely.
Key Points to RememberRead the question carefully and identify all parts before answering.
Use the terminology specific to this subject and chapter.
Review the textbook content for this chapter before attempting questions.
Practice writing concise, well-structured answers within time limits.
Related Questions from The World of Metals and Non-metalsQ11: You are provided with the following materials. Discuss which material would be your choice to make...
Q12: You are provided with three iron nails, each dipped in oil, water and vinegar. Which iron nail will...
Q13: How do the different properties of metals and non-metals determine their uses in everyday life?
Q14: One of the methods of protecting iron from getting rusted is to put a thin coating of zinc metal...
Q15: An ironsmith heats iron before making tools Why is heating necessary in this process?
Practice more questions from The World of Metals and Non-metals &mdash; Science, Class 7 CBSE

Question 4

Match the uses of metals and non-metals given in Column I with the jumbled names of metals and non-metals given in Column II.

Accepted Answer

Column I
Column II

(i) Used in electrical wiring
(c) PEPORC

(ii) Most malleable and ductile
(e) OGDL

(iii) Living Organisms cannot survive without it.
(a) ENXYGO

(iv) Plants grow healthy when fertilisers containing it are added to the soil.
(d) TENGOINR

(v) Used in water purification
(b) NECOHIRL

Question 5

State with reason(s) whether the following statements are True [T] or False [F].
(i) Aluminium and copper are examples of non-metals used for making utensils and statues.
(ii) Metals form oxides when combined with oxygen, the solution of which turns blue litmus paper to red.
(iii) Oxygen is a non-metal essential for respiration.
(iv) Copper vessels are used for boiling water because they are good conductors of electricity.

Accepted Answer

[F], Aluminium and copper are examples of metals, not non-metals.[F], Metal oxides are basic, they turn red litmus paper to blue.[T], Oxygen is a non-metal and is essential for respiration.[F], Copper vessels are used for boiling water because copper is a good conductor of heat.

Question 6

Why are only a few metals suitable for making jewellery?

Accepted Answer

Only a few metals are suitable for making jewellery because they are lustrous. These metals are also soft, which allows them to be easily shaped into various designs. Also, they do not react easily with air or water, so they do not rust or lose their shine over time.

Question 7

Match the uses of metals and non-metals given in Column I with the jumbled names of metals and non-metals given in Column II.
Column I
Column II
(i) Used in electrical wiring
(a) ENXYGO
(ii) Most malleable and ductile
(b) NECOHIRL
(iii) Living Organisms cannot survive without it.
(c) PEPORC
(iv) Plants grow healthy when fertilisers containing it are added to the soil.
(d) TENGOINR
(v) Used in water purification
(e) OGDL

Accepted Answer

Column IColumn II(i) Used in electrical wiring(c) PEPORC(ii) Most malleable and ductile(e) OGDL(iii) Living Organisms cannot survive without it.(a) ENXYGO(iv) Plants grow healthy when fertilisers containing it are added to the soil.(d) TENGOINR(v) Used in water purification(b) NECOHIRL

Question 8

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

Accepted Answer

When oxygen reacts with magnesium, it forms magnesium oxide, which is a basic oxide and turns red litmus paper to blue. However, when oxygen reacts with sulphur, it forms sulphur dioxide, which is an acidic oxide and turns blue litmus paper to red.

Question 9

You are provided with the following materials. Discuss which material would be your choice to make a pan that is most suitable for boiling water and why?

Accepted Answer

For boiling water, the pan must be made of a material that is a good conductor of heat. Among the given materials, only iron and copper are metals and both are good conductors of heat. However, copper is the best choice because it is highly resistant to rust compared to iron. Therefore, a pan made of copper is the most suitable choice for boiling water.

Question 10

You are provided with three iron nails, each dipped in oil, water and vinegar. Which iron nail will not rust, and why?

Accepted Answer

The iron nail dipped in oil will not rust because the oil prevents the iron nail from coming into contact with air or moisture. It forms a protective layer on the metal, which prevents rusting.

Question 11

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

Accepted Answer

Metals and non-metals have various properties that make them useful in our everyday life.Metals:Metals are malleable, for example, aluminium foil is used for wrapping food.Metals are ductile, wires made of copper or aluminium are used in electrical fittings.Metals are sonorous, they produce a ringing sound.Metals are good conductors of heat, so they are used in making cooking vessels.Metals are good conductors of electricity, making them ideal for electrical wires.Non-metals:Generally non-metals are poor conductor of heat and electricity; for example, sulphur and carbon are used in insulating materials to prevent the transfer of heat or electricity.Non-metals are brittle: for example, sulphur and phosphoros are often used in matchsticks as they break easily or react quickly.Non-metals are gaseous at room temperature: for example, oxygen is essential for breathing.Non-metals are non-lustrous: carbon (as graphite) are used in pencils and dry cell batteries.

Question 12

One of the methods of protecting iron from getting rusted is to put a thin coating of zinc metal over it. Since sulphur does not react with water, can it be used for this purpose? Justify your

Accepted Answer

Answer:No, sulphur cannot be used to protect iron from rusting. While sulphur does not react with water, it does not have the property of forming a protective layer over iron like zinc. It cannot prevent air and moisture from coming into contact with the iron.

Question 13

An ironsmith heats iron before making tools Why is heating necessary in this process?

Accepted Answer

For making tools, a ironsmith first heats a piece of iron until it becomes red-hot. This is because heating makes the iron soft, more malleable and easier to bend, hammer and mould into the desired shape for tools.Class 7 The World of Metals and Non metals Question Answer (Activities)Activity 4.1: Let Us Explore (Pages 42-43)Observation:Table 4.1: Appearance, hardness, and effect of hammering on different objects or materialsObject/MaterialAppearance (lustrous/non-lustrous)Hard/SoftEffect of hammering (fattens/ breaks into pieces)Piece of copperLustrousHardFlattensPiece of aluminiumLustrousHardFlattensIron nailLustrousHardFlattensPiece of coalNon-lustrousSoftbreaks into piecesLump of sulphur (pea-sized)Non-lustrousSoftbreaks into piecesBlock of woodNon-lustrousHard but not hard as metalNeither flattens nor breaks into piecesConclusion:• Materials like copper, aluminium and iron are lustrous, hard and can be flattened into thin sheets.• Materials like coal, sulphur are non-lustrous, soft and breaks into pieces. Wood is neither malleable nor brittle.Activity 4.2: Let Us Investigate (Pages 45 – 46)Observation: Metal spoon and metal coin produce a ringing sound. On the other hand, coal and wood produce dull sounds.Conclusion: Metals are sonorous, they produce a ringing sound.Activity 4.3: Let us Investigate (Pages 46-47)Observation: Metal spoon is hotter to touch than wooden spoon.Conclusion: Heat transfers through the metal spoon easily, making it hotter. While heat transfers through the wooden spoon poorly. Hence, metals are good conductors of heat, but wood is a poor conductor of heat.Activity 4.4: Let Us Design And Create (Pages 47-48)Observation: Table 4.2: Conduction of electricity by different objects or materialsObject/ MaterialObservation (bulb glows/ does not glow)Good conductor of electricity or poor conductor of electricityPiece of aluminium foilBulb slowsGood conductor of electricitvIron nailBulb glowsGood conductor of electricitvLump of sulphur (peasized)Bulb does not glowPoor conductor of electricityCooDer wireBulb glowsGood conductor of electricityPiece of coalBulb does not glowPoor conductor of electricityPiece of dry woodBulb does not glowPoor conductor of electricityStoneBulb does not glowPoor conductor of electricityConclusion:• Materials like aluminium, iron and copper allows electricity to pass through them. So, they are good conductors of electricity.• Materials like sulphur, coal, dry wood, stone, eraser and nylon do not allow electricity to pass through them. So, they are poor conductors of electricity.Activity 4.5: Let Us Experiment (Pages 49-50)Observation: Table 4.3: Formation of brown deposit on iron nailsGlass BottleAConditionsObservationsPresence of water (Yes/No)Presence of air (Yes/No)ANoYesNo brown denosit on iron nailBYesNoNo brown denosit on iron nailCYesYesBrown deposits on iron nailConclusion:  The presence of both air and water is essential for the brown deposit to be formed on iron (rusting of iron).Activity 4.6: Let Us Investigate (demonstration activity) (Page 51)Observation:• Magnesium ribbon burns with a dazzling white flame and changes into a white powder (ash).• The solution changes the colour of red litmus paper to blue.Conclusion:• Magnesium burns with oxygen in the air and produces magnesium oxide.• The oxides of metals are generally basic in nature.Activity 4.7: Let Us Experiment (demonstration activity) (Pages 52-53)Observation: The solution obtained after the addition of water to the glass jar turns blue litmus paper to red.Conclusion:• Sulphur burns with oxygen in the air and produces sulphur dioxide gas.• On dissolving sulphur dioxide gas in water, sulphurous acid is formed, which turns blue litmus paper to red. Thus, oxides of non-metals are acidic in nature.Activity 4.8: Let Us Explore (Page 53)Observation: When sulphur is placed in water, no reaction occurs.Conclusion: Sulphur does not react with water.