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Important Questions for CBSE Class 10 Science Chapter 3 - Metals and Non-metals 2024-25

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Last updated date: 23rd Jul 2024
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CBSE Class 10 Science Chapter-3 Important Questions with Answers - Free PDF Download

The important questions on CBSE Class 10 Science Chapter 3 - Metals and Non-metals have been curated by our expert teachers in a manner that will allow students to explore the different kinds of problems that can be looked into based on the topics under this chapter. Students will get good practice before their exams and will be able to solve most of the problems related to the chapter. The questions and their answers are easy to comprehend and even easier to remember. These questions are most likely to be asked in their Class 10 Science exam since they follow the strict CBSE guidelines and are absolutely aligned with the Class 10 Science syllabus.


Here we discuss the third chapter of science, metals and mon-metals. The chapter discusses different types of metals, non-metals, their differences, reactions with other elements, symbols, and position on the periodic table. important questions for class 10 science chapter 3 metals and non-metals will easily get through the exam.

 

Vedantu is a platform that provides free CBSE Solutions (NCERT) and other study materials for students. You can download Class 10 Science and  Class 10 Maths NCERT Solutions to help you to revise the complete syllabus and score more marks in your examinations.


Download CBSE Class 10 Science Important Questions 2024-25 PDF

Also, check CBSE Class 10 Science Important Questions for other chapters:

CBSE Class 10 Science Important Questions

Sl.No

Chapter No

Chapter Name

1

Chapter 1

Chemical Reactions and Equations

2

Chapter 2

Acids, Bases and Salts

3

Chapter 3

Metals and Non-metals

4

Chapter 4

Carbon and Its Compounds

5

Chapter 5

Periodic Classification of Elements

6

Chapter 6

Life Processes

7

Chapter 7

Control and Coordination

8

Chapter 8

How do Organisms Reproduce?

9

Chapter 9

Heredity and Evolution

10

Chapter 10

Light Reflection and Refraction

11

Chapter 11

Human Eye and Colourful World

12

Chapter 12

Electricity

13

Chapter 13

Magnetic Effects of Electric Current

14

Chapter 14

Sources of Energy

15

Chapter 15

Our Environment

16

Chapter 16

Management of Natural Resources

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Important Topics under CBSE Class 10 Science Chapter 3 - Metals and Non-metals

Following are the important topics that are covered under the chapter on Metals and Non-metals:

  • What are Metals?

  • What are Non-metals?

  • Properties of Metals

  • Properties of Non-metals

  • Difference between Metals and Nonmetals


Study Important Questions for Class 10 Science Chapter 3 – Metals and Non-Metals

Very Short Answer Questions (1 Mark)

1. A mineral is known as ore if metal

  1. Cannot be produced from it

  2. Can be produced from it

  3. Can be extracted from it profitably

  4. Is very costly

Ans: (c) Can be extracted from it profitably


2. The earthy impurities associated with minerals used in metallurgy are called

  1. Slag

  2. Flux

  3. Gangue

  4. Ore

Ans: (c) Gangue


3. A basic lining is given to a furnace by using

  1. Calcined dolomite

  2. Copper sulphate

  3. Haematite

  4. Silica

Ans: (a) Calcined dolomite


4. Malachite is an ore of:

  1. Iron

  2. Copper

  3. Mercury

  4. Zinc

Ans: (b) Copper


5. Metal always found in free state is:

  1. Gold

  2. Silver

  3. Copper

  4. Sodium

Ans: (a) Gold


6. A process employed for the concentration of sulphide ore is

  1. Froth floatation

  2. Roasting

  3. Electrolysis

  4. Bessemerisation

Ans: (a) Froth floatation


7. The slag obtained during the extraction of copper pyrites is composed mainly of

  1. \[C{{u}_{2}}S\]

  2. $FeSi{{O}_{3}}$

  3. $CuSi{{O}_{3}}$

  4. $Si{{O}_{2}}$

Ans: (b) $FeSi{{O}_{3}}$


8. The common method for extraction of metals from the oxide ore is

  1. Reduction with carbon

  2. Reduction with hydrogen

  3. Reduction with aluminium

  4. Electrolytic method

Ans: (a) Reduction with carbon


9. An iron nail was suspended in $CuS{{O}_{4}}$ solution and kept for a while the solution is

  1. Remained blue and coating was found on the nail.

  2. Turned green and a coating was formed on the nail

  3. Remained blue and no coating was formed on the nail

  4. Turned green and no coating was formed on the nail

Ans: (b) Turned green and a coating was formed on the nail


10. The sulphide ore among the following is

  1. Haematite

  2. Bauxite

  3. Argentite

  4. Zinc blende

Ans: (d) Zinc blende


11. Chemically rust is

  1. Hydrated ferrous oxide

  2. Hydrated ferric oxide

  3. Only ferric oxide

  4. None of these

Ans: (b) Hydrated ferric oxide


12. Heating pyrites to remove sulphur is called

  1. Smelting

  2. Calcination

  3. Liquation

  4. Roasting

Ans: (d) Roasting


13. Setting of Plaster of Paris takes place due to

  1. Oxidation

  2. Reduction

  3. Dehydration

  4. Hydration

Ans: (d) Hydration


14. Some crystals of $CuS{{O}_{4}}$ were dissolved in water. The color of the solution obtained would be

  1. Green

  2. Red

  3. Blue

  4. Brown

Ans: (c) Blue


15. Most abundant metal on the surface of the earth

  1. Iron

  2. Aluminium

  3. Calcium

  4. Sodium

Ans: (b) Aluminium


16. Zone refining is used for the

  1. Concentration of an ore

  2. Reduction of metal oxide

  3. Purification of metal

  4. Purification of an ore

Ans: (c) Purification of metal


17. Which of the following processes is used for the concentration of Bauxite $(A{{l}_{2}}{{O}_{3}}.2{{H}_{2}}O)$

  1. Froth floatation

  2. Leaching

  3. Liquation

  4. Magnetic separation

Ans: (b) Leaching


18. During smelting, an additional substance is added which combines with impurities to form a fusible product. It is known as – 

  1. Slag

  2. Mud

  3. Gangue

  4. Flux

Ans: (d) Flux


19. The luster of a metal is due to

  1. Its high density

  2. Its high polishing

  3. Its chemical inertness

  4. Presence of free electrons.

Ans: (d) Presence of free electrons.


20. In the thermite process, the reducing agent is

  1. Nickel

  2. Zinc

  3. Sodium

  4. Aluminium

Ans: (d) Aluminium


21. In addition to iron, stainless steel contains:

  1. Nickel and Chromium

  2. Copper and Tin

  3. Aluminium and Magnesium

  4. Carbon and Magnesium

Ans: (a) Nickel and Chromium


22. The correct decreasing order of the metals in the activity series is:

  1. $Ca,Mg,Ni,Fe$

  2. $Ni,Ca,Mg,Fe$

  3. $Ca,Mg,Fe,Ni$

  4. $Mg,Ca,Fe,Ni$

Ans: (c) $Ca,Mg,Fe,Ni$


23. Which of the following oxides is amphoteric in nature?

  1. $N{{a}_{2}}O$

  2. $MgO$

  3. $CaO$

  4. $A{{l}_{2}}{{O}_{3}}$

Ans: (d) $A{{l}_{2}}{{O}_{3}}$


24. A student adds one big iron nail each in four test tubes containing a solution of zinc sulphate, aluminium sulphate, copper sulphate, and iron sulphate. A reddish-brown coating was observed only on the surface of the iron nail which was added in the solution of:

  1. Zinc Sulphate

  2. Iron Sulphate

  3. Copper Sulphate

  4. Aluminium Sulphate

Ans: (c) Copper Sulphate


25. An iron nail was kept in a solution kept in a test tube. After half an hour it was observed that the color of the solution was changed. The solution in the test tube was that of:

  1. Zinc Sulphate

  2. Iron Sulphate

  3. Copper Sulphate

  4. Aluminium Sulphate

Ans: (c) Copper Sulphate


26. Name two metals that are found in nature in the free state.

Ans: Gold and Platinum


27. What chemical process is used for obtaining a metal from its oxide?

Ans: The chemical process that is used for obtaining a metal from its oxide is called reduction. Here, the oxide of the metal will be reduced to the metal with the help of reducing agents or with substitution reactions with another highly reactive metal.


28. Which of the following pairs will give displacement reactions?

  1. $NaCl$ solution and copper metal

  2. $MgC{{l}_{2}}$ solution and aluminum metal

  3. $FeS{{O}_{4}}$ solution and silver metal

  4. $AgN{{O}_{3}}$ solution and copper metal

Ans: $AgN{{O}_{3}}$ solution and copper metal


29. Which of the following method is suitable for preventing an iron fry pan from rusting?

  1. Applying grease

  2. Applying paint

  3. Applying a coating of zinc

  4. All of the above

Ans: (c) Applying a coating of zinc


30. An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be

  1. Calcium

  2. Carbon

  3. Silicon

  4. Iron

Ans: (a) Calcium


31. Food cans are coated with tin and not zinc because

  1. Zinc is costlier than tin

  2. Zinc has higher melting point

  3. Zinc is more reactive than tin

  4. Zinc is less reactive than tin

Ans: (c) Zinc is more reactive than tin


32. What types of oxides are formed when non-metals combine with oxygen?

Ans: When non-metals combine with oxygen they result in the formation of acidic oxides.


33. Royal water is prepared by mixing two acids ‘A’ and ‘B’. It can dissolve gold and platinum. It is a highly corrosive and fuming liquid. Identify ‘A’ and ‘B’. What is the ratio in which ‘A’ and ‘B’ are mixed?

Ans: Acid ‘A’ is Hydrochloric Acid $(HCl)$ and acid ‘B’ is Nitric Acid $(HN{{O}_{3}})$. The ratio in which ‘A’$(HCl)$and ‘B’$(HN{{O}_{3}})$ are mixed is $3:1$.


Short Answer Questions (2 Marks)

1. Which gas is produced when a metal reacts with dilute hydrochloric acid? Write the chemical reaction when iron reacts with dilute ${{H}_{2}}S{{O}_{4}}$.

Ans: When a metal reacts with dilute hydrochloric acid, hydrogen gas $({{H}_{2}})$ is produced.

The chemical reaction when iron reacts with dilute ${{H}_{2}}S{{O}_{4}}$ is as follows:

$Fe(s)+2HCl(dil)\to FeC{{l}_{2}}(aq)+{{H}_{2}}(g)$

This reaction involves the formation of ferric chloride salt $(FeC{{l}_{2}})$ and the liberation of hydrogen gas $({{H}_{2}})$.


2. What would you observe when Zinc is added to a solution of Iron (II) sulphate? Write chemical reaction that takes place.

Ans: When Zinc is added to a solution of Iron (II) sulphate, the color of the solution changes from green to colorless. This happens because, zinc being more reactive than iron, displaces iron from iron sulphate and form the colorless zinc sulphate solution, and the iron gets precipitated at the bottom, in the form of a grey-colored precipitate.

The chemical reaction when Zinc is added to a solution of Iron (II) sulphate is:

$Zn(s)+FeS{{O}_{4}}(aq)\to ZnS{{O}_{4}}(aq)+Fe(s)\downarrow $


3. Why do ionic compounds have high melting points?

Ans: 

  • Ionic compounds have a high melting point because of the strong forces of attraction between the oppositely charged cations and anions. 

  • Typically, ionic compounds have an equal number of cations and anions that are tightly packed and arranged in a three-dimensional lattice to form their crystalline structures, which also attributes to their high melting points.


4. Why sodium is kept immersed in kerosene oil?

Ans: Sodium is highly reactive in nature. It reacts vigorously with both air and water and burns. So it is kept immersed in kerosene oil to avoid contact with air and water.


5. State two ways to prevent the rusting of iron.

Ans: 

(i). By coating the surface of iron with oil, grease, or paint

(ii). By depositing a layer of zinc on the surface of iron, through the process of galvanization.


6. What type of oxide ore is formed when non-metals combine with oxygen?

Ans: The type of oxide formed when non-metals combine with oxygen is acidic in nature. When these oxides are dissolved in water, the resulting solution turns blue litmus red. 

Example – $C+{{O}_{2}}\xrightarrow{heat}C{{O}_{2}}$


7. What are amphoteric oxides? Give examples?

Ans: Amphoteric oxides are oxides that behave as both acidic and basic oxides. They can neutralize both acids and bases. 

They undergo neutralization reaction to form water and salt when reacting with acid and form complex salts and water when reacting with base.

Examples – Aluminium oxide $(A{{l}_{2}}{{O}_{3}})$ and Zinc Oxide $(ZnO)$


8. Name two metals that can displace hydrogen from dilute acids and two metals which cannot do so?

Ans: 

  • Metals that can displace hydrogen from dilute acids are Sodium and Calcium.

  • Metals that cannot displace hydrogen from dilute acids are Copper and Silver.


9. Give the reason why platinum, gold, and silver are used to make jewelry.

Ans: 

  • Platinum, gold, and silver are used to make jewelry due to their low reactivity. These metals are placed at the bottom of the activity series and are also called noble metals. 

  • They do not corrode when exposed to air, water, or chemicals. Thus they do not lose their shine and have a bright luster, which makes them suitable for making jewelry. 

  • These metals are also highly malleable and ductile, so they can be shaped and designed as required. 


10. Why copper is used to make hot water tanks and not steel?

Ans: Copper is used to make hot water tanks, rather than steel because it is a good conductor of heat than steel. Also copper does not react with cold or hot water, or even with steam, while the iron component of steel (steel is an alloy of iron), reacts with steam and forms ferrous oxide. This makes the steel tank weak. Thus copper is used to make hot water tanks and not steel.


11. Can all minerals of a metal act as ores? Justify.

Ans: Ores are minerals that have a higher concentration of certain elements, while a mineral is a naturally occurring inorganic solid with definite chemical composition and crystalline structure.

A mineral can be considered as an ore when a metal can be extracted commercially from that mineral. But not all minerals are ores, because they can contain unwanted substances as well. Thus we can say that all ores are minerals, but not all minerals are ores.


12. How does Galvanization check rusting of iron?

Ans: Galvanization is the method of coating the surface of the iron with a thin layer of zinc preventing iron from coming in contact with moisture. 

In the activity series zinc lies above iron, so it acts as a sacrificial metal, i.e. it oxidizes instead of iron when exposed to the moisture, thus prevents iron from rusting.


13. Metals are arranged in the reactivity series. Why hydrogen is kept in the series though it is not a metal?

Ans: Hydrogen being a non-metal is placed in the reactivity series because its reactivity is similar to that of an electropositive element, say metals i.e. can lose electrons to form positive ions. Since hydrogen has one electron in its valance shell, it can lose its electron and become electropositive $({{H}^{+}})$.


14. Why are metals generally lustrous?

Ans: Metals are generally lustrous because of the flow of free electrons. These electrons can move freely through the metal, which can absorb the photons from light falling on their surface. After absorption, these electrons then release the energy as light, making the metal lustrous.

Also, the free electrons can reflect the light falling on them in the form of diffuse reflection, making the metal surface appear shiny. 


15. Corrosion of metals is not always harmful. Illustrate.

Ans: Corrosion of metals is a harmful process that results in the destruction of metal. But in certain cases, corrosion is actually advantageous.

Consider the case of corrosion of aluminium. When aluminium corrodes, it forms a layer of aluminium oxide \[(A{{l}_{2}}{{O}_{3}})\] over the metal. This oxide layer deposited on its surface acts as a protective coating and prevents further corrosion of the metal from the attacks of water, air, acids, or alkalis.


16. Why does copper not liberate hydrogen on reacting with dilute sulphuric acid?

Ans: Copper does not liberate hydrogen on reaching with dilute sulphuric acid because copper lies below hydrogen in the activity series. Due to this, copper cannot displace hydrogen from the acid, i.e. it cannot lose electrons to ${{H}^{+}}$ions and liberate hydrogen gas as other metals do.


17. Why are non-metals gaseous at room temperature?

Ans: The reason why non-metals are gaseous at room temperature is because of their mostly filled electronic structure. In their molecular form, non-metals exist as monoatomic or diatomic molecules like ${{H}_{2}},{{O}_{2}},{{N}_{2}},C{{l}_{2}},C{{O}_{2}}$, etc. Their atoms are covalently bonded in a molecule, while the intermolecular forces of attraction are weak that can be easily overcome at room temperature. Therefore, they exist as gases at room temperature.


18. Both calcium and magnesium are heavier than water but still float over them. Explain.

Ans: The density of Calcium is $1.74g/cc$ and that of Magnesium is $1.55g/cc$ while the density of water is $1.0g/cc$ at room temperature. And yet, both metals float over the water surface. It is because they react with water to produce metal-hydroxide, $Ca{{(OH)}_{2}},Mg{{(OH)}_{2}}$ respectively, and hydrogen gas $({{H}_{2}})$. The hydrogen gas, in the form of bubbles, sticks on the metal surface and makes them float above water. 


19. What is thermit reaction?

Ans: Thermit reactions are highly exothermic displacement reactions between a metal and metal oxide. The heat released in this exothermic reaction is so large, that the metal is obtained in its molten state.

The most common thermit reaction is between ferric oxide with aluminium metal, which is used to join railway tracks or cracked machine parts.

Reaction – $F{{e}_{2}}{{O}_{3}}(s)+2Al(s)\xrightarrow{heat}2Fe(l)+A{{l}_{2}}{{O}_{3}}(s)+heat$


20. Write the equation for the reaction of

(i). Iron with steam

(ii). Calcium and potassium with water

Ans: 

(i). Iron with steam – $3Fe+4{{H}_{2}}O\to F{{e}_{3}}{{O}_{4}}+{{H}_{2}}$

(ii). Calcium with water – \[Ca+2{{H}_{2}}O\to Ca{{(OH)}_{2}}+{{H}_{2}}\]

       Potassium with water – \[2K+2{{H}_{2}}O\to 2KOH+{{H}_{2}}\]


21. Which gas is produced when dilute hydrochloric acid is added to reactive metal?

Ans: Hydrogen gas is produced when dilute hydrochloric acid is added to a reactive metal.

Example – Iron reacts with dilute hydrochloric acid to produce iron sulphate and hydrogen gas.

$Fe+2HCl\to FeC{{l}_{2}}+{{H}_{2}}\uparrow $


22. Which metals do not corrode easily?

Ans: Noble metals which are at the bottom of activity series like silver, gold, and platinum do not corrode easily.


23. What are alloys?

Ans: An alloy is a homogeneous mixture of two or more metals, or a metal and a nonmetal. It is prepared by first melting the primary metal, and then, dissolving the other elements in it in definite proportions. It is then cooled to room temperature.

Examples – Brass is an alloy of copper and zinc (Cu and Zn), and bronze is an alloy of copper and tin (Cu and Sn).


24. In the electrolytic refining of a metal M, what would you take as the anode, the cathode, and the electrolyte?

Ans: 

  • Anode – a rod of impure metal M.

  • Cathode – thin strips of pure metal M.

  • Electrolyte – the salt solution of metal M.


25. Metal acts as a good reducing agent. It reduces $F{{e}_{2}}{{O}_{3}}$and $Mn{{O}_{2}}$. The reaction with $F{{e}_{2}}{{O}_{3}}$ is used for welding broke railway tracks. Identify & the metal and write all the chemical reactions.

Ans: The metal that acts as a good reducing agent, reducing $F{{e}_{2}}{{O}_{3}}$and $Mn{{O}_{2}}$ is Aluminum.

The thermite reaction between ferric oxide $F{{e}_{2}}{{O}_{3}}$ with aluminium metal is used for welding broke railway tracks.

Reactions – 

$F{{e}_{2}}{{O}_{3}}(s)+2Al(s)\xrightarrow{heat}2Fe(l)+A{{l}_{2}}{{O}_{3}}(s)+heat$

$3Mn{{O}_{2}}(s)+4Al(s)\xrightarrow{heat}Mn(l)+2A{{l}_{2}}{{O}_{3}}(s)+heat$


26. A yellow-colored powder ‘X’ is soluble in carbon disulfide. It burns with a blue flame, forming suffocating smelling gas which turns moist blue litmus red. Identify ‘X’ and gives a chemical reaction. Identify whether it is a metal or non-metal.

Ans: The yellow-colored powder ‘X’ is sulfur.

Sulfur is soluble in carbon disulfide.

Sulfur burns in oxygen with a blue flame to form sulfur dioxide, which has a suffocating smell.

Reaction – $S(s)+{{O}_{2}}(g)\to S{{O}_{2}}(g)$

$S{{O}_{2}}$ turns moist blue litmus red, as it is acidic in nature.

Sulfur is a non-metal.


27. A student set up an electric circuit as shown in Fig. He placed the metal to be tested in the circuit between terminals A and B as shown.

(Image will be uploaded soon)

(i). Does the bulb glow? What does this indicate?

(ii). Why are electric wires coated with rubber-like materials?

Ans: 

(i). Yes, the bulb glows when a metal is placed between terminals A and B. This indicates that metal is a good conductor of electricity.

(ii). Electric wires are coated with rubber-like materials because rubber is a poor conductor of electricity/ it acts as an insulator, which protects the person from getting electric shock due to current flow.


28. A, B and C are 3 elements that undergo chemical reactions according to the following equations:

(a) ${{A}_{2}}{{O}_{3}}+2B\to {{B}_{2}}{{O}_{3}}+2A$

(b) $3CS{{O}_{4}}+2B\to {{B}_{2}}{{(S{{O}_{4}})}_{3}}+3C$

(c) $3CO+2A\to {{A}_{2}}{{O}_{3}}+3C$

The answer of the following:

(i). Which element is most reactive?

(ii). Which element is least reactive?

Ans: Hint – a more reactive element will replace a lesser reactive element.

(i). From reactions (a) and (b), we can say that the most reactive element is B because it can replace both A and C from their compounds.

(ii). From reactions (b) and (c), we can say that element C is the least reactive as it has been replaced both by A and B.


29. An element X on reacting with ${{O}_{2}}$ forms the oxide$(X{{O}_{2}})$. This oxide dissolves in water and turns blue litmus paper red. Predict the nature of the element whether it is a metal or a non-metal.

Ans: The oxide is acidic in nature because it turns blue litmus to red. 

Thus element X is a non-metal.


30. An element E combines with ${{O}_{2}}$ to form an oxide${{E}_{2}}O$, which is a good conductor of electricity. Answer the following:

(i). How many electrons will be present in the outermost shell of E?

(ii). Write the formula of the compound formed when it combines with Chlorine.

Ans:

(i) The number of electrons in the outermost shell of element E is $1$. Here, the valency of oxygen is $2$. Since the oxide formed is ${{E}_{2}}O$, it means that the valency of E is$1$, i.e. E has only one electron in the valence shell.

(ii) It is known that the valency of Chlorine is $1$and since the valency of E is also $1$, the resultant compound is $ECl$.

Reaction – ${{E}^{+}}+C{{l}^{-}}\to ECl$


Short Answer Questions (3 Marks)

1. Arrange the following metals in decreasing order of their reactivity:

(1) $Cu,Ca,Mg,Na,Zn$

(2) You are provided with three metals: sodium, magnesium, and copper. Using only water as the reactant, how will you identify each of them?

(3) Which metal listed in (1) is most likely to occur in the native state?

Ans: 

(1) The decreasing order of reactivity is – Na > Ca > Mg > Zn > Cu

(2) With water as the only reactant we can distinguish Sodium, Magnesium, and Copper:

  1. Sodium reacts vigorously with cold water and burns.

  2. Magnesium is not reactive with cold water, but reacts with hot water and produces hydrogen gas bubbles, and floats to the surface.

  3. Copper remains unaffected or unreactive with neither cold nor hot water.

(3) Copper metal is the one that is most likely to occur in the native state, because it is at the bottom of the activity series, meaning it is least reactive.


2. Which method of concentration of ore is preferred in the following cases and why?

(1) The ore has higher density particles mixed with a large bulk of low-density impurities.

(2) The ore consists of copper sulphide intermixed with clay particles.

(3) Give an example of amalgam.

Ans: 

(1) The concentration of ore can be done by gravity separation method or hydraulic washing, because of the difference in densities, the low-density impurities can be washed away, while the high-density ore particles would settle down.

(2) The concentration of ore is done by the froth floatation process because of the difference in the wetting characteristic of the metal and clay particles with oil and water.

(3) An alloy, with one of the metals as mercury, is called amalgam. An example of amalgam is the mixture of mercury with silver which is used to fill dental cavities.


3. 

(a) Why is $ZnO$ called an amphoteric oxide? Name another amphoteric oxide.

(b) What are alkalis? Give one example of alkali.

Ans: 

(a) Amphoteric oxides are oxides that behave as both acidic and basic oxides. They can neutralize both acids and bases. 

They undergo neutralization reaction to form water and salt when reacting with acid and form complex salts and water when reacting with base.

Zinc oxide (ZnO) is an amphoteric oxide because it behaves both as acidic and basic oxide.

Reaction:

As acidic oxide – 

$ ZnO(s)+2NaOH(aq)\to N{{a}_{2}}Zn{{O}_{2}}(aq)+{{H}_{2}}O(l) $

$ ZincOxide(acid)+SodiumHydroxide(alkali)\to SodiumZincate(salt)+water $

As basic oxide – 

$ ZnO(s)+2HCl(aq)\to ZnC{{l}_{2}}(aq)+{{H}_{2}}O(l) $

$ ZincOxide(alkali)+HydrochloricAcid(acid)\to ZincChloride(salt)+water $

(b) Alkalis are bases that are completely soluble in water or they are the water-soluble hydroxides of metals.

Examples – Sodium Hydroxide $(NaOH)$


4. You are given a hammer, a battery, a bulb, wires, and a switch.

(a) How could you use them to distinguish between samples of metals and non-metals?

(b) Assess the usefulness of these tests to distinguish between metals and non-metals.

Ans: 

(a) To distinguish between metals and non-metals – 

  • With a hammer: Checking for malleability.

By beating the sample with a hammer we can find if the sample is a metal or non-metal. Metals exhibit the property of malleability, where they can be beaten into thin sheets, while non-metals being brittle, tend to break.

  • With a battery, bulb, wires, and switch: Checking for conductivity. 

Set up the circuit below.

(Image will be uploaded soon)

By placing the sample between terminals A and B, we can find if the sample is metal or non-metal. Metals are good conductors of electricity, while non-metals are not. So if by placing the sample between the terminals the bulb glows, it is a metal; if the bulb does not glow, then it is a non-metal. 

(b) These tests are useful in distinguishing between metals and non-metals:

  • Beating the sample with a hammer, we can check for its malleability, i.e. checking the physical property of the sample. Metals exhibit the property of malleability, where they can be beaten into thin sheets, while non-metals being brittle, tend to break.

  • Using an electric circuit we can check for the conductivity of the sample to determine whether it is a metal or a non-metal. Metals are good conductors of electricity, while non-metals are not.


5. Name an alloy of

(i). Aluminium is used in the construction of aircraft.

(ii). Lead is used in joining metals for electric work.

(iii). Copper is used in household vessels.

Ans:

(i). Duralumin is a strong, hard, lightweight alloy of aluminum that is widely used in aircraft construction.

Composition of Duralumin – $Al(95\%),Cu(4\%),Mg(0.5\%),Mn(0.5\%)$

(ii). Solder is an alloy of lead and tin that has a low melting point and is used for welding electrical wires together.

Composition of Solder – $Pb(50\%),Sn(50\%)$

(iii). Brass is an alloy of copper and zinc that is used for making household vessels.

Composition of Brass – $Cu(80\%),Zn(20\%)$


6. What are the three important properties of aluminium which are responsible for its great demand in the industry?

Ans: 

(i). Aluminium is a good conductor of electricity.

(ii). It is not attacked by water, i.e. it is resistant to corrosion.

(iii). It is a powerful reducing agent.

(iv). It is malleable and ductile.


7. Which of the following metals would give hydrogen when added to dilute HCl?

(1) Iron

(2) Copper 

(3) Magnesium

Ans: 

Iron and magnesium would liberate hydrogen gas on reacting with dilute HCl. These are active metals that are placed above hydrogen in the activity series. 

Reaction – 

$Fe+2HCl\to FeC{{l}_{2}}+{{H}_{2}}\uparrow $

$Mg+2HCl\to MgC{{l}_{2}}+{{H}_{2}}\uparrow $

Since copper is placed below hydrogen in the activity series, it has lower reactivity and will not evolve hydrogen gas when added to dilute HCl.

Reaction – 

\[Cu+HCl\to (No-reaction)\]


8. Define an alloy and an amalgam. State the main constituents of the following alloys – Stainless steel, Bronze. In which property, each of them is different from its main constituent?

Ans: 

  • An alloy is a homogeneous mixture of two or more metals, or a metal and a nonmetal. It is prepared by first melting the primary metal, and then, dissolving the other elements in it in definite proportions. It is then cooled to room temperature.

Examples of Alloys – Brass is an alloy of copper and zinc (Cu and Zn), and bronze is an alloy of copper and tin (Cu and Sn).

  • An alloy, with one of the metals as mercury, is called amalgam.

An example of amalgam is the mixture of mercury with silver which is used to fill dental cavities.

Main constituents of:

  • Stainless steel – Stainless steel is an alloy of iron, chromium, carbon, and nickel. It exhibits a higher level of resistance to corrosion by rust formation than compared to its major constituent iron.

  • Bronze – Bronze is an alloy of copper and tin (Cu and Sn). It has a lower electrical conductivity than its constituents and is less malleable than copper.


9. A group of students looked at different metals and metal sulphate solutions are given in a tabular form. From the data, answer the following:

Metal

Metal sulphate solution

Colour

  1. Chromium

Chromium sulphate

Green

  1. Cobalt

Cobalt sulphate

Pink

  1. Copper 

Copper sulphate 

Blue

  1. Magnesium 

Magnesium sulphate 

Colourless

(a) Which metal reacted with all other sulphate solutions?

(b) Which metal did not react with any other metal sulphate solution?

(c) Arrange the metals in decreasing order of reactivity.

Ans: 

(a) Magnesium (Mg) reacted with all other sulphate solutions.

(b) Copper (Cu) did not react with any other metal sulphate solution.

(c) The decreasing order of reactivity of metals is Mg > Cr > Co > Cu.


10. Choose the appropriate element from the following:

(1) A metal that gets covered with a protective film of its oxide (Al, Cu, Ag).

(2) A metal that burns in the air with golden flame (Zn, K, Na).

(3) A metal that can displace hydrogen from boiling water as well as steam (K, Zn, Fe).

Ans: 

(1) Aluminium (Al)

(2) Sodium (Na)

(3) Zinc (Zn)


11. Write one point of difference between electrolytic reduction and reduction with carbon. Give one example of each.

Ans: In the case of electrolytic reduction, electrolysis is used for reduction, i.e. the reduction takes place at the cathode by the gain of electrons during electrolysis. 

Example – 

$ NaCl(molten)\xrightarrow{electrolysis}N{{a}^{+}}+C{{l}^{-}} $

$ Cathode-N{{a}^{+}}+{{e}^{-}}\to Na(reduction) $

While reduction with carbon, carbon acts as the reducing agent, i.e. reduction is carried out by heating a metal oxide with coke.

Example – 

$ZnO+C(coke)\xrightarrow{heat}Zn+CO$


12. Write the equation for the reaction of

(a) Iron with steam.

(b) Calcium with water.

(c) Potassium with water.

Ans:  

  1. $3Fe(s)+4{{H}_{2}}O(g)\to F{{e}_{3}}{{O}_{4}}(s)+{{H}_{2}}(g)$

  2. $Ca(s)+2{{H}_{2}}O(l)\to Ca{{(OH)}_{2}}(aq)+{{H}_{2}}(g)$

  3. $2K(s)+2{{H}_{2}}O(l)\to 2KOH(aq)+{{H}_{2}}(g)+heat$


13. Define the following terms:

  1. Minerals

  2. Ores

  3. Gangue

Ans: 

(a) Minerals – Minerals are substances that are formed naturally on Earth. They are usually solid and inorganic with a crystal structure and are formed naturally by geological processes. These are combined states of metals with other materials like soil, sand, rocks, etc.

(b) Ores – Ores are minerals that have a higher concentration of a certain element. A mineral can be considered as an ore when a metal can be extracted commercially and profitably from that mineral.

(c) Gangue – Gangue is the earthy impurities such as mud, sand, clay, rock, or any other material that is associated with ores.


14. Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it. What will be the action of gas in –

(1) Dry litmus paper?

(2) Moist litmus paper?

Write a balanced chemical equation for the reaction taking place.

Ans: 

Sulfur burns in oxygen with a blue flame to form sulfur dioxide $S{{O}_{2}}$, which has a suffocating smell.

Balanced Chemical Equation – $S(s)+{{O}_{2}}(g)\to S{{O}_{2}}(g)$

(1) $S{{O}_{2}}$ with dry litmus paper – $S{{O}_{2}}$in its gaseous state does not change the color of dry litmus.

(2) $S{{O}_{2}}$ with moist litmus paper –$S{{O}_{2}}$ turns moist blue litmus red, as it forms sulfurous acid with water, which is acidic in nature.

Balanced Chemical Equation – $S{{O}_{2}}(g)+{{H}_{2}}O(aq)\to {{H}_{2}}S{{O}_{3}}(aq)$


15. Write any three differences between metals and non-metals on the basis of chemical properties?

Ans: 

Metals

Non-metals

They dissolve in mineral acids to form salt and liberate some gas.

They generally do not react with mineral acids.

They are good reducing agents.

They are good oxidizing agents.

Their oxides are basic in nature.

Their oxides are acidic in nature.

They usually form unstable hydrides.

They usually form stable hydrides.

They displace hydrogen from water (or steam).

They do not react with water (or steam).


16. Why is titanium metal called strategic metal? Mention two of its properties that make it so special.

Ans: Titanium metal is called strategic metal because it is used in the production of spacecraft, aircraft and missiles, and other war equipment.

Properties that make titanium special are:

(i) It is light in weight but at the same time stronger than the other metals.

(ii) It is not affected by corrosion even after being exposed to the atmosphere for a long duration. 


17.  

(a) What is corrosion?

(b) How is corrosion caused?

(c) Complete the reaction – $2Fe+\dfrac{3}{2}{{O}_{2}}+x{{H}_{2}}O\to $

Ans: 

(a) Corrosion is the process that causes damage to the metal, due to the eating up of the surface of the metal when kept exposed to air and moisture for a long time. It is a natural process that results in the transformation of pure metals into undesirable substances when they react with air and water.

(b) Corrosion is mainly caused by a chemical or electrochemical reaction of the metal with its environment that results in its gradual destruction. It converts the metal into a more chemically stable oxide or hydroxide or sulphide.

Example – Copper metal reacts with moist carbon dioxide in the air and results in the formation of a green coat of copper carbonate over the metal surface.

Reaction – 

$ 2Cu+{{H}_{2}}O+C{{O}_{2}}+{{O}_{2}}\to Cu{{(OH)}_{2}}.CuC{{O}_{3}} $

$ Copper+AtmosphericGases\to CopperCarbonate(green) $

(c) $2Fe+\dfrac{3}{2}{{O}_{2}}+x{{H}_{2}}O\to F{{e}_{2}}{{O}_{3}}.x{{H}_{2}}O$

Here, $F{{e}_{2}}{{O}_{3}}.x{{H}_{2}}O$ is hydrated ferric oxide, i.e. rust.


18. 

(1) Choose metal from the reactivity series which will not react with steam.

(2) Choose one metal that will safely react with dilute sulphuric acid.

(3) Name the salt formed when metal chosen in (2) reacts with sulphuric acid.

Ans:

(1) Gold (Au)

(2) Zinc (Zn)

(3) The salt formed is zinc sulphate $ZnS{{O}_{4}}$and it is colorless.


19. A copper plate was dipped into a solution of $AgN{{O}_{3}}$. After some time a black layer was deposited on the copper plate. State the reason for it. Write the chemical equation for the reaction involved.

Ans: When a copper plate is dipped in a solution of silver nitrate $AgN{{O}_{3}}$, a black layer of silver will be deposited over the copper plate. This is because copper is above silver in the activity series, meaning copper is more reactive than silver. Thus, a displacement reaction occurs between copper (more reactive) and silver (less reactive), that copper displaces silver from its solution $AgN{{O}_{3}}$ and forms copper nitrate $Cu{{(N{{O}_{3}})}_{2}}$. This results in the deposition of silver over the plate that can be seen as a black layer.

Reaction – $Cu(s)+2AgN{{O}_{3}}(aq)\to Cu{{(N{{O}_{3}})}_{2}}(aq)+2Ag(s)$


20. Give an example of metal which

(i). is a liquid at room temperature.

(ii). can be easily cut with a knife.

(iii). is the best conductor of heat.

(iv). is a poor conductor of heat.

Ans: 

(i). Mercury

(ii). Sodium

(iii). Silver

(iv). Lead


21. Explain the meaning of malleable and ductile.

Ans: 

  • Malleable – The ability of metals to be beaten into thin sheets is called malleability.

Example: Iron, Copper.

  • Ductile – The ability of metals to be drawn into thin wires is called ductility. 

Example: Gold, Silver.


22. 

(i). Write the electron-dot structures for sodium, oxygen, and magnesium.

(ii). Show the formation of $N{{a}_{2}}O$and $MgO$ by the transfer of electrons.

(iii). What are the ions present in these compounds?

Ans: 

(Image will be uploaded soon)

(iii) Ions present in $N{{a}_{2}}O$ are $N{{a}^{+}}$ and ${{O}^{2-}}$

Ions present in $MgO$ are $M{{g}^{2+}}$ and ${{O}^{2-}}$


23. Metallic oxides of zinc, magnesium, and copper were heated with the following metals:

Metal

Zinc

Magnesium

Copper

Zinc oxide




Magnesium oxide




Copper oxide




In which case will you find displacement reactions taking place?

Ans: Based on the activity series of metals, the displacement reactions will take place as below:

Metal

Zinc

Magnesium

Copper

Zinc oxide

No reaction

Displacement

No reaction

Magnesium oxide

No reaction

No reaction

No reaction

Copper oxide

Displacement

Displacement

No reaction


24. You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

Ans: Copper metal reacts with moist carbon dioxide in the air and results in the formation of a green coat of copper carbonate over the metal surface. Thus it loses its shiny brown appearance.

Reaction – 

$2Cu+{{H}_{2}}O+C{{O}_{2}}+{{O}_{2}}\to Cu{{(OH)}_{2}}.CuC{{O}_{3}} $

$ Copper+AtmosphericGases\to CopperCarbonate(green) $

To remove the green layer of copper carbonate, lemon juice or tamarind juice is used. The citric acid and/or tartaric acid present in these juices dissolves the copper carbonate and converts it into soluble copper citrate or copper tartrate, which can be easily removed from the surface and hence restoring the shiny brown appearance of copper.

 

25. A man went door to door posing as a goldsmith. He promised to bring back the glitter of the old and dull ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument, the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?

Ans: The man used the Aqua-regia solution, which is a $3:1$ ratio mixture of concentrated hydrochloric acid and concentrated nitric acid. This solution has the ability to dissolve gold. Thus, when the man dipped the gold bangles in this solution, it had dissolved a significant amount of gold from the bangles, which explains the drastic loss in weight of the bangles. But by dissolving the outer layer, the inner shiny layer appears that gives off the appearance that the bangles were cleaned.


26. Differentiate between metal and non-metal on the basis of their chemical properties.

Ans: The differences are: 

Metals

Non-metals

They dissolve in mineral acids to form salt and liberate some gas.

They generally do not react with mineral acids.

They are good reducing agents.

They are good oxidizing agents.

Their oxides are basic in nature.

Their oxides are acidic in nature.

They usually form unstable hydrides.

They usually form stable hydrides.

They displace hydrogen from water (or steam).

They do not react with water (or steam).


27. An element reacts with oxygen to form an oxide which dissolves in dilute hydrochloric acid. The oxide formed also turns a solution of red litmus blue. Is the element metal or non-metal? Explain with the help of a suitable example.

Ans: The element is metal because the oxides of metals are basic in nature, which can turn red litmus solution blue. Also since the oxide seems to have dissolved in dilute hydrochloric acid, this also suggests that the oxide is basic. 

Since metallic oxides are typically basic in nature, we can conclude that the element is a metal.

Example – Consider the metal to be Magnesium.

Reactions –

With oxygen to form an oxide: $2Mg(s)+{{O}_{2}}(g)\to 2MgO(s)$

Oxide dissolving in hydrochloric acid: $MgO(s)+2HCl(aq)\to MgC{{l}_{2}}(aq)+{{H}_{2}}O(l)$

In aqueous conditions, it forms a base that turns red litmus blue:$MgO(s)+{{H}_{2}}O(l)\to Mg{{(OH)}_{2}}$


28. Nikita took Zn, Al, Cu, Fe, Mg, and Na metals, and put each metal in cold water and then hot water. She then reacted the metal with steam.

(i) Name the metal which reacts with cold water.

(ii) Which of the above metals react with steam?

(iii) Name the metal which reacts with hot water

(iv) Arrange these metals in order of increasing reactivity

Ans: 

(i) Na

(ii) Zn, Al, Fe

(iii) Mg

(iv) Na > Mg > Al > Zn > Fe > Cu


29. A student was given Mg, Zn, Fe, and Cu metals. He put each of them in dilute HCl contained in different test tubes. Identify which of them

(i) will not displace ${{H}_{2}}$ from dilute HCl.

(ii) forms a pale green substance.

(iii) will give ${{H}_{2}}$ with 5% $HN{{O}_{3}}$.

(iv) will be displaced from its salt solution by all other metals.

Ans: 

(i) Cu, because it is less reactive than hydrogen in the activity series.

(ii) Fe, because it forms ferrous chloride in hydrochloric acid.

(iii) Mg gives off hydrogen gas upon reacting with nitric acid.

(iv) Cu, because it has lower activity than compared to the other three metals.


30. A metal ‘X’ is found in the form of filings which burns vigorously when sprinkled on flame. When these filings are treated with sulphur, a black-colored compound ‘Y’ is formed which is not attracted by a magnet. ‘X’ reacts with dilute HCl to liberate hydrogen gas. ‘X’ reacts with steam to form ‘Z’ along with hydrogen gas. Identify ‘X’, ‘Y’, and ‘Z’. Write the reactions involved.

Ans: We can say that X is a metal that can react with steam and with hydrochloric acid to liberate hydrogen gas. Since ‘X’ is magnetic but its sulphide is non-magnetic, we can say that ‘X’ is iron and ‘Y’ is iron sulphide.

When iron reacts with steam it forms ‘Z’, which is iron (ii, iii) oxide.

Reactions – 

Iron filings with sulphur: $Fe+S\to FeS$

Iron filings with hydrochloric acid: $Fe+2HCl\to FeC{{l}_{2}}+{{H}_{2}}$

Iron filings with steam: $3Fe+4{{H}_{2}}O\to F{{e}_{3}}{{O}_{4}}+4{{H}_{2}}$

Thus – X is$Fe$, Y is $FeS$ and Z is $F{{e}_{3}}{{O}_{4}}$.


Long Answer Questions (5 Marks)

1. 

(a) Name a metal that does not stick to glass?

(b) Name a non-metal which is a good conductor of electricity?

(c) Name the metal which is commonly used in thermit welding?

(d) What gets deposited at the cathode, a pure or impure metal?

(e) What is the nature of Zinc oxide?

Ans: 

(a) Mercury

(b) Graphite

(c) Aluminum

(d) A pure metal is always deposited at the cathode

(e) Zinc oxide (ZnO) is an amphoteric oxide.


2. Name three common forms in which metals occur in nature. Explain the interaction between metals and dilute acid?

Ans: The three common forms in which metals occur in nature are:

  • Sulphide form – e.g. copper pyrite $(CuFe{{S}_{2}})$

  • Oxide form – e.g. Bauxite $(A{{l}_{2}}{{O}_{3}}.2{{H}_{2}}O)$

  • Carbonate form – e.g. Calamine $(ZnC{{O}_{3}})$

Active metals generally interact with dilute hydrochloric acid or dilute sulphuric acid and liberate hydrogen gas. Also, those metals that are below hydrogen in the activity series neither liberate hydrogen gas nor react with the dilute acid.

Example reactions of metals with dilute hydrochloric acid –

$Fe+2HCl\to FeC{{l}_{2}}+{{H}_{2}}\uparrow $

$Mg+2HCl\to MgC{{l}_{2}}+{{H}_{2}}\uparrow $


3. Sample pieces of five metals A, B, C, D, and E were added to the tabulated solutions separately. The results observed are shown in the table:

Metal

$FeS{{O}_{4}}$

$CuS{{O}_{4}}$

$ZnS{{O}_{4}}$

$AgN{{O}_{3}}$

$A{{l}_{2}}{{(S{{O}_{4}})}_{3}}$

A

No Change

No Change

No Change

Coating on metal

No Change

B

Grey Deposit on metal

Brown coating on metal

No Change

Coating on metal

No Change

C

No Change

No Change

No Change

No Change

No Change

D

No Change

---

No Change

Coating on metal

No Change

E

---

Brown coating

New coating

New coating

No Change

Based on the observations recorded in the table, answer the following:

(1) Which is the most reactive metal?

(2) Which is the least reactive metal?

(3) What would be observed if metal D were added to a solution of copper (II) sulphate?

(4) What would be observed if metal E were added to a solution of iron (II) sulphate?

(5) Arrange the metals A, B, C, D, and E in decreasing order to their reactivity?

Ans: 

(1) E is the most reactive because it displaces almost all of the elements from their solutions

(2) C is the least reactive because it does not react with any of the solutions to undergo displacement.

(3) It is clear that D is more reactive than silver but less reactive than iron. Thus it can displace copper from $CuS{{O}_{4}}$

(4) Metal E is more reactive than zinc because it can displace zinc from its solution. Since iron is less reactive than zinc, we can conclude that E would displace iron from $FeS{{O}_{4}}$

(5) The decreasing order of reactivity – E > B > D > A > C.


4. Hydrogen gas is evolved by reacting a piece of magnesium ribbon with water:

(1) Describe how it could be shown that the gas collected is hydrogen.

(2) Write a chemical equation for the reaction taking place between magnesium and water using symbols.

(3) Suggest how the appearance of magnesium would change after a week.

(4) A few drops of universal indicator solution were added to water in the beaker. What color would expect to see and what pH would this color indicate?

Ans: 

(1) If a lighted splint is brought near the collected gas, it will burn very brightly, along with a ‘pop’ sound. This shows that the gas evolved by a magnesium ribbon upon its reaction with water is hydrogen.

(2) The chemical equation for the reaction is: $Mg(s)+2{{H}_{2}}O(l)\to Mg{{(OH)}_{2}}(aq)+{{H}_{2}}(g)\uparrow $

(3) After a week’s time, magnesium will lose all its shine and a deposit of magnesium hydroxide will be formed on the surface of the metal.

(4) The indicator will become blue, indicating that the solution is basic. The pH of the solution would be more than seven.


5. Samples of four metals A, B, C, and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows:

Metal

$FeS{{O}_{4}}$

$CuS{{O}_{4}}$

$ZnS{{O}_{4}}$

$AgN{{O}_{3}}$

A

No reaction

Displacement

---

---

B

Displacement

---

No reaction

---

C

No reaction

No reaction

No reaction

Displacement

D

No reaction

No reaction

No reaction

No reaction

Use the table given above to answer the following questions about metals A, B, C, and D.

(i). Which is the most reactive metal?

(ii). What would you observe if B is added to a solution of Copper(II) sulphate?

(iii). Arrange the metals A, B, C, and D in order of decreasing reactivity.

Ans:

(i). B is the most reactive metal because it displaces the iron from its solution, which is the most reactive of all the elements.

(ii). It is clear that B is more reactive than iron, and since copper is less reactive than iron, B can displace copper from $CuS{{O}_{4}}$.

(iii). The decreasing order of reactivity is B > A > C > D.


6. Give reasons:

(a) Platinum, gold, and silver are used to make jewelry.

(b) Sodium, potassium, and lithium are stored under oil.

(c) Aluminum is a highly reactive metal, yet it is used to make utensils for cooking.

(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.

Ans: 

(a) Platinum, gold, and silver are used to make jewelry due to their low reactivity. These metals are placed at the bottom of the activity series and are also called noble metals. They do not corrode when exposed to air, water, or chemicals. Thus they do not lose their shine and have a bright luster, which makes them suitable for making jewelry. These metals are also highly malleable and ductile, so they can be shaped and designed as required.

(b) Sodium, potassium, and lithium are highly reactive in nature. They can react vigorously with both air and water and burn. So they are kept immersed in oil to avoid contact with air and water.

(c) Aluminium, despite being a highly reactive metal is typically used to make cooking utensils because the corrosion of aluminium has an advantage. When aluminium corrodes, it forms a layer of aluminium oxide \[(A{{l}_{2}}{{O}_{3}})\] over the metal. This oxide layer deposited on its surface acts as a protective coating and prevents further corrosion of the metal from the attacks of water, air, acids or alkalis, or even from heat. Also, aluminium is a good conductor of heat, which helps in the cooking process. It is easily available, malleable, and ductile as well. These factors make it suitable for cooking utensils.

(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction because it is easier to extract the metal from its oxide than compared to carbonates and sulphides. This is also economically feasible and profitable.


7. Four metals A, B, C, and D are, in turn, added to the following solutions one by one. The observations made are tabulated below:

Metal

$FeS{{O}_{4}}$

$CuS{{O}_{4}}$

$ZnS{{O}_{4}}$

$AgN{{O}_{3}}$

A

No reaction

Displacement

---

---

B

Displacement

---

No reaction

---

C

No reaction

No reaction

No reaction

Displacement

D

No reaction

No reaction

No reaction

No reaction

Answer the following questions based on the above information.

(i) Which is the most active metal and why?

(ii) What would be observed if B is added to a solution of copper (II) sulfate and Why?

(iii) Arrange the metals A, B, C, and D in order of increasing reactivity.

(iv) Container of which metal can be used to store both zinc sulfate solution and silver nitrate solution.

(v) Which of the above solutions can be easily stored in a container made up of any of these metals?

Ans:

(i) B is the most reactive metal because it displaces the iron from its solution, which is the most reactive of all the elements.

(ii) It is clear that B is more reactive than iron, and since copper is less reactive than iron, B can displace copper from $CuS{{O}_{4}}$.

(iii) The decreasing order of reactivity is B > A > C > D.

(iv) Metal D can be used to make containers because out of all four elements, it is the least reactive. Also, it shows no displacement reactions with both zinc sulfate solution and silver nitrate solution.

(v) Zinc sulfate can be easily stored in a container made up of any of these metals, because it shows no reaction with these metals.


Important Questions of Class 10 Science Chapter 3: Download Free PDF

To pass the board test in science, you must have a great deal of insight and information. Because it is a challenging subject, acquiring a thorough comprehension of the chapter is critical. Metals and nonmetals is an important scientific chapter that will help you comprehend the different metals and nonmetals, as well as their physical and chemical properties and distinctions. Students will also be familiar with ionic substances and their characteristics. The chapter also discusses ores, alloys, and their characteristics.


Vedantu provides free key questions and answers on metals and nonmetals in Science chapter three. Students may easily view the document on the Vedantu website and obtain the key questions. Class 10 Chapter 3 is a superior resource for pupils studying for the board test.


Metal And Non-Metal Class 10 Important Questions

Metals and non-metals is an important chapter. It helps the students get a better idea about the periodic table, valency, the physical and chemical properties that help differentiate between the metals and non-metals on. Here, we have a brief description of the various topics of the chapter and the important sections. 

There are various types of materials present around us, and these elements are classified as metals and non-metals. To distinguish an element as metal or non-metal, it is crucial to know about their physical and chemical properties. Metals are good conductors of electricity and heat like aluminium and copper. Non-metals, on the other hand, are insulators like sulphur and phosphorus. We have assembled chapter 3 science class 10 important questions for all students.


Definition of Metals

The periodic table consists of elements of which most of them are metals, including transition metals, alkali metals, alkaline earth metals, actinides, and lanthanides. Starting from carbon to radon, a zigzag line separates metals from non-metals. Iodine, phosphorus, and selenium are the elements that fall in between metals and non-metals. The elements right to these, including these, are known as non-metals. The metals left to the line are known as metalloids or semimetals. Metalloids have a combination of the properties of both metals and non-metals. The elements like metals lose electrons and form positive ions which is why it is known as electropositive elements. 


Physical Properties of Metals

  • Except for soft metals like alkali metals like lithium, sodium, potassium, and more, most metals are solid and hard. Mercury, on the other hand, is the only metal in a liquid state and at room temperature. 

  • Most of the metals on the periodic table have high tensile strength and are powerful. Iron and copper are used to make solid and big structures. 

  • Except for mercury, metals are solid and at room temperature. 

  • Metals are known as resonant as they make a ringing sound. These sounds are identified as metallic tones. Metallic wires are used in creating musical devices. 

  • Electric cables are made of either aluminium or copper because metals are good conductors of electricity and heat. 

  • Metals can be beaten to form thin sheets which makes them malleable. This is the reason; ships are built on iron sheets. 

  • Metal wires are often used in electric boxes and for other purposes. These are ductile, strong and can be beaten to thin wires. 

  • Except for sodium and potassium, which have low melting and boiling points, metals usually have high boiling and melting points. 

  • The density of metals is high. 

  • Except for gold and copper, metals are usually grey.


Chemical Properties of Metals

  • All metals when combines with oxygen from metal oxides. For example, copper, when reacts with oxygen forms copper oxides. Aluminium, when reacts with oxygen forms aluminium oxides.

  • Metal oxides are basic. However, metal oxides like zinc oxide, aluminium oxides show both basic and acidic behaviour. Such metal oxides react with both bases and acids to form water and salt. These are known as amphoteric oxides. 

  • Most of the metal oxides are not soluble in water. However, some of the metal oxides dissolve in water and form alkali. 

  • All metals do not react similar way with oxygen. Metals like sodium and potassium when reacts with oxygen can catch fire if kept in the open. Therefore, these metals are dipped in kerosene oil for protection against fire. 

  • Magnesium, zinc, lead, etc. are covered with a thin layer of oxide at ordinary temperature to protect them from further oxidation. 

  • Copper does not burn under the burner because of its covering layer of copper oxide. Even at high temperatures, Gold and silver do not react with oxygen. 

  • Metals are great reducing agents. 

  • Metals have fewer electronegativities. 


What are Non Metals?

There are only a few non-metals present on the right side of the periodic table. Hydrogen, carbon, phosphorus, sulphur, oxygen, nitrogen, selenium, and all halogen and noble gases are non-metals. Non-metals are soft and dull in appearance. If tapered with a hammer, the non-metals break down into a thin powder. The non-metals are poor conductors of electricity and heat. 


Physical Properties of Non-Metals

  • The hard non-metals are brittle and dull in colour. They can be easily broken down into powder with one tap of hammer-like sulphur and copper. However, the hardest non-metal among them is a Diamond. 

  • Non-metals are present in the three states of matter, either solid, gaseous, or liquid. 

  • Except for Graphite, non-metals are poor conductors of electricity and heat. 

  • The metallic lustre is absent in non-metals. 

  • Non-metals do not make any ringing sound and are not sonorous. 

  • Non-metals cannot be beaten to thin sheets and are not malleable.

  • Non-metals cannot be beaten to thin wires and are non-ductile. 


Chemical Properties of Non-Metals

  • Non-metals form non-metallic oxide when reacts with oxygen. 

  • Carbon monoxide is formed when carbon is burned in less supply of air. However, it is a toxic substance and can turn fatal. 

  • Sulphur can catch fire when reacts with oxygen.

  • The non-metallic oxides are acidic and turn blue litmus red in a la liquid state. 

  • Non-metals produce chloride when in contact with chlorine gas. 

  • The outer shell generally had four to eight electrons. 

  • It can easily lose it to gain valance electrons.

  • Non-metals have high electronegative elements.


Class 10 Chapter 3 Important Questions

A set of metal and non-metals important questions will help the students study the chapter thoroughly, and get through various mock tests and competitive exams. The expert team of Vedantu has assembled a set of ten important questions which will help the students to cover the base and prepare for their board's exams. 

  1. Give one example each:

  • A hardest non-metal

  • A soft metal that you can cut with sharp objects

  • A metal at room temperature in the liquid state

  • A non-metal in a liquid state at room temperature

  1. Name the metals:

  • Two metals to make stainless steel

  • Two metals used in jewellery making

  1. Write three reasons for the following with a supportive chemical reaction. 

  • Magnesium is a metal.

  • Sulphur is a non-metal

  1. What is cinnabar? Explain how metal is extracted from it.

  2. With the transfer of electrons, show the formation of KCL.

  3. Write the electron structure of sulphur and calcium. With the transfer of electrons, show the formation of CaS. With an atomic number of calcium as 20 and sulphur as 16, lead the atoms present on CaS.

  4. With the help of magnesium ribbon and sulphur powder, show that non-metals are acidic in nature and metal oxides are basic. 

  5. Give reasons:

  • Electric wires are made of wires.

  • School bells are made of metals.

  1. Why and which metals are dipped in kerosene.

  2. Name a metal that melts when kept on the palm. 


Benefits of Ch 3 Science Class 10 Important Questions

Class 10 Science Metals and Non-metals important questions will help the students prepare for their final exams and are beneficial for the following reasons.

  • The metals and non-metals important questions will help the students to practice the chapter instantly while revising it. It is the best last-minute revision set before the exams. 

  • The important question set consists of all the necessary topics that the students must know about the chapter. It is the best example of a group of questions that will give the students an idea about the upcoming paper. 

  • Extra questions for class 10 Science chapter 3 are available for free at the Vedantu website, helping the students gain confidence before sitting for their finals. 


Conclusion

Class 10 Science chapter 3 crucial questions are intended for students who are preparing to take competitive examinations or who are going to take their board exam. Science is a difficult subject that requires a lot of hard study and review before examinations. The experienced team's preparation of these class 10 science ch 3 crucial questions will assist students in covering all areas and becoming confident before examinations.


Important Related Links for CBSE Class 10 Science

FAQs on Important Questions for CBSE Class 10 Science Chapter 3 - Metals and Non-metals 2024-25

1. What are Metals? What are its Properties?

Metals are opaque, lustrous elements that are good conductors of heat and electricity. Most metals are malleable and ductile and are, in general, denser than the other elemental substances.


The Physical and Chemical Properties of Metals are as follows:  

Some of the physical properties of metals are listed below.

  • Shiny (lustrous) in nature

  • Metal is a good conductor of electricity and heat

  • Density and melting point is high

  • Mouldable (Malleable)

  • Ductile

  • At room temperature, it is in solid form except for mercury

  • Opaque

Some of the chemical properties of metals are listed below.

  • Easily corrodible

  • Can lose electrons

  • Form basic oxides

  • Have low electronegativities

  • Good reducing agents

2. What are Non-metals? What are its properties?

Non-metal is a chemical element that does not have metal’s properties. They occur in liquid or gaseous states. There are very few non metals in nature and all of them are present in the periodic table. 


The physical and chemical properties of Non-Metals are as follows: 

Some of the physical properties of non-metals are listed below.

  • Poor conductors of electricity and heat

  • Non-Ductile metals

  • Brittle solids

  • Maybe solids, liquids or gases at room temperature

  • These are not sonorous

  • Transparent

Some of the chemical properties of non-metals are listed below.

  • The number of electrons in the outer shell is generally 4-8

  • Easily gain or lose valence electrons

  • Form acidic oxides whenever they come in contact with oxygen

  • High electronegative elements

  • Great oxidizing agents

3. What is an Alkaline metal? What is the electronic configuration of alkali metals?

Alkali metals are any of the elements found in Group IA of the periodic table (the first column). Alkali metals are very reactive chemical species that readily lose their one valence electron to form ionic compounds with nonmetals. In general ‘alkali’ refers to the basic or alkaline nature of their metal hydroxides.


The electronic Configuration of Alkali Metals are as follows: 

  • Alkali metals have only one electron in their valence shell.

  • The electronic configuration is given by ns1. For example, the electronic configuration of lithium is given by 1ns1 2ns1.

  • They tend to lose the outer shell electron to form cations with charge +1 (monovalent ions).

  • This makes them the most electropositive elements and due to the same reason, they are not found in the pure state.

  • They readily give away their valence electrons to form strongly bonded compounds with non-metals.

4. Why should students refer to the NCERT Solutions of class 10 chapter 3 - Metals and Non-metals?

Students should  refer to the NCERT Solutions of class 10 chapter 3 - Metals and Non-metals for the follows reasons: 

  • The answers and solutions provided here are absolutely correct, easy to understand and easy to remember. 

  • This NCERT solution ensures that it provides all the answers to all the questions in all the exercises. 

  • These solutions also ensure that they even provide answers to all the exercises even in between the lesson

  • The answers given in the NCERT Solutions are curated in a way as to make students understand the correct method of answering a question in the exam. The answers in these solutions are written by subject matter experts making the solutions all the more reliable. 

5. Name some chemical properties of metals according to Chapter 3 of Class 10 Science.

As discussed in Chapter 3 of Class 10 Science, some chemical properties observed in metals include:

  • Usually, metals have a high density.

  • All metals are ductile and malleable.

  • All metals are generally in a solid-state at room temperature. However, mercury is an exception as it is in a liquid state at room temperature.

  • While lead is an exception, all other metals are good conductors of electricity and heat.

6. What is meant by corrosion of metals?

Corrosion refers to a natural phenomenon that causes damage to metals. This process leads to the accumulation of rust on the metal surfaces, which is usually a result of the reactions that occur due to oxygen and moisture present in the air. Corrosion leads to the formation of many new products like oxide, sulphide, or hydroxide. The equations of corrosion differ depending upon the different metals and the chemical reactions being involved.

7. What are the important questions for Chapter 3 of Class 10 Science?

Chapter 3 in Class 10 Science includes many important questions. Some examples of these important questions include:

  • “Name two metals that are found in nature in their free state.”

  • “What types of oxides are formed when nonmetals combine with oxygen?”

  • “Which gas is produced when a metal reacts with dilute hydrochloric acid? Write the chemical reaction for iron reacting with dilute H₂SO₄.”

8. What are the most important topics covered in Chapter 3 of Class 10 Science?

While it is essential to prepare all topics that are part of Class 10 Science Chapter 3, students must make sure that they put in extra focus and practice for the following topics as they hold higher importance from the exam’s point of view:

  • The Reactivity Series

  • Extraction of Metals

  • Refining of Metals

Students can also find these topics covered in the Important Questions for CBSE Class 10 Science Chapter 3 - Metals and Non-metals.


9. How are important questions for Class 10 Science Chapter 3 beneficial?

Referring to Important Questions for CBSE Class 10 Science Chapter 3 - Metals and Nonmetals are meant to help students by providing ready-made study material that they use for practice and revisions as well. These important questions can also be beneficial by saving time and helping in last-minute quick revisions of the chapter. These questions cover all the important topics that students must prepare well before their exams and these are available free of cost on Vedantu’s e-platform.