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

NCERT solutions for class 10 science chapter 3 Metals and Non-metals: Through this chapter, you will get to know about elements those can be classified as metals and non-metals. The NCERT solutions for class 10 science chapter 3 Metals and Non-metals are created by the experts which will help you to clear your concepts and doubts related to the chapter. Learning the fundamentals in science subject is very important, so, with the help of solutions for CBSE class 10 science, this becomes easy. You can easily score well by practicing the questions with the help of NCERT solutions for class 10 science chapter 3 Metals and Non-Metals. The NCERT solutions provide answers to all the exercises questions and as well as to the questions mentioned in between the chapter.

The solutions provided in this article are based on the CBSE syllabus for class 10 science. Along with board exams, these NCERT solutions for class 10 will help you to crack competitive exams such as JEE, NEET, KVPY, NTSE, etc. and it will also help you to complete your homework and assignments. Before getting into the details of CBSE NCERT solutions for class 10 science chapter 3 Metals and Non-Metals, let's check what you will get to know in the chapter 3 Metals and Non-Metals:

Things you will get to know through NCERT solutions for class 10 science chapter 3 Metals and Non-Metals:

• Metals are shiny, easily pliable, ductile and are good conductors of heat and electricity.
• Metals are solids at room temperature, except mercury which is a liquid. By losing electrons to non-metals, they can form positive ions.
• Metals combine with oxygen to form basic oxides. Aluminum oxide and zinc oxide show the properties of both basic as well as acidic oxides. These oxides are known as amphoteric oxides. Different metals have different reactivities with water and dilute acids.
• You will study that a list of common metals arranged in order of their decreasing reactivity is known as an activity series.
• Non-metals have properties opposite to that of metals. Non-metals are neither malleable nor ductile.
• Except for graphite which conducts electricity, other non- metals are bad conductors of heat and electricity.
• When reacting with metals, non-metals form negatively charged ions by gaining electrons. They form oxides that are either acidic or neutral.
• They do not displace hydrogen from dilute acids. They react with hydrogen to form hydrides.

## NCERT solutions for class 10 science chapter 3 Metals and Non-Metals - solutions

Topic 3.1 - Physical Properties

Generally, metals are solid at room temperature as they have a strong metallic bond that binds them close.

But mercury is a metal which exists as a liquid metal at room temperature.

Metal is generally hard in nature due to its metallic bond between each other. But sodium is a metal which is so soft that it can even be cut with a knife.

Most of the metals are a good conductor of heat and electricity but silver is considered the best conductor of heat and electricity among them (gold and copper are also very good conductors).

Generally, metals are considered a good conductor of heat and electricity. But mercury and lead show slight exception as they are a poor conductors of heat.

Malleable substances are the substance which can be beaten in order to convert them into sheets. Generally, all metals are considered to be malleable in nature.

For example silver, iron, etc. Gold has the highest malleable property as one single gram of gold can be beaten into a sheet of 1 square meter.

Ductile substances are substances which can be drawn into wires. All the metals like gold, copper are dectile in nature. Moreover, the wires for transfer of electricity are made of copper.

## NCERT free solutions for class 10 science chapter 3 Metals and Non- Metals

Topic 3.2: Chemical properties of metals

Sodium is a very reactive metal. It reacts rapidly with the oxygen and thus cannot be kept in air as it will explode. So it is better to store in a liquid.

Further the density of sodium is less than that of water so it will float on the surface. So water is not a good solvent for the purpose. So sodium is kept in kerosene oil.

## Q.2.  (i)    Write equations for the reactions of  iron with steam

Iron reacts with steam and forms iron oxide. The reaction is shown below :

Calcium and potassium react with water to give their respective hydroxides. The reactions are shown below :

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

(i) Which is the most reactive metal?

 Metal Iron (II) sulphate Copper (II) sulphate Zinc sulphate Silver nitrate 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

From the table, it can be seen that no metal is able to displace zinc from its solution thus zinc is most rection among given metals. Further, only metal B is able to displace iron from iron sulphate solution. And element A can displace copper. Similarly, element C can displace silver from its solution.

So the reactivity order obtained is :            D      <      C    <      A     <     B

Hence B is most reactive.

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

 Metal Iron (II) sulphate Copper (II) sulphate Zinc sulphate Silver nitrate 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

As we have seen part (a)  that element A can displace copper from its solution. Also, B is more reactive than element A.

So element B will also displace copper from copper sulphate solution.

Question:

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

 Metal Iron (II) sulphate Copper (II) sulphate Zinc sulphate Silver nitrate 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

As stated in part (a):-

No metal is able to displace zinc from its solution thus zinc is most rection among given metals.

Further, only metal B is able to displace iron from iron sulphate solution. And element A can displace copper. Similarly, element C can displace silver from its solution.

So the reactivity order obtained is :            D      <      C    <      A     <     B

In the case when dilute hydrochloric acid is added to a reactive metal we obtain hydrogen gas. The reaction when suphuric acid reacts a reactive metal is shown below :

In this reaction, we obtain iron suphate solution with release of hydrogen gas.

By reactivity, we know that zinc is more reactive than iron. Thus zinc will displace iron from the iron sulphate solution and form zinc sulphate. The reaction is shown below:-

## NCERT solutions for class 10 science chapter 3 Metals and Non-Metals

Topic- 3.3: How do metals and non-metals react?

The electron dot structure for sodium, oxygen, and magnesium is shown below:-

## Q.1. (ii)   Show the formation of and by the transfer of electrons.

The formation of Na2O and MgO is shown below:-

In $N\! a_{2}O$ the ions present are Na+  and O2-,  whereas in $M\! gO$  the ions are Mg2+ and O2-.

The ionic compounds have a very strong electrostatic force of attraction. To overcome these force very high energy is needed. Thus it is generally seen that the melting point of ionic compounds is quite high.

## CBSE NCERT solutions for class 10 science chapter 2 Metals and Non- Metals

Topic-3.4: Occurrence of metals

Q.1. (i)    Define the following terms - Mineral.

In nature, the elements are present in a combined state known as minerals. Minerals may be defined as the solid chemical compound that occurs naturally in pure form. The chemical composition of minerals is said to the same throughout.

Q.1. (ii)    Define the following terms- Ore.

Ores are defined as the minerals which can be extracted to make profits. Only economically extractable elements (generally metals) are considered to be ores.

## Q.1. (iii)    Define the following term- Gangue.

Gangue is the impurities present in the ores such as sand, silt soil. To make the element efficient and more useful, we need to remove the gangue from the ores.

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

The metals which are very low reactive elements may be found in free states. Two such metals are gold and silver. These metals are so unreactive that they don't form any oxides, peroxides or sulphides.

We can obtain metal from its oxide by using the reduction process. The metal oxides are reduced using reducing agents such as highly reactive metals so that they can displace the metal from its oxide.

For e.g.  From zinc oxide, we can get zinc by using reducing agent carbon.

$ZnO\ +\ C\ \rightarrow \ Zn\ +\ CO$

## NCERT solutions for class 10 science chapter 3 Metals and Non-Metals

Topic 3.5 Corrosion

 Metal Zinc Magnesium Copper Zinc oxide Magnesium oxide Copper oxide

The reactivity order of the given elements are: Mg   >   Zn     >   Cu

Thus the following result is observed :

 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

## Q.2.    Which metals do not corrode easily?

The low reactive metals such as gold don't corrode easily whereas highly reactive elements are very easily corroded.This is why these metals (highly reactive) are given gold plating in order to protect them from corrosion.

Q.3.    What are alloys?

Alloys are defined as the homogeneous mixture of two or more than two elements. Alloys are prepared to give specific features of all the constituent elements. It is prepared by melting one metal and then diffusing other into.

For example:  steel is an alloy of iron and carbon.

## NCERT solutions for class 10 science chapter 3 Metals and Non-Metals Exercise Solutions:

a) NaCl solution and copper metal

b) $MgCl_{2}$ solution and aluminum metal

c) $FeSO_{4}$ solution and silver metal

$(d) AgNO_{3}$  solution and copper metal.

In all other options, the solution metal is more reactive than the given metal.

For e.g.  in  $(b) MgCl_{2}$  solution and aluminum metal, Mg metal is more reactive than aluminum thus reactive will not take place.

(a) Applying grease
(b) Applying paint
(c) Applying a coating of zinc
(d) All of the above.

(c) Applying a coating of zinc

It will be most suitable method to prevent it. Paint and grease can also be applied but these are not suitable methods as the pan will be heated and washed again and again.

(a) calcium
(b) carbon
(c) silicon
(d) iron.

The element is Calcium. As calcium oxide is soluble in water and has a high melting point.

(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.

This is because zinc is more reactive than tin. So zinc may react with food items and make food unhealthy to consume.

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

To distinguish between metals and non-metals we can use two properties of metals:-

(i) Most of the metals are malleable i.e., they can be converted into sheets. So with the help of a hammer, we can test and distinguish.

(ii) Metals are a good conductor of electricity whereas non-metals are poor conductors.

Assess the usefulness of these tests in distinguishing between metals and non-metals.

These are useful as there is no chemical reaction involved in identifying the metals and non-metals. These are just the physical test which can be carried out at any level. As in the first test, the hammer is easily available at home. And in the second test, we have use wires which are easily available in the market.

Amphoteric oxides are those oxides of metals that behave in both acidic and basic manner. These oxides react with acids and bases to produce salt and water as the major products. E.g.  Aluminium oxide (Al2O3),  Zinc oxide (ZnO).

Clearly, the metals which are more reactive than hydrogen will displace it from the dilute acids.

For e.g. potassium and sodium. But metals like silver and gold are less reactive than hydrogen so they will not be able to displace hydrogen.

The configuration for electrolytic refining will be:-

Electrolyte:- Salt solution of metal M

Anode:- Impure metal M

Cathode:- Pure metal M (Thin strips)

In the given procedure sulphur dioxide is formed.

(i) Thus gas (sulphur dioxide) has no effect on dry litmus paper.

(ii) SO2 converts moist blue litmus paper to red due to the formation of sulphurous acid. (as sulphur dioxide reacts with moisture to produce acid).

In the reaction, sulphur dioxide is formed. The chemical reaction is shown below:-

$S\ +\ O_2\ \rightarrow \ =\ SO_2 (g)$

The two ways to prevent rusting of iron is:-

(a) By making alloys of the elements.

(b) By using the electroplating method such as galvanization.

When non-metals combine with the oxygen they form acidic oxides.

For e.g. SO2 is an acidic oxide formed when sulphur combines with oxygen.

Q.12.(a)  Give reasons:

Platinum, gold, and silver are used to make jewellery.

There are three main reasons for why platinum, gold, and silver are used to make jewellery :-

(i) They are lustrous in nature.

(ii) They are very low reactive elements, thus they don't corrode easily.

(iii) They are found in low quantity so that makes them costly and not available for all. Hence these are used as a sign to show status in society.

Q.12. (b)    Give reasons:

Sodium, potassium, and lithium are stored under oil.

The elements like sodium, potassium, and lithium are very reactive metals. They react with oxygen vigorously and thus are dangerous to keep them in contact with air and moisture. Hence they are generally kept under oil.

Q.12. (c)    Give reasons:

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

This is true that aluminum is a highly reactive element but it has a property of non-corrosion. That's why it is used to make cooking utensils. The property comes from the fact that aluminum reacts with oxygen and forms a thin layer of aluminum oxide which acts as a protective coating layer to resist further corrosion.

Q.12. (d)   Give reasons:

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

This is because the extraction of metal is easier from their oxides rather than their carbonates or sulphides. As in case of oxides we have to simply use a metal more reactive than the impure metal which needs to be extracted.

The lemon and tamarind contains citric acid which neutralizes the basic carbon carbonate and thus dissolves the greenish layer. This is why lemon juice and tamarind is used to clean tarnished copper vessels.

The major differences between metals and non-metals are given below:-

 Metals Non-metals 1. They have ionic bonds. They have covalent bonds 2. They are electropositive. They are electronegative. 3. They form basic oxides. They form acidic oxides. 4. They react with dilute acids to form salt and evolve hydrogen gas. Since they cannot replace hydrogen      thus they cannot react with dilute acids.

The solution man used must be aqua regia. It is a solution of a 3:1 mixture of conc. HCl and conc. HNO3. It has the property that gold dissolves in this solution.

After dipping the gold in the solution, the outer layer of gold dissolves and the new surface is exposed which appears to be shiny. This is why the weigth of ornament is decreased.

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

This is because steel contains iron which reacts with steam and forms iron oxide. Whereas copper doesn't react with cold water, hot water and steam.

That's why hot water tanks are made up of copper, not steel.

$3Fe\ +\ 4H_2O\ \rightarrow \ Fe_3O_4\ +\ 4H_2O$

## NCERT Solutions for Class 10 Science - Chapter wise

 Chapter No. Chapter Name Chapter 1 CBSE NCERT solutions for class 10 science chapter 1 Chemical Reactions and Equations Chapter 2 NCERT free solutions for class 10 science chapter 2 Acids, Bases, and Salts Chapter 3 NCERT solutions for class 10 science chapter 3 Metals and Non-Metals Chapter 4 Solutions for NCERT class 10 science chapter 4 Carbon and Its Compounds Chapter 5 CBSE NCERT solutions for class 10 science chapter 5 Periodic Classification of Elements Chapter 6 NCERT textbook solutions for class 10 chapter 6 Life Processes Chapter 7 NCERT free solutions for science class 10 chapter 7 Control and Coordination Chapter 8 Solutions for NCERT class 10 science class 8 How do Organisms Reproduce? Chapter 9 CBSE NCERT solutions for class 10 science chapter 9 Heredity and Evolution Chapter 10 NCERT textbook solutions for class 10 science chapter 10 Light Reflection and Refraction Chapter 11 NCERT solutions for class 10 science chapter 11 The Human Eye and The Colorful World Chapter 12 CBSE NCERT solutions for class 10 science chapter 12 Electricity Chapter 13 Solutions for NCERT class 10 science chapter 13 Magnetic Effects of Electric Current Chapter 14 NCERT textbook solutions for class 10 science chapter 14 Sources of Energy Chapter 15 NCERT free solutions for class 10 science chapter 15 Our Environment Chapter 16 CBSE NCERT solutions for class 10 science chapter 16 Sustainable Management of Natural Resources

## Benefits NCERT solutions for class 10 science chapter 3 Metals and Non-Metals

• NCERT solutions provided here for chapter 3 metals and non-metals can help you to score well in the CBSE board exam for class 10 science.
• You can also find exercise questions and intext questions in the same place.
• Step-wise step solutions are provided by the experts if you have any doubt you can ask them directly.