The World of Metals and Non-metals explains how materials behave differently based on their properties. Metals are generally lustrous, malleable, ductile, sonorous and good conductors, while non-metals usually lack these properties.
Important Questions Class 7 Science Chapter 4 help students revise how metals and non-metals differ in appearance, strength, heat conduction, electrical conduction, reaction with oxygen, rusting, corrosion and daily-life uses.
Class 7 Science Chapter 4 begins with Yashwant and Anandi visiting local ironsmiths in Rajasthan. They watch an ironsmith heat and hammer iron to make tawas, buckets, tongs, spades, axes and rakes. This scene shows why the properties of metals matter in daily life.
Students then test copper, aluminium, iron, coal, sulfur and wood to compare their behaviour. The chapter explains why metals form sheets and wires, why bells ring, why cooking vessels use metals, why electrician tools have plastic handles, and why iron rusts in moist air.
Key Takeaways from Class 7 Science Chapter 4
| Detail |
Information |
| Chapter Name |
The World of Metals and Non-metals |
| Class |
7 |
| Subject |
Science |
| Main Concept |
Properties and uses of metals and non-metals |
| Important Properties |
Lustre, hardness, malleability, ductility, sonority, conduction |
| Important Reaction |
Metals and non-metals react with oxygen to form oxides |
| Rusting Condition |
Iron rusts in the presence of both air and water |
| Question Types |
MCQs, short answers, long answers, activity-based questions |
Important Questions Class 7 Science Chapter 4 with Answers
These questions cover the main ideas of the chapter. Students should focus on properties, examples, observations and reasons.
Important Questions Class 7 Science Chapter 4: Basic Definitions
Q1. What are metals and non-metals?
Metals are elements that generally show lustre, hardness, malleability, ductility, sonority and good conduction of heat and electricity. Iron, copper and aluminium are common metals.
Non-metals are elements that are generally dull, brittle and poor conductors of heat and electricity. Sulfur, carbon, oxygen, nitrogen and chlorine are examples of non-metals.
Q2. Why did the ironsmith heat iron before hammering it?
The ironsmith heated iron because hot iron becomes easier to shape. Heating makes the metal softer and more workable.
After heating, the ironsmith can beat iron into useful shapes like axes, spades and tongs. This shows the practical use of malleability.
Q3. What is metallic lustre?
Metallic lustre is the shiny appearance shown by metals. Fresh surfaces of copper, aluminium and iron usually show lustre.
Non-metals such as coal and sulfur generally look dull. This difference helps students identify metals during observation-based activities.
Q4. Are all metals hard and solid?
No, all metals are not hard and solid. Sodium and potassium are soft metals and can be cut with a knife.
Mercury is a metal found in liquid state at room temperature. These examples show that metal properties have exceptions.
Q5. Why are gold and silver used for jewellery?
Gold and silver are used for jewellery because they are lustrous, malleable and ductile. They can be shaped into thin sheets and fine wires.
They also resist damage better than many other metals. This makes them suitable for ornaments.
Metals and Non-metals Class 7 Important Questions on Properties
This section covers the properties students must learn carefully. Most exam questions from this chapter ask students to connect a property with a use.
Properties of Metals Class 7 Questions
Q1. What is malleability?
Malleability is the property by which a material can be beaten into thin sheets. Most metals are malleable.
Copper, aluminium and iron flatten when hammered. Coal and sulfur break into pieces, so they are brittle.
Q2. Give two examples of malleability in daily life.
Aluminium foil used for wrapping food shows malleability. Silver foil used on sweets also shows malleability.
Both are thin sheets made from metals. They form sheets because metals can be beaten without breaking easily.
Q3. What is ductility?
Ductility is the property by which a material can be drawn into wires. Metals generally show ductility.
Copper and aluminium wires are used in electrical fittings. Gold is highly ductile and can form very long wires.
Q4. Why are copper and aluminium used in electrical wiring?
Copper and aluminium are used in electrical wiring because they conduct electricity well. They are also ductile, so they can be drawn into wires.
This combination makes them useful in homes, appliances and electric circuits.
Q5. What is sonority?
Sonority is the property by which metals produce a ringing sound when struck. Metals are sonorous.
A school bell, metal plate, coin and ghungroos produce ringing sounds because of sonority. Wood and coal produce dull sounds.
Q6. Why are cooking vessels usually made of metals?
Cooking vessels are usually made of metals because metals conduct heat well. Heat passes quickly through the metal and cooks food.
The handles are often made of wood or plastic. These materials conduct heat poorly and protect hands from burns.
Q7. Why do electricians use tools with plastic or rubber handles?
Electricians use tools with plastic or rubber handles because these materials are poor conductors of electricity.
The metal part of a screwdriver can conduct electricity. The plastic handle reduces the risk of electric shock.
Class 7 Science Chapter 4 MCQ with Answers
Class 7 Science Chapter 4 MCQ questions test exact understanding of properties and examples. Read the options carefully because similar words can confuse students.
Q1. Which property allows metals to be beaten into sheets?
(a) Sonority
(b) Ductility
(c) Malleability
(d) Corrosion
Answer: (c) Malleability
Malleability allows metals to form thin sheets.
Q2. Which property allows metals to be drawn into wires?
(a) Ductility
(b) Brittleness
(c) Rusting
(d) Lustre
Answer: (a) Ductility
Ductility helps metals form wires.
Q3. Which material is sonorous?
(a) Coal
(b) Wood
(c) Metal coin
(d) Sulfur
Answer: (c) Metal coin
A metal coin gives a ringing sound when dropped.
Q4. Which metal is liquid at room temperature?
(a) Iron
(b) Mercury
(c) Aluminium
(d) Copper
Answer: (b) Mercury
Mercury is a metal found as a liquid at room temperature.
Q5. Which metal is stored in kerosene?
(a) Copper
(b) Sodium
(c) Aluminium
(d) Gold
Answer: (b) Sodium
Sodium reacts strongly with oxygen and water, so it is stored in kerosene.
Q6. Which condition is needed for rusting of iron?
(a) Dry air only
(b) Water only
(c) Both air and water
(d) Oil only
Answer: (c) Both air and water
Iron rusts when it comes in contact with moist air.
Q7. Magnesium oxide solution is:
(a) Acidic
(b) Basic
(c) Neutral
(d) Salty only
Answer: (b) Basic
Metal oxides are generally basic in nature.
Q8. Sulfur dioxide dissolved in water forms:
(a) A basic solution
(b) A neutral solution
(c) An acidic solution
(d) A metallic solution
Answer: (c) An acidic solution
Sulfur dioxide dissolves in water to form sulfurous acid.
Class 7 Science Chapter 4 Question Answer on Rusting and Corrosion
Rusting and corrosion questions are important because they test experiment-based reasoning. Students should clearly mention air, water and moist conditions.
Rusting of Iron Class 7 Questions
Q1. What is rusting?
Rusting is the process in which iron develops a brown deposit when exposed to moist air.
The brown deposit is called rust. Rusting damages iron objects over time.
Q2. What conditions are necessary for rusting of iron?
Both air and water are necessary for rusting. Iron does not rust in dry air alone or in water without air.
The textbook activity with three bottles shows this clearly. The iron nail rusts only when it touches both air and water.
Q3. Why does an iron nail not rust in a bottle containing silica gel?
Silica gel keeps the air dry by removing moisture. Without water, rusting cannot take place.
So, the nail kept with silica gel does not form brown deposits.
Q4. Why does an iron nail dipped completely in boiled water with oil not rust?
Boiled water has very little dissolved air. The oil layer stops air from entering the water again.
Since the nail does not get both air and water together, rusting does not happen.
Corrosion Class 7 Science Questions
Q5. What is corrosion?
Corrosion is the gradual damage of metal surfaces due to air, water or other substances.
Rusting of iron is one example of corrosion. Green coating on copper and black coating on silver are also examples.
Q6. How can rusting of iron be prevented?
Rusting can be prevented by painting, oiling, greasing or applying a protective layer of zinc.
These methods stop air and moisture from touching the iron surface.
Metal Oxides and Non-metal Oxides Class 7 Questions
This section connects Chapter 4 with the earlier chapter on acidic, basic and neutral substances. Students should remember how oxides behave with indicators.
Q1. What happens when magnesium burns in air?
Magnesium burns with a dazzling white flame. It changes into a white powder called magnesium oxide.
Magnesium reacts with oxygen in the air to form magnesium oxide.
Q2. What is the nature of magnesium oxide solution?
Magnesium oxide solution is basic in nature. It turns red litmus paper blue.
This shows that metal oxides are generally basic in nature.
Q3. What happens when sulfur burns in air?
Sulfur burns in air and forms sulfur dioxide gas. When this gas dissolves in water, it forms sulfurous acid.
The solution turns blue litmus red. This shows its acidic nature.
Q4. What is the main difference between metal oxides and non-metal oxides?
Metal oxides are generally basic in nature. Magnesium oxide is one example.
Non-metal oxides are generally acidic in nature. Sulfur dioxide forms an acidic solution when dissolved in water.
Q5. Does sulfur react with water directly?
Sulfur does not react with water directly. When sulfur powder is placed in water, no reaction occurs.
However, sulfur reacts with oxygen when it burns. The gas formed can dissolve in water and make an acidic solution.
Properties of Non-metals Class 7 Important Questions
Non-metals are often explained through contrast with metals. Students should avoid writing that every dull material is a non-metal.
Q1. What are the general properties of non-metals?
Non-metals are generally dull, soft or brittle, non-malleable, non-ductile and non-sonorous.
They are also poor conductors of heat and electricity. Sulfur, carbon, oxygen and nitrogen are examples.
Q2. Why are coal and sulfur called brittle?
Coal and sulfur are called brittle because they break into pieces when hammered.
They do not flatten like metals. This shows that they are not malleable.
Q3. Why can coal and sulfur not be drawn into wires?
Coal and sulfur are not ductile. They break instead of stretching into wires.
This is why we do not see wires made of coal or sulfur.
Q4. Why are plastic, glass, wood and rubber not called non-metals in this chapter?
Plastic, glass, wood and rubber are materials, but they are not elements. Metals and non-metals are categories of elements.
An element is a substance that cannot be broken down into simpler substances. Students study elements in detail in higher classes.
Q5. Why are non-metals important in everyday life?
Non-metals are essential for life and daily needs. Oxygen supports respiration. Carbon forms the base of living organisms.
Nitrogen helps in fertilisers. Chlorine helps in water purification. Iodine solution is used on wounds as an antiseptic.
Class 7 Science Chapter 4 Extra Questions and Answers
Class 7 Science Chapter 4 extra questions and answers help students prepare for application-based exams. They connect properties with uses.
Q1. Why is aluminium used for food wrapping foil?
Aluminium is malleable, so it can form thin sheets. These sheets fold easily around food.
It is also light and useful for packaging. That is why aluminium foil is common in kitchens.
Q2. Why are steel ropes used in bridges and cranes?
Steel ropes are strong and made from metal wires. Metals are ductile, so they can form wires.
These wires can support heavy loads. That is why steel ropes are used in suspension bridges and cranes.
Q3. Why does a metal spoon become hot in a glass of hot water?
A metal spoon becomes hot because metals conduct heat well. Heat travels from the hot water through the spoon.
A wooden spoon does not become as hot because wood is a poor conductor of heat.
Q4. Why can sulfur not be used instead of zinc to protect iron from rusting?
Sulfur cannot be used like zinc because it is a non-metal and does not form a protective metallic coating.
Zinc forms a protective layer over iron during galvanisation. Sulfur does not provide the same protection.
Q5. Why is sodium stored in kerosene?
Sodium is stored in kerosene because it reacts vigorously with oxygen and water. The reaction releases a lot of heat.
Kerosene prevents sodium from touching air and moisture. This keeps it safe.
Q6. Why is oxygen considered an important non-metal?
Oxygen is important because living organisms need it for respiration. Without oxygen, humans and animals cannot survive.
It also reacts with many substances. For example, magnesium burns in oxygen to form magnesium oxide.
Activity-Based Questions from The World of Metals and Non-metals Class 7
Activity-based questions need observation plus conclusion. Students should write both parts to score well.
Q1. A student hammers copper, aluminium, coal and sulfur. Copper and aluminium flatten, but coal and sulfur break. What does this show?
This shows that copper and aluminium are malleable metals. They can be beaten into sheets.
Coal and sulfur are brittle non-metals. They break into pieces when hammered.
Q2. A metal coin and a wooden block are dropped from the same height. What sound will they produce?
The metal coin will produce a ringing sound. This shows sonority.
The wooden block will produce a dull sound. Wood is not sonorous.
Q3. A bulb glows when copper wire is placed in a tester circuit. What does this prove?
This proves that copper conducts electricity. It allows electric current to pass through it.
Metals like copper, aluminium and iron are good conductors of electricity.
Q4. A bulb does not glow when rubber is placed in a tester circuit. Why?
Rubber is a poor conductor of electricity. It does not allow current to pass through easily.
This is why rubber is used in gloves and protective coverings.
Q5. An iron nail develops brown deposits only in one bottle where both air and water are present. What is the conclusion?
The conclusion is that both air and water are needed for rusting.
The brown deposit is rust. Rusting occurs when iron stays in moist air.
Competency-Based Questions on Metals and Non-metals Class 7
These questions test whether students can apply chapter ideas to new situations. Write the property first, then explain the use.
Q1. A student wants to make a cooking pan. Should the main body be made of aluminium or wood? Why?
The main body should be made of aluminium because aluminium conducts heat well.
Wood is a poor conductor of heat. It is better for the handle, not the cooking surface.
Q2. A bell maker chooses metal instead of rubber. Which property explains this choice?
The property is sonority. Metals produce a ringing sound when struck.
Rubber gives a dull sound. So, it is not suitable for making bells.
Q3. A farmer’s iron tools rust faster during the rainy season. Why?
Iron tools rust faster because rainy weather provides moisture.
Rusting needs both air and water. Moist air helps rust form on iron surfaces.
Q4. A student says all shiny objects are metals. Is this correct?
No, this is not always correct. Some non-metallic or coated objects may look shiny.
Students should test more properties such as malleability, ductility, sonority and conduction before deciding.
Q5. A wire must conduct electricity and bend easily. Which metal property matters here?
Ductility and electrical conductivity matter here.
Ductility helps the metal form wires. Electrical conductivity allows current to pass through the wire.
Long Answer Questions from Class 7 Science Chapter 4
Long answers should connect properties, observations and uses. Use examples from the chapter.
Q1. Explain the main properties of metals with examples.
Metals are generally hard and lustrous. Copper, aluminium and iron show metallic lustre when their surface is clean.
Metals are malleable. This means they can be beaten into sheets. Aluminium foil and silver foil are examples.
Metals are ductile. This means they can be drawn into wires. Copper and aluminium wires are used in electrical fittings.
Metals are sonorous. They produce a ringing sound when struck. School bells and metal coins show sonority.
Metals conduct heat and electricity well. This is why cooking vessels use metals and electric wires use copper or aluminium.
Q2. Explain the rusting experiment with three bottles.
In bottle A, an iron nail is kept with silica gel. Silica gel keeps air dry. The nail does not rust because water is absent.
In bottle B, an iron nail is dipped in boiled water with an oil layer above it. Boiling removes dissolved air, and oil prevents air from entering. The nail does not rust because air is absent.
In bottle C, an iron nail is partly dipped in water and exposed to air. The nail develops brown deposits.
This proves that rusting needs both air and water. The brown deposit formed on iron is called rust.
Q3. Compare the behaviour of magnesium and sulfur when burnt in air.
Magnesium is a metal. When it burns in air, it produces a dazzling white flame and forms magnesium oxide.
Magnesium oxide dissolves in water to form a basic solution. It turns red litmus blue.
Sulfur is a non-metal. When sulfur burns in air, it forms sulfur dioxide gas.
Sulfur dioxide dissolves in water to form sulfurous acid. The solution is acidic and turns blue litmus red.
This shows that metal oxides are generally basic, while non-metal oxides are generally acidic.
Q4. How do the properties of metals decide their uses?
The properties of metals decide where we use them. Their malleability helps make sheets, foils and utensils.
Their ductility helps make wires, ornaments and steel ropes. Their sonority helps make bells and musical instruments.
Their heat conduction helps make cooking vessels. Their electrical conduction helps make electric wires.
Their strength helps make tools, farming equipment, bridges and machines. This is why metals play an important role in daily life.
Q5. Why are non-metals essential even though they do not behave like metals?
Non-metals may not be malleable, ductile or sonorous, but they are essential for life.
Oxygen is needed for respiration. Carbon forms the base of proteins, fats and carbohydrates.
Nitrogen helps plants grow because it forms part of fertilisers. Chlorine is used in water purification.
Iodine solution works as an antiseptic on wounds. This shows that non-metals have important uses in health, agriculture and daily life.