# NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Written by Team Trustudies
Updated at 2021-05-07

Metals and Non-metals is 3rd chapter of class 10 science. Ncert solutions for class 10 science chapter 3 Metals and non-metals are made by the expert team at Trustudies for the students of class 10 completely free. Each and every question and answer covered in Metals and Non-metals is 3rd chapter of class 10 science is of the best quality and reflects the topics covered in Ncert book of chapter(ch) 3 class 10 science. These solutions are made for a better understanding of the students so that they can clear the doubts by going through the Ncert solutions for class 10 science chapter 3 Metals and non-metals.

## NCERT solutions for class 10 Science Chapter 3 Metals And Non Metals Exercise

Q1 )

Which of the following pairs will give displacement reactions?

• (a) NaCl solution and copper metal
• (b) $MgC{l}_{2}$ solution and aluminium metal
• (c) $FeS{O}_{4}$ solution and silver metal
• (d)$AgN{O}_{3}$ solution and copper metal.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

To solve this question, we should first remember the definition of displacement reaction which states that those reactions where a more reactive element displaces/removes a less reactive element is called displacement reaction. Now let's look at each option one by one.

(a) NaCl solution and copper metal - In order for this reaction to complete copper(Cu) must replace Na(sodium) but this is not possible as copper is less reactive than sodium(see reactivity series)

(b)$MgC{l}_{2}$ solution and aluminium metal - Here, aluminium(Al) must replace magnesium(Mg) but it is not possible as aluminium(Al) is less reactive than magnesium(Mg)

(c)$FeS{O}_{4}$ solution and silver metal -Here, Ag(Silver) must replace Fe(Iron) but it is not possible

(d) $AgN{O}_{3}$ solution and copper metal - Yes, this reaction is possible as copper(Cu) is more reactive than silver(Ag) so, cu(copper) metal will easily displace Ag and reaction will be

$AgN{O}_{3}+Cu?Cu\left(N{O}_{3}{\right)}_{2}+Ag$

Q2 )

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 the above

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

The most suitable way of preventing an iron frying pan from rusting is applying a coating of zinc. This process is also called galvanisation.

Applying grease(a) and applying paint(b) are also one of the ways to prevent iron frying pan from rusting but it is not the most best possible way as grease and paint can be eroded/removed while heating or cleaning iron frying pan but on the other hand coating of zinc will be sustained for a longer duration.

Q3 )

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

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

The Element is likely to be Calcium (Option a)

Calcium react with oxygen and gives calcium oxide which has a high melting point of 2,572 celsius and it is also soluble in water

Let us look at other options :
Option b - carbon reacts with oxygen to give carbon dioxide which is a gas. So, this option is wrong.
Option c - silicon reacts with oxygen to form silicon oxide which is insoluble in water .So, the option is wrong
Option d - iron reacts with oxygen to form iron(iii) oxide which is insoluble in water.So,the option is wrong

Q4 )

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.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Food cans are coated with tin and not zinc because zinc is more reactive than tin. So, option c is correct.

We should not use zinc in food cans as they are more reactive and might react with food items present in containers and make them unhealthy and not good for eating.

Q5 )

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 in distinguishing between metals and non-metals.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

(a)
If the substance can be hammered to convert into sheets then it is metal if it is broken into pieces then it is non-metal. Set up the arrangement using bulb, battery, wire and switch as shown in figure. Place the substance between Point A and B if the bulb starts glowing then the substance is a Metal otherwise it is non-metal because metals are good conductor of electricity.
(b)
Generally above methods can be used to identify metals and non-metals. But there are some exceptions also for example Sodium is metal which is not malleable in fact it is brittle. Graphite allotrope of non-metal carbon is a good conductor of electricity.

Q6 )

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

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Those oxides that behave as both acidic and basic oxides are called amphoteric oxides. Examples: aluminium oxide (Al2O3), zinc oxide (ZnO)

Q7 )

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

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Iron and aluminium will displace hydrogen from dilute acids as they more reactive then hydrogen. Mercury and copper cannot displace hydrogen from dilute acids as they are less reactive than hydrogen.

Q8 )

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

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

: During electrolytic refining, impure metal is made anode and a thin strip of pure metal M is made cathode and the electrolyte used is the soluble salt of Metal M which is to be refined.
For example -if impure copper needs to be refine then set up is in the way

Q9 )

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 ?
• (ii) moist litmus paper ?
• (d)Write a balanced chemical equation for the reaction taking place.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

(a)
(i) There will be no action on dry litmus paper.
(ii) The colour of litmus paper will turn red because sulphur is a non-metal and the oxides of non-metal are acidic in nature.

(b)
$S\left(s\right)+{O}_{2}\left(g\right)?S{O}_{2}\left(g\right)$

Q10 ) State two ways to prevent the rusting of iron.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Two ways to prevent the rusting of iron are:

Oiling, greasing, or painting: By applying oil, grease, or paint, the surface becomes water proof and the moisture and oxygen present in the air cannot come into direct contact with iron. Hence, rusting is prevented.

Galvanisation:An iron article is coated with a layer of zinc metal, which prevents the iron to come in contact with oxygen and moisture. Hence, rusting is prevented.

Q11 )

What type of oxides are formed when non-metals combine with oxygen?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

When non-metals are combined with oxygen then neutral or acidic oxides are formed. Examples of acidic oxides are NO2, SO2 and examples of neutral oxides are NO, CO etc.

Q12 )

Give reasons :

• (a) Platinum, gold and silver are used to make jewellery.
• (b) Sodium, potassium and lithium are stored under oil.
• (c) Aluminium 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.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

• (a) Platinum, gold and silver are used to make jewellery because these are low reactive metals so rarely corrosion occur (In silver) and hence do not lost their shine and lustre.
• (b)Sodium, potassium, and lithium are very reactive metals and react very vigorously with air as well as water.Therefore, they are kept immersed in kerosene oil in order to prevent their contact with air and moisture.
• (c) Though aluminium is a highly reactive metal, it is resistant to corrosion. This is because aluminium reacts with oxygen present in air to form a thin layer of aluminium oxide. This oxide layer is very stable and prevents further reaction of aluminium with oxygen. Also, it is light in weight and a good conductor of heat. Hence, it is used to make cooking utensils.
• (d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction because metals can be easily extracted from their oxides rather than from their carbonates and sulphides.
• Q13 ) 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.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Copper reacts with moist carbon dioxide in air to form copper carbonate and as a result, copper vessel loses its shiny brown surface forming a green layer of copper carbonate. The citric acid present in the lemon or tamarind neutralises the basis copper carbonate and dissolves the layer. That is why, tarnished copper vessels are cleaned with lemon or tamarind juice to give the surface of the copper vessel its characteristic lustre.

Q14 ) Differentiate between metal and non-metal on the basis of their chemical properties

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

metals Non-metals
The density of metals is usually high. Nonmetals are poor conductors of heat and electricity. Graphite and Gas carbon are exceptions.
Metals are malleable and ductile. Unlike metals, nonmetals aren’t malleable and ductile.
Metals form an alloy with other metals or non – metals. Nonmetals react more with metals than with nonmetals.
Some metals react with air and corrode. For e.g. Iron. Usually, nonmetals react with other nonmetals in high temperature.
Metals are good conductors of heat and electricity. Lead is an exception. Most nonmetals do not react with air in room temperature.
Generally, metals are in a solid state at room temperature. Except for Mercury. Mercury is in a liquid state. White phosphorus is the only nonmetal that reacts with air to form its oxide by burning.
Many metals produce metal oxide by burning in the oxygen of the air. Highly reactive metals react violently when they’re burnt in oxygen. Usually, nonmetals do not react with water. Except for Chlorine, chlorine dissolves in water to form an acidic solution.
Metals like sodium and potassium are stored in oil as they react with air in seconds. They’re highly reactive metals.
Less reactive metals like gold, silver, platinum, etc do not tarnish easily. They stay shiny and lustrous.
Nonmetals have a low density.
Metals produce metal oxide and hydrogen gas while reacting with water. They do not form alloys. However, nonmetals like carbon, silicon and phosphorous.
Soluble metal oxides dissolve in water and create metal hydroxide. Nonmetals exist in all states of matter at room temperature.
Not all metals react with water. However, highly reactive metals like sodium and potassium react with water violently and an exothermic reaction takes places where the hydrogen immediately catches fire. Salt and hydrogen are produced when a metal reacts with an acid.
Generally, a metal displaces a less reactive metal in a metal salt solution.
Different nonmetals have different reactions. Chlorine is the most reactive metal in the halogen family i.e. Chlorine (Cl), Bromine (Br), Iodine (I), and Fluorine (F). The reactivity order of the halogen family is Cl > Br > I.
Therefore, Chlorine (Cl) can displace Bromine (Br) and Iodine (I) from solutions of bromides (NaBr) and Iodides (NaI).
Ionic solids are formed when nonmetals with high electronegativity react with alkali and alkaline earth metals.

Q15 ) 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?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Aqua regia is a freshly prepared mixture of concentrated hydrochloric acid and concentrated nitric acid in the ration 3:1.It can dissolve gold. It is a corrosive fuming liquid. That's why it is used to clean gold and platinum too. And after cleaning gold along with impurities, it will shine but its weight become slightly less.

Q16 ) Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Copper does not react with cold water, hot water, or steam. However, iron reacts with steam. If the hot water tanks are made of steel (an alloy of iron), then iron would react vigorously with the steam formed from hot water. $3Fe+4{H}_{2}O?F{e}_{3}{O}_{4}+{H}_{2}O$
That is why copper is used to make hot water tanks, and not steel.

## NCERT solutions for class 10 Science Chapter 3 Metals And Non Metals Intext Exercise

Q1 ) 1 Give an example of a metal which

1. is a liquid at room temperature.
2. can be easily cut with a knife.
3. is the best conductor of heat.
4. is a poor conductor of heat.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

1. Mercury
2. Sodium
3. Silver
4. Bismuth

Q2 ) Explain the meanings of malleable and ductile.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Malleable :

It is the property of metals, in which the metal can be shaped by pounding with a hammer or by pressure from rollers..

Ductile:

Ductility is said to be the property of a material to be stretched and drawn into thin wires without getting damaged.

Q3 ) Why is sodium kept immersed in kerosene oil ?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Sodium reacts so vigorously with oxygen and moisture at room temperature that it catches fire when kept in open.But, it neither reacts nor dissolves if kept in kerosene so, Sodium is kept immersed in kerosene.

Q4 ) Write equations for the reactions of

1. iron with steam.
2. calcium and potassium with water.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

1. $2Fe\left(s\right)+3{H}_{2}O\left(g\right)$

$?$

$F{e}_{2}{O}_{3}\left(s\right)+3{H}_{2}\left(g\right)$

2. Calcium with water:

$Ca\left(s\right)+2{H}_{2}O\left(l\right)$

$?$

$Ca\left(OH{\right)}_{2}\left(aq\right)+{H}_{2}\left(g\right)$

Potassium with water:

$2K\left(s\right)+2{H}_{2}O\left(l\right)$

$?$

$2KOH\left(aq\right)+{H}_{2}\left(g\right)+heatenergy$

Q5 ) 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.

1. Which is the most reactive metal ?
2. What would you observe if B is added to a solution of Copper (II) sulphate ?
3. Arrange the metals A, B, C and D in the order of reactivity.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

1. B is the most reactive metal.
2. B will displace copper from copper sulphate and show a displacement reaction.
3. Metal B> Metal A > Metal C > Metal D

Q6 ) Which gas is produced when dilute hydrochloric acid is added to a reactive metal ? Write the chemical reaction when iron reacts with dilute ${H}_{2}S{O}_{4}$.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

When a reactive metal reacts with dilute hydrochloric acid hydrogen gas is produced along with salt of the metal.The reactive metal displaces the hydrogen from acid and releases hydrogen gas.

$Fe\left(s\right)+dil.{H}_{2}S{O}_{4}\left(aq\right)$

$?$

$FeS{O}_{4}\left(aq\right)+{H}_{2}\left(g\right)$

Q7 ) What would you observe when zinc is added to a solution of iron (II) sulphate ? Write the chemical reaction that takes place.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

When zinc is added to a solution of iron (ll) sulphate it displaces iron from iron(II) sulphate.The reaction is as follows:

$Zn\left(s\right)+FeS{O}_{4}\left(aq\right)$

$?$

$ZnS{O}_{4}\left(aq\right)+Fe\left(s\right)$

Q8 )

1. Write the electron-dot structures for sodium, oxygen and magnesium.
2. Show the formation of $N{a}_{2}OandMgO$ by the transfer of electrons.
3. What are the ions present in these compounds ?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

(i)

(iii)

$N{a}_{2}O?N{a}^{+}and{O}_{2}^{?}$ $MgO?M{g}_{2}^{+}and{O}_{2}^{?}$

Q9 ) Why do ionic compounds have high melting points ?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Oppositely charged ions are present in ionic compounds and are bounded by a strong electrostatic force of attraction.This is because a considerable amount of energy is required to break this force of attraction. That’s why ionic compounds have high melting points.

Q10 ) Define the following terms :
(i) Mineral

(ii) Ore

(iii) Gangue

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

(i)Mineral: The elements or compounds, which occur naturally in the earth’s crust are known as minerals
(ii)Ore: Minerals from which the metals can be extracted profitably are called ores.

(iii)Gangue: Gangue is the commercially worthless material that surrounds, or is closely mixed with a wanted mineral in an ore deposit such as soil, sand, etc.

Q11 ) Name two metals which are found in nature in the free state.

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Gold and Platinum are found in nature in free state.

Q12 ) What chemical process is used for obtaining a metal from its oxide ?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

A metal can be extracted from its oxide by the process of Reduction.

Q13 ) Metallic oxides of zinc, magnesium and copper were heated with the following metals :

In which cases will you find displacement reactions taking place ?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

A displacement reaction takes place when a more reactive metal displaces a less reactive metal from its oxide.Here we have magnesium as the most reactive metal whereas copper as the least reactive metal.So the table is as follows:

Q14 ) Which metals do not corrode easily ?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals

Metals which have low reactivity are not affected by air, moisture or ordinary chemicals,therefore, they do not corrode easily. Metals like platinum, silver, gold etc. do not corrode easily.

Q15 ) What are alloys ?

NCERT Solutions for Class 10 Science Chapter 3 Metals And Non Metals