CBSE Class 7 Science Chapter 4: The World of Metals and Non-metals — Assertion & Reason
CBSE Class 7 Science Assertion & Reason
Expert crafted · Instant PDF download · 2026-27
The following Assertion and Reason questions are based on Chapter 4: The World of Metals and Non-metals from the NCERT Class 7 Science textbook Curiosity. Each question has four options — read both the Assertion (A) and Reason (R) carefully before selecting your answer.
How to attempt Assertion & Reason questions:
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Assertion & Reason Questions
1
Assertion (A): Metals like iron, copper, and aluminium can be beaten into thin sheets.
Reason (R): The property by which materials can be beaten into thin sheets is called malleability.
Reason (R): The property by which materials can be beaten into thin sheets is called malleability.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Because these metals possess the physical property of malleability, they can be flattened into sheets without breaking.
2
Assertion (A): A piece of coal gets flattened into a thin sheet when beaten hard with a hammer.
Reason (R): Coal is a non-metal and is brittle in nature.
Reason (R): Coal is a non-metal and is brittle in nature.
Answer: (d)
A is false, but R is true. Coal is brittle, meaning it shatters into pieces when struck rather than flattening into a sheet.
3
Assertion (A): Copper and aluminium are widely used to make electrical wires.
Reason (R): The property by which materials can be drawn into wires is called ductility, which is mainly possessed by metals.
Reason (R): The property by which materials can be drawn into wires is called ductility, which is mainly possessed by metals.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Copper and aluminium are highly ductile metals, allowing them to be stretched into the long, continuous wires needed for electrical circuits.
4
Assertion (A): All metals are found in a solid state at room temperature.
Reason (R): Mercury is a metal that is found in a liquid state at room temperature.
Reason (R): Mercury is a metal that is found in a liquid state at room temperature.
Answer: (d)
A is false, but R is true. While most metals are solid, mercury is a notable exception that exists as a liquid at room temperature.
5
Assertion (A): Sodium is stored in kerosene.
Reason (R): Sodium reacts vigorously with oxygen and moisture present in the atmospheric air.
Reason (R): Sodium reacts vigorously with oxygen and moisture present in the atmospheric air.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Storing sodium in kerosene blocks its exposure to air and water, preventing dangerous and heat-generating chemical reactions.
6
Assertion (A): School bells are made of metals rather than wood or plastic.
Reason (R): Metals are sonorous in nature and produce a ringing sound when struck.
Reason (R): Metals are sonorous in nature and produce a ringing sound when struck.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. The specific property of sonority allows metals to ring out loudly, making them the perfect material for bells.
7
Assertion (A): The handles of metallic cooking utensils are usually made of wood or hard plastic.
Reason (R): Wood and plastic are poor conductors of heat and protect our hands from burning.
Reason (R): Wood and plastic are poor conductors of heat and protect our hands from burning.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Because insulators like wood and plastic do not transfer the heat from the hot cooking pan, they keep the handles safe to touch.
8
Assertion (A): An electrician wears rubber gloves while working with live electrical circuits.
Reason (R): Rubber is an electrical insulator and protects the electrician from electric shocks.
Reason (R): Rubber is an electrical insulator and protects the electrician from electric shocks.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Rubber is a poor conductor of electricity, meaning it blocks the flow of current into the electrician's body.
9
Assertion (A): An iron nail kept in a completely dry glass bottle does not rust over time.
Reason (R): The presence of both water (moisture) and air (oxygen) is essential for the rusting of iron.
Reason (R): The presence of both water (moisture) and air (oxygen) is essential for the rusting of iron.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Rusting is a chemical process that requires moisture. Without water in the dry air, the brown deposit cannot form.
10
Assertion (A): Applying a layer of oil on an iron object speeds up its rusting process.
Reason (R): A layer of oil prevents the iron surface from coming into direct contact with moist air.
Reason (R): A layer of oil prevents the iron surface from coming into direct contact with moist air.
Answer: (d)
A is false, but R is true. Applying oil actually prevents or slows down rusting because it acts as a barrier against moisture and oxygen.
11
Assertion (A): Iron objects can be protected from rusting by a process called galvanisation.
Reason (R): Galvanisation involves applying a protective layer of zinc metal over the iron surface.
Reason (R): Galvanisation involves applying a protective layer of zinc metal over the iron surface.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Coating iron with zinc seals the iron away from the atmosphere, effectively stopping corrosion.
12
Assertion (A): When magnesium ribbon burns in the air, it produces an acidic oxide.
Reason (R): Magnesium is a metal, and generally, oxides of metals are basic in nature.
Reason (R): Magnesium is a metal, and generally, oxides of metals are basic in nature.
Answer: (d)
A is false, but R is true. Magnesium produces magnesium oxide, which turns red litmus blue, proving it is a basic oxide, not acidic.
13
Assertion (A): The solution formed by dissolving sulfur dioxide gas in water turns blue litmus paper to red.
Reason (R): Sulfur is a non-metal, and the oxides of non-metals are generally acidic in nature.
Reason (R): Sulfur is a non-metal, and the oxides of non-metals are generally acidic in nature.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Sulfur burns to form sulfur dioxide, which dissolves in water to form sulfurous acid, changing the blue litmus paper to red.
14
Assertion (A): Phosphorus is stored in water.
Reason (R): Phosphorus catches fire vigorously when exposed to atmospheric air.
Reason (R): Phosphorus catches fire vigorously when exposed to atmospheric air.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. By keeping it submerged in water, the highly reactive non-metal phosphorus is shielded from the oxygen it needs to ignite.
15
Assertion (A): Materials like plastic, wood, and rubber are not classified as metals or non-metals in chemistry.
Reason (R): Metals and non-metals are sub-categories of elements, and plastic, wood, and rubber are not elements.
Reason (R): Metals and non-metals are sub-categories of elements, and plastic, wood, and rubber are not elements.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. An element is a pure substance that cannot be broken down further. Things like wood and plastic are complex mixtures and compounds, not basic elements.
16
Assertion (A): Non-metals are not very essential for our daily lives compared to metals.
Reason (R): Oxygen is a non-metal that is absolutely necessary for the survival and respiration of all living beings.
Reason (R): Oxygen is a non-metal that is absolutely necessary for the survival and respiration of all living beings.
Answer: (d)
A is false, but R is true. Non-metals are profoundly essential to life. The very oxygen we breathe and the carbon that builds our bodies are non-metals.
17
Assertion (A): Carbon is considered an essential building block for all life forms.
Reason (R): Carbon is a key component of proteins, fats, and carbohydrates, which are necessary for growth and energy.
Reason (R): Carbon is a key component of proteins, fats, and carbohydrates, which are necessary for growth and energy.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Because carbon forms the structural backbone of essential biological molecules, it is fundamental to all living organisms.
18
Assertion (A): A solution of iodine is frequently applied to wounds.
Reason (R): Iodine is a non-metal that acts as an effective antiseptic to prevent infection.
Reason (R): Iodine is a non-metal that acts as an effective antiseptic to prevent infection.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. The specific chemical properties of iodine make it an excellent agent for cleaning and treating cuts and scrapes.
19
Assertion (A): Chlorine is commonly used in water purification processes.
Reason (R): Chlorine is a highly malleable and ductile non-metal.
Reason (R): Chlorine is a highly malleable and ductile non-metal.
Answer: (c)
A is true, but R is false. Chlorine is used to purify water, but it is a gas, so it cannot be malleable or ductile (properties belonging only to solid metals).
20
Assertion (A): The 1600-year-old Iron Pillar of Delhi has barely any rust on it.
Reason (R): It was made using advanced ancient Indian metallurgy techniques that resist the process of rusting.
Reason (R): It was made using advanced ancient Indian metallurgy techniques that resist the process of rusting.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. The remarkable lack of corrosion on the pillar is a direct result of the highly skilled metal technology developed in ancient India.
❓ Frequently Asked Questions
What is covered in CBSE Class 7 Science Chapter 4 The World of Metals and Non-metals?
This chapter covers all key topics from The World of Metals and Non-metals as per CBSE 2026-27 syllabus.
Is this Assertion & Reason useful for CBSE board exams?
Yes, designed for CBSE Class 7 board exam preparation covering the complete syllabus.
Are these CBSE Class 7 Science Assertion & Reason updated for 2026-27?
Yes, all content at eBookPublisher is updated as per the latest 2026-27 CBSE syllabus.
How many chapters are in CBSE Class 7 Science?
All chapters of CBSE Class 7 Science are covered at eBookPublisher with free Assertion & Reason for each chapter.
Can I study The World of Metals and Non-metals online for free?
Yes, complete Assertion & Reason for The World of Metals and Non-metals is available free at eBookPublisher. Study online directly — no download needed.
Where can I get a complete Assertion & Reason book for CBSE Class 7 Science?
You can purchase the complete expert-crafted Assertion & Reason book for CBSE Class 7 Science at eBookPublisher.in. Instant PDF download after payment.