NCERT Solutions for Class 10 Science Chapter 3 - Metals and Non Metals

Intext Questions:

1. Give an example of a metal which

i. is a liquid at room temperature. 

Ans: Mercury

ii. can be easily cut with a knife. 

Ans: Potassium

iii. is the best conductor of heat. 

Ans: Copper and Silver

iv. is a poor conductor of heat.

Ans: Mercury.

2. Explain the meanings of malleable and ductile.

Ans: Malleable: Property of a metal due to which it can be beaten into thin sheets is known as malleability and the metal is known to be malleable. 

Ductile: Property of a metal due to which it can be beaten into thin pipes/wire is known as ductility and the metal is known to be ductile.

Intext Questions:

1. Why sodium is kept immersed in kerosene oil?

Ans: Sodium is a very reactive metal. It reacts with the air and catches fire as soon as it comes in contact with it. Hence, to avoid such accidents sodium is kept immersed in kerosene oil.

2. Write equations for the reactions of

i. iron with steam 

Ans: $3 \mathrm{Fe}(\mathrm{s})+4 \mathrm{H} 2 \mathrm{O}(\mathrm{g}) \rightarrow \mathrm{Fe3O4}(\mathrm{s})+4 \mathrm{H} 2(\mathrm{~g})$

ii. calcium and potassium with water

Ans: $\mathrm{Ca}(\mathrm{s})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}(\mathrm{aq})+\mathrm{H}_{2}(\mathrm{~g})$

$2 \mathrm{~K}(\mathrm{~s})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow 2 \mathrm{KOH}(\mathrm{aq})+\mathrm{H}_{2}(\mathrm{~g})+$ heat

3. 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:

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

According to the activity series the most reactive metal displaces the least reactive metal. according to the given table we can say that: 

$\mathrm{A}$ is less reactive than iron but more reactive with copper.

$\mathrm{A}+\mathrm{FeSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{A}+\mathrm{CuSO}_{4} \rightarrow \text { Single Displacement }$

B is more reactive than iron but less reactive than zinc.

$\mathrm{B}+\mathrm{FeSO}_{4} \rightarrow \text { Single Displacement }$

$\mathrm{B}+\mathrm{ZnSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{C}$ is less reactive than iron, copper and zinc but more reactive with silver

$\mathrm{C}+\mathrm{FeSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{C}+\mathrm{CuSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{C}+\mathrm{ZnSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{C}+\mathrm{AgNO}_{3} \rightarrow \text { Single Displacement }$

D is less reactive than iron, copper,zinc, and silver

$\mathrm{D}+\mathrm{FeSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{D}+\mathrm{CuSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{D}+\mathrm{ZnSO}_{4} \rightarrow \text { No reaction }$

$\mathrm{D}+\mathrm{AgNO}_{3} \rightarrow \text { No Reaction }$

i. Which is the most reactive metal? 

Ans: B is the most reactive metal. 

${\text{B}} + {\text{FeS}}{{\text{O}}_4} \to {\text{Single Displacement}}$

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

Ans: When B is added to a solution of copper (II) sulphate then it shows the single displacement because B is more reactive than iron. 

${\text{B}} + {\text{CuS}}{{\text{O}}_4} \to {\text{Single Displacement}}$

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

Ans: ${\text{B}} > {\text{A}} > {\text{C}} > {\text{D}}$

4. Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute $\mathrm{H}_{2} \mathbf{SO}_{4}$.

Ans: Iron is more reactive than hydrogen according to the reactivity series. So, when iron comes in contact with dilute $\mathrm{H}_{2} \mathrm{SO}_{4}$ it replaces hydrogen to form iron sulphate and in the reaction it releases hydrogen gas.

${\text{F}}{{\text{e}}_{(s)}} + {{\text{H}}_2}{\text{S}}{{\text{O}}_{4(aq)}} \to {\text{FeS}}{{\text{O}}_{4(aq)}} + {H_{2(g)}}$

5. What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes place.

Ans: According to the reactivity series we know zinc is more reactive than iron. So, when zinc comes in contact with iron sulphate solution it replaces iron and forms zinc sulphate. And the colour of solutions turns brown from green.

${\text{Z}}{{\text{n}}_{(s)}} + {\text{FeS}}{{\text{O}}_{4(aq)}} \to {\text{ZnS}}{{\text{O}}_{4(aq)}} + F{e_{(s)}}$

Intext Exercise:

1. Answer the following:

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

Ans: Sodium, oxygen and magnesium atomic numbers are 11, 8 and 12. The electron dot structures are below:

Sodium (2,8,1) = $\overset{\text{X}}{\mathop{\text{Na}}}\,$

Oxygen (2,6) =

Magnesium (2,8,2) = $\overset{\text{XX}}{\mathop{\text{Mg}}}\,$

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

Ans: Both of the compounds will form an ionic bond.

iii. What are the ions present in these compounds?

Ans: In the $\mathrm{Na}_{2} \mathrm{O} \text {, the ions } 2 \mathrm{Na}^{+} \text {and } \mathrm{O}^{2} \text { - and in } \mathrm{MgO} \text { are } \mathrm{Mg}^{2+} \text { and } \mathrm{O}^{2} \text { - }$.

2. Why do ionic compounds have high melting points?

Ans: Ionic compounds have high electrostatic force between the molecules due to which they are very closely packed and rigid. This tight packing results in ionic compounds having high melting points. 

Refer to page 53.

1. Define the following terms.

i. Minerals: 

Ans: The minerals which are present as a mixture of metallic compounds and extractable impurities are known as ores and the compound of a metal found in nature is called mineral.

ii. Ore:

Ans: The minerals from which the metals can be conveniently and economically extracted are known as ores.

iii. Gangue:

Ans: The ore contains some impurities like sand, clay and rocky material. These impurities are called gangue or matrix. Gangue is removed before the metallurgical process starts.

2. Name two metals which are found in nature in the free state.

Ans: Silver and Gold are found in free state as their reactivity potential is very low.

For example: Silver(Ag), Gold (Au), and Platinum(Pt).

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

Ans: More reactive metals are reduced by the electrolysis process. moderate reactive metals can be reduced by either carbon or carbon monoxide. Metal oxides are reduced by using suitable reducing agents such as carbon or by highly reactive metals to displace the metals from their oxides. For example, zinc oxide is reduced to metallic zinc by heating with carbon.

$\mathrm{ZnO}_{(s)}+C_{(s)} \stackrel{\Delta}{\longrightarrow} \mathrm{Zn}_{(s)}+\mathrm{CO}_{(g)}$ or

$\mathrm{ZnO}+\mathrm{CO} \rightarrow \mathrm{Zn}+\mathrm{CO}_{2}$

Thermite process: Chromium oxides are reduced to chromium by treating it with aluminium powder. In this case, aluminium displaces manganese from its oxide.

${\text{C}}{{\text{r}}_2}{{\text{O}}_3} + 2{\text{Al}} \to {\text{A}}{{\text{l}}_2}{{\text{O}}_3} + 2{\text{Cr}} + {\text{heat}}$

Refer to page 55.

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

In which cases will you find displacement reactions taking place?

Ans:

2. Which metals do not corrode easily?

Ans: Metals with less reactivity such as silver, platinum and gold.

3. What are alloys?

Ans: An alloy is a homogenous mixture of two metals or metal and non-metals. They are formed by melting the metals and mixing them and then solidifying them into alloy.

Example: Bronze is an alloy of copper and tin.

Exercise Questions

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

(a) $\mathbf{NaCl}$ solution and copper metal            

(b) $\mathbf{MgC}{{\mathbf{l}}_{\mathbf{2}}}$ solution and aluminium metal 

(c) $\mathbf{FeS}{{\mathbf{O}}_{\mathbf{4}}}$ solution and silver metal               

(d) $\mathbf{AgN}{{\mathbf{O}}_{\mathbf{3}}}$ solution and copper metal.

Ans: (d) $\mathbf{AgN}{{\mathbf{O}}_{\mathbf{3}}}$ solution and copper

2. Which of the following methods is suitable for preventing an iron frying pan from rusting? 

(a) Applying grease

(b) Applying paint 

(c) Applying a coating of zinc

(d) all of the above.

Ans: (c) Applying a coating of zinc

3. 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 

(a) calcium

(b) carbon 

(c) silicon

(d) iron

Ans: (a) calcium

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

(a) zinc is costlier than tin.

(b) zinc has a higher melting point than tin. 

(c) zinc is more reactive than tin.

(d) zinc is less reactive than tin.

Ans: (c) zinc is more reactive than tin.

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

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

Ans: Metals are naturally malleable. We can beat the given sample with the help of a hammer. If it turns into thin sheets, it is metal; otherwise, it is nonmetal.

Metals carry electricity. when we use a battery, a lamp, wires, and a switch to create a circuit. If the bulb glows, it indicates that the sample is metallic due to liberated electrons. If the bulb does not light up, this indicates that the sample is non-metallic.

(b) Assess the usefulness of these tests in distinguishing between metals and nonmetals.

Ans: The physical properties of metals and non-metals are represented by these tests. We can easily distinguish between them based on their physical characteristics.

6. What are amphoteric oxides? Give two examples of amphoteric oxides.

Ans: Oxides which can react with both acid and base is known as amphoteric oxide.

Example: Zinc oxide $(ZnO)$ and Aluminum oxide$\left(\mathrm{Al}_{2} \mathrm{O}_{3}\right)$

7. Name two metals which will displace hydrogen from dilute acids, and two metals which will not.

Ans: More reactive metals will displace hydrogen from its dilute acids. for example : Iron and Zinc.

$\mathrm{Fe}+2 \mathrm{HCl} \rightarrow\mathrm{FeCl}_{2}+\mathrm{H}_{2}$

$\mathrm{Zn}+2 \mathrm{HCl} \rightarrow\mathrm{ZnCl}_{2}+\mathrm{H}_{2}$

Least reactive metals will not displace hydrogen from its dilute acids. for example : copper and silver

$\mathrm{Cu}+\mathrm{HCl} \rightarrow$ No Reaction

$\mathrm{Ag}+\mathrm{HCl} \rightarrow$ No Reaction

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

Ans: In the electrolytic refining of a metal M: 

i. Cathode → Pure metal M 

ii. Anode → Impure metal M 

ii. Electrolyte → Salt Solution of the metal M

9. Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.

(a) What will be the action of gas on 

i. dry litmus paper? 

Ans: no reaction with dry litmus paper.

ii. moist litmus paper? 

Ans: Moist blue litmus will turn red due to the formation of sulphur dioxide. Sulphur dioxide is acidic oxide when it will react with water converts into sulphurous acid.

(b) Write a balanced chemical equation for the reaction taking place.

Ans: $\mathrm{S}_{(s)}+\mathrm{O}_{2(g)} \longrightarrow \mathrm{SO}_{2(g)}$

$\mathrm{SO}_{2(g)}+\mathrm{H}_{2} \mathrm{O}_{(l)} \longrightarrow \underset{\text { Sulphur dioxide }}{\longrightarrow} \mathrm{H}_{2} \mathrm{SO}_{3(a q)}$

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

Ans: The process of degrading metals in presence of air and water is known as rusting. Two ways in which rusting can be prevented are as follows:

1. Painting: It prevents iron from coming in direct contact with air and water.

2. Galvanization: In this process iron is coated with a layer of zinc.
   
   

11. What type of oxides is formed when nonmetals combine with oxygen?

Ans: Non-metals combine with oxygen and form acidic oxides which when combined with water turns into acidic solution.

12. Give reasons

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

Ans: These metals are very less reactive and are lustrous which makes them suitable for making jewelry.

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

Ans: They are highly reactive metals and catch fire as soon as it comes in contact with the air. Hence, to avoid any accidents these metals are kept under oil.

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

Ans: Aluminium is highly reactive and they react with oxygen present in atmosphere to form a stable compound $\mathrm{Al}_{2} \mathrm{O}_{3}$. Along with this, they are very good conductor of heat. Therefore, aluminium is used in making utensils for cooking.

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

Ans: Extracting metals from their oxides are easier as compared to their carbonate and sulphides. Therefore, ores are usually converted into oxides by the process of roasting and calcination.

13. 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 forms basic copper carbonate ${\text{(CuC}}{{\text{O}}_{\text{3}}}{\text{.Cu(OH}}{{\text{)}}_{\text{2}}}{\text{)}}$ when it combines with damp carbon dioxide in the air. It turns green, and the copper vase loses its gleaming brown finish. The presence of citric acid in the lemon or tamarind neutralizes the basic copper carbonate and dissolves the layer.

14. Differentiate between metals and non-metals.

Ans: Differences between metals and non-metals are as follows:

15. A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold 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 is using Aqua Regia which is 3 parts of $\mathrm{HCL}$ and 1 part of $\mathrm{HNO}_{3}$ solution. Gold is the least reactive metal but when we put it in aqua regia the upper most layer gets dissolved in the solution and the inner layer comes out due to which it weighs less than before but is glitterier.

16. Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

Ans: In the reactivity reaction copper comes below hydrogen and hence, it will not react with the water present/stored. On the other hand, steel which is an alloy of iron will react with the steam and can get corroded easily.

Ch 3 Science Class 10 Quick Overview of Metals and Non Metals 

Important Points Covered in Metals and Non-Metals Class 10 PDF 

• Metals and non-metals are two types of elements. Metals are shiny, malleable, ductile, and excellent heat and electricity conductors. Except for mercury, which is a liquid at normal temperature, all are solids.

• Metals have the ability to form positively charged ions by donating electrons to nonmetals.

• When metals react with oxygen, they produce basic oxides 

• Aluminum oxide and zinc oxide exhibit characteristics of both basic and acidic oxides. These oxides are called Amphoteric oxides.

• Different metals exhibit diverse levels of reactivity when they come into contact with water and dilute acids.

• An activity series is a list of common metals grouped in decreasing order of reactivity.

• Metals placed above hydrogen in the Activity series have the capability to replace hydrogen in dilute acids.

• When non-metals receive electrons from metals, they produce negatively charged ions, which are then converted into acidic or neutral oxides.

• Non-metals do not displace hydrogen from dilute acids; instead, they form hydrides upon reacting with hydrogen.

Benefits of Vedantu’s NCERT Science Chapter 3 Class 10 Question Answer

• Vedantu's NCERT Class 10 Science Ch 3 Question Answer thoroughly covers the chapter, ensuring a deep understanding of concepts related to metals and non-metals.

• Class 10th Science Chapter 3 Question Answer discusses the formation of oxides by metals and non-metals and their reactions with acids and bases.

• Each solution is presented step-by-step, helping to improve understanding and problem-solving skills development.

• Vedantu's NCERT Solutions for Metal and Non-Metals Class 10 focuses on enhancing conceptual clarity and helping students build a strong foundation in metallurgy and the properties of metals and non-metals.

• Class 10th Science Chapter 3 Question Answer delves into the process of corrosion in metals and discovers methods to prevent it, such as alloying and coating.

• Utilising Vedantu's Metals and Non-Metals Class 10 Solutions helps improve students' academic performance and confidence in tackling questions related to metals and non-metals.

Related Study Materials for Metals and Non-Metals Class 10 

Students can also download additional study materials provided by Vedantu for Ch 3 Science Class 10.

Conclusion

Vedantu's NCERT Class 10 Science Ch 3 Question Answer offers an essential resource for students aiming to grasp the concepts effectively. The solutions simplify complex topics, providing clarity and understanding. Key focus areas include understanding the properties of metals and non-metals, their reactivity, and their uses in daily life. Additionally, reviewing previous year's question papers reveals that this chapter typically includes around 5-7 questions, making it vital for students to thoroughly grasp the material covered in the chapter to excel in their exams. With Vedantu's assistance, mastering the concepts of metals and non-metals becomes both accessible and achievable.

Links for Chapter-wise NCERT Solutions Class 10 Science

Important Study Materials Links for for Class 10 Science