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Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements

Samacheer Kalvi 10th Science Periodic Classification of Elements Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
The number of periods and groups in the periodic table are:
(a) 6, 16
(b) 7, 17
(c) 8, 18
(d) 7, 18
Answer:
(d) 7, 18

Question 2.
The basis of modem periodic law is ____.
(a) atomic number
(b) atomic mass
(c) isotopic mass
(d) number of neutrons.
Answer:
(a) atomic number

Question 3.
……….. group contains the member of the halogen family.
(a) 17th
(b) 15th
(c) 18th
(d) 16th
Answer:
(a) 17th

Question 4.
_______ is a relative periodic property.
(a) atomic radii
(b) ionic radii
(c) electron affinity
(d) electronegativity.
Answer:
(b) ionic radii

Question 5.
Chemical formula of rust is:
(a) Fe0.xH₂O
(b) Fe04.xH₂O
(c) Fe₂O₃. xH₂O
(d) FeO
Answer:
(c) Fe₂O₃. xH₂O

Question 6.
In the aluminothermic process the role of Al is:
(a) oxidizing agent
(b) reducing agent
(c) hydrogenating agent
(d) sulphurising agent
Answer:
(b) reducing agent

Question 7.
The process of coating the surface of the metal with a thin layer of zinc is called ____.
(a) painting
(b) thinning
(c) galvanization
(d) electroplating.
Answer:
(c) galvanization

Question 8.
Which of the following inert gas has electrons in the outermost shell?
(a) He
(b) Ne
(c) Ar
(d) Kr
Answer:
(a) He

Question 9.
Neon shows zero electron affinity due to ____.
(a) stable arrangement of neutrons
(b) stable configuration of electrons
(c) reduced size
(d) increased density.
Answer:
(b) stable configuration of electrons

Question 10.
……….. is an important metal to form amalgam.
(a) Ag
(b) Hg
(c) Mg
(d) Al
Answer:
(b) Hg

II. Fill in the blanks:

1. If the electronegativity difference between two bonded atoms in a molecule is greater than 1.7, the nature of bonding is ………..
2. …………. is the longest period in the periodical table.
3. ………… forms the basis of modern periodic table.
4. If the distance between two Cl atoms in Cl₂ molecule is 1.98 Å, then the radius of Cl atom is ………..
5. Among the given species A^– A⁺, and A, the smallest one in size is ……….
6. The scientist who propounded the modern periodic law is …………
7. Across the period, ionic radii ………… (increases,decreases).
8. ……….. and ………… are called inner transition elements.
9. The chief ore of Aluminium is ………….
10. The chemical name of rust is ………….
Answer:
1. ionic
2. 6th (sixth) period
3. Atomic number
4. 0.99 Å
5. A⁺
6. Dimitri Mendeleev
7. decreases
8. Lanthanides, Actinides
9. bauxite
10. hydrated ferric oxide

III. Match the following:

Answer:
A. (ii)
B. (v)
C. (iv)
D. (iii)
E. (i)

IV. True or False: (If false give the correct statement)

1. Moseley’s periodic table is based on atomic mass.
2. Ionic radius increases across the period from left to right.
3. All ores are minerals; but all minerals cannot be called as ores.
4. Aluminium wires are used as electric cables due to their silvery white colour.
5. An alloy is a heterogenous mixture of metals.
Answer:
1. False – Moseley’s periodic table is based on atomic number.
2. True
3. True
4. False – Aluminium wires are used as electric cables because it is a good conductor of heat and electricity.
5. False – An alloy is an homogeneous mixture of metals.

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: The nature of bond in HF molecule is ionic.
Reason: The electronegativity difference between H and F is 1.9.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: Magnesium is used to protect steel from rusting.
Reason: Magnesium is more reactive than iron.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 3.
Assertion: An uncleaned copper vessel is covered with greenish layer. Reason: copper is not attacked by alkali.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

VI. Short answer questions:

Question 1.
A is a reddish brown metal, which combines with O₂ at < 1370 K gives B, a black coloured compound. At a temperature > 1370 K, A gives C which is red in colour. Find A, B and C with reaction.
Answer:
(A) is a reddish brown metal – Copper

A – Copper; B – Cupric oxide; C – Cuprous oxide.

Question 2.
A is a silvery white metal. A combines with O₂ to form B at 800°C, the alloy of A is used in making the aircraft. Find A and B.
Answer:
A – Silvery white metal – Aluminium

The alloys of aluminium, Duralumin and Magnalium are used in making the aircraft.
A – Aluminium; B – Aluminium oxide.

Question 3.
What is rust? Give the equation for the formation of rust.
Answer:
When iron is exposed to moist air, it forms a layer of brown hydrated ferric oxide on its surface. This compound is known as rust and the phenomenon of formation of rust is known as rusting.
4Fe + 3O₂ + xH₂O → 2Fe₂O₃. xH₂O (Rust).

Question 4.
State two conditions necessary for rusting of iron.
Answer:
(i) The presence of water and oxygen is essential for the rusting of iron.
(ii) Impurities in the iron, the presence of water vapour, acids, salts and CO₂ speeds up rusting.

VII. Long answer questions:

Question 1.
(a) State the reason for addition of caustic alkali to bauxite ore during purification of bauxite.
Answer:
Caustic alkali is added to bauxite, to dissolve bauxite ore and obtain a solution of sodium aluminate.

(b) Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition.
Answer:
CaF₂ (Fluorspar) is added along with cryolite and alumina. It is added to reduce the high melting point of the electrolyte.

Question 2.
The electronic configuration of metal A is 2, 8, 18, 1.
The metal A when exposed to air and moisture forms B a green layered compound. A with con. H₂SO₄ forms C and D along with water. D is a gaseous compound. Find A, B, C and D.
Answer:
Metal (A) with electronic configuration- 2, 8, 18, 1 is copper.
2Cu + O₂ + CO₂ + H₂O → CuCO₃. Cu(OH)₂ (B)
Copper carbonate (Green layer)

(A) – Copper (Cu)
(B) – Copper Carbonate (CuCO₃. Cu(OH)₂)
(C) – Copper Sulphate (CuSO₄)
(D) – Sulphur dioxide (SO₂)

Question 3.
Explain the smelting process.
Answer:
The roasted ore of copper is mixed with powdered coke and sand and is heated in a blast furnace to obtain matte (Cu₂S + FeS) and slag. The slag is removed as waste.
2 FeS + 3O₂ → 2 FeO + 2 SO₂
2 Cu₂S + 3O₂ → 2 Cu₂O + 2SO₂
Cu₂O + FeS → Cu₂S + FeO
FeO + SiO₂ → FeSiO₂ (slag)

VIII. HOT questions:

Question 1.
Metal A belongs to period 3 and group 13. A in red hot condition reacts with steam to form B. A with strong alkali forms C. Find A, B and C with reactions.
Answer:
Metal A belongs to Period 3 and Group 13. So metal ‘A’ is aluminium.
(A) in red hot condition reacts with steam to form ‘B’.

‘A’ with strong alkali forms ‘C’

(A) – Aluminium
(B) – Aluminium oxide
(C) – Sodium meta aluminate

Question 2.
Name the acid that renders aluminium passive. Why?
Answer:
Dilute or concentrated nitric acid (HNO₃) renders aluminium passive. Because nitric acid does not attack aluminium but it renders aluminium passive due to the formation of an oxide film on its surface.

Question 3.
(a) Identify the bond between H and F in HF molecule.
Answer:
Ionic, because the electronegativity difference is more than 1.7.

(b) What property forms the basis of identification?
Answer:
Electronegativity.

(c) How does the property vary in periods and in groups?
Answer:
In a period, from left to right the electronegativity increases because of the increase in the nuclear charge.
In a Group, from top to bottom, the electronegativity decreases because of the increase in size of the elements.

Samacheer Kalvi 10th Science Periodic Classification of Elements Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
The shortest period in the periodic table contains elements.
(a) 18
(b) 8
(c) 2
(d) 32
Answer:
(c) 2

Question 2.
Group number of carbon family is _____.
(a) 13
(b) 15
(c) 17
(d) 14.
Answer:
(d) 14.

Question 3.
The ore forming elements, chalcogens are present in ……… group of the modern periodic table.
(a) 18th
(b) 1st
(c) 2nd
(d) 16th
Answer:
(d) 16th

Question 4.
Valency of all the alkali metals is _____.
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(a) 1

Question 5.
The largest atom in the 2nd period of the periodic table is:
(a) Li
(b) Be
(c) F
(d) Ne
Answer:
(a) Li

Question 6.
The covalent radii of Hydrogen, if the distance between the Hydrogen nuclei of the molecule is 0.74 Å is:
(a) 1.58 Å
(b) \(\frac{0.74}{4}\) Å
(c) 0.37 Å
(d) 0.74 Å
Answer:
(c) 0.37 Å

Question 7.
Pick out the correct ionic radii in increasing order for the following species – Na, Cl, Na⁺, Cl^– _____.
(a) Na > Cl > Na⁺ > Cl^–
(b) Cl > Na > Na⁺ > Cl^–
(c) Cl^– > Na > Na⁺ > Cl
(d) Cl < Na⁺ < Cl^– < Na.
Answer:
(d) Cl < Na⁺ < Cl^– < Na.
Hint:
Na = 186 pm,
Cl = 91 pm,
Na⁺ = 116 pm,
Cl^– = 167 pm.

Question 8.
In the third period, the first ionization potential is of the order:
(a) Na > Al > Mg > Si > P
(b) Mg > Na > Si > P > Al
(c) Na < Al < Mg < Si < P
(d) Na < Al < Mg < Si < P
Answer:
(c) Na < Al < Mg < Si < P

Question 9.
Which one of the following is the least electronegative element?
(a) Bromine
(b) Chlorine
(c) Iodine
(d) Hydrogen
Answer:
(d) Hydrogen

Question 10.
Which is a widely used a scale to determine the electronegativity?
(a) Pauling scale
(b) Moseley scale
(c) Mendeleev scale
(d) none of these.
Answer:
(a) Pauling scale

Question 11.
Which one of the following orders of ionic radii is correct?
(a) H^– > H⁺ > H
(b) Na⁺ > F^– > O^2-
(c) F > O^2- > Na⁺
(d) None of these
Answer:
(d) None of these

Question 12.
The percentage of carbon in Pig iron is:
(a) < 0.25%
(b) 0.25 – 2%
(c) 2 – 4.5%
(d) > 5%
Answer:
(c) 2 – 4.5%

Question 13.
The chemical formula of clay is _____.
(a) Al₂O₃
(b) Al₂O₃.2H₂O
(c) Al₂O₃. 2SiO₂.2H₂O
(d) Al₂O₃. 2SiO₂.H₂O.
Answer:
(c) Al₂O₃. 2SiO₂.2H₂O

Question 14.
The temperature in the combustion zone is maintained at:
(a) 1500°C
(b) 400°C
(c) 1000°C
(d) 1380°C
Answer:
(a) 1500°C

Question 15.
Oil used in Froth floatation method is _____.
(a) pine oil
(b) natural oil
(c) crude oil
(d) Synthetic oil.
Answer:
(a) pine oil

Question 16.
The first most abundant metal present in the Earth crust is:
(a) Iron
(b) Aluminium
(c) Zinc
(d) Copper
Answer:
(b) Aluminium

Question 17.
……….. metal is used for making calorimeters.
(a) Copper
(b) Tin
(c) Mercury
(d) Iron
Answer:
(a) Copper

Question 18.
More reactive metal is _____.
(a) Zn
(b) Fe
(c) Ag
(d) Na.
Answer:
(d) Na.

Question 19.
The chief ore of Iron is:
(a) Magnesite
(b) Galena
(c) Cinnabar
(d) Haematite
Answer:
(d) Haematite

Question 20.
The metal which melts at room temperature is:
(a) Zinc
(b) Lead
(c) Gallium
(d) Tin
Answer:
(c) Gallium

Question 21.
Conversion of bauxite into alumina is _____.
(a) Hall’s process
(b) Alumino thermic process
(c) Baeyer’s process
(d) Bessemerisation process.
Answer:
(c) Baeyer’s process

Question 22.
………. metal can be cut with knife.
(a) Potassium
(b) Gallium
(c) Mercury
(d) Gold
Answer:
(a) Potassium

Question 23.
………. is not a good conductor of heat and electricity.
(a) Silver
(b) Tungsten
(c) Copper
(d) Aluminium
Answer:
(b) Tungsten

Question 24.
Electrolyte used in Hall’s process ______.
(a) Pure alumina + molten cryolite + fluorspar
(b) Pure alumina + molten bauxite + fluorspar
(c) Pure bauxite + molten cryolite + fluorspar
(d) Pure bauxite + molten Haematite + fluorspar.
Answer:
(a) Pure alumina + molten cryolite + fluorspar

Question 25.
The foaming agent used for froth floatation process is:
(a) Coconut oil
(b) Pine oil
(c) Sodium chloride
(d) Groundnut oil
Answer:
(b) Pine oil

Question 26.
Three elements A, B and C are having the electronic configuration Is² 2s¹, Is² 2s² and Is² 2s² 2p¹ respectively. Which element will have the lowest ionization energy?
(a) A
(b) B
(c) C
(d) B and C
Answer:
(a) A

Question 27.
Metal used in household utensils is ______.
(a) Al
(b) Co
(c) Fe
(d) Na.
Answer:
(a) Al

Question 28.
Which one of the following pair is a metalloid?
(a) Na and K
(b) F and Cl
(c) Cu and Hg
(d) Si and Ge
Answer:
(d) Si and Ge

Question 29.
The highly metallic element will have the configuration of:
(a) 2, 8, 7
(b) 2, 8, 8, 5
(c) 2, 8, 8, 1
(d) 2, 8, 2
Answer:
(c) 2, 8, 8, 1

Question 30.
The metal used in electroplating is ______.
(a) Cu
(b) Al
(c) Fe
(d) Co.
Answer:
(a) Cu

Question 31.
The flux which is used when the gangue present in the ore is acidic:
(a) Silica
(b) Calcium oxide
(c) Calcium silicate
(d) Cuprous sulphide
Answer:
(b) Calcium oxide

Question 32.
Matte is a mixture of:
(a) Cu₂O + Cu₂S
(b) Cu₂O + FeS
(c) Cu₂S + FeS
(d) Cu₂O + PbS
Answer:
(c) Cu₂S + FeS

Question 33.
Fe reacts with dilute nitric acid in cold condition to give ______.
(a) Ferrous nitride
(b) Ferrous nitrate
(c) Ferric nitride
(d) Ferric nitrate.
Answer:
(b) Ferrous nitrate

Question 34.
In the brass alloy, which is solvent?
(a) Zn
(b) Co
(c) Ag
(d) Cu.
Answer:
(d) Cu.

II. Fill in the blanks:

1. The major component of the matte is ………….
2. The modern periodic table is based on ………..
3. The valency of alkali metals is …………
4. The unreactive elements are present in group ………..
5. In the 2nd period, the smallest atom is ……….
6. The size of a cation is ………… than the neutral atom.
7. ……….. is the unit of ionization energy.
8. The ionization energy ……… down the group in the periodic table.
9. The electron affinities of noble gases are …………
10. ………. is the process of extracting the ore from the Earth’s crust.
11. Galena is the ore of …………..
12. The silvery white metal which is a good conductor of heat and electricity is …………
13. The slag formed during Bessemerisation process is ………….
14. Blister copper contains ………. percentage of copper.
15. Haematite ore is concentrated by ……….. washing.
Answer:
1. Cu₂S
2. atomic number
3. one
4. 18
5. Neon
6. smaller
7. KJ/mol
8. decreases
9. zero
10. Mining
11. lead
12. aluminium
13. Iron silicate or FeSiO₃
14. 98%
15. hydraulic

III. Match the following:

Question 1.
Match the column I with column II.

Answer:
A. (iv)
B. (v)
C. (i)
D. (ii)
E. (iii)

Question 2.
Match the column I with column II.

Answer:
A. (ii)
B. (iv)
C. (v)
D. (iii)
E. (i)

Question 3.
Match the column I with column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (i)
E. (ii)

Question 4.
Match the column I with column II.

Answer:
A. (v)
B. (iv)
C. (ii)
D. (iii)
E. (i)

IV. True or false. (If false give the correct statement)

1. Alkali metals are generally extracted by the electrolysis of their ores in fused state.
2. Every mineral is an ore but every ore is not a mineral.
3. Slag is a product formed during smelting by combination of flux and impurities.
4. Reactive metals occur in native state.
5. Malachite is a sulphide ore of copper.
6. Lanthanides are present in the 6th group of the periodic table.
7. Atomic radius increases as we go across the period due to increase in size.
8. As the positive charge increases, the size of the cation decreases.
9. If the difference in electronegativity is greater than 1.7, the bond is considered to be covalent.
10. Siderite is the carbonate ore of calcium.
Answer:
1.True
2. True
3. True
4. False – Reactive metals always occur in the combined state.
5. False – Malachite is the carbonate ore of copper.
6. False – Lanthanides are present in the 6th period of the periodic table.
7. False – Atomic radius increases as we go across the period due to decrease in size.
8. True
9. False – If the difference in electronegativity is greater than 1.7, the bond is considered to be ionic.
10. False – Siderite is the carbonate ore of Iron.

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: Zinc blende is concentrated by Froth floatation process.
Reason: Zinc blende is a sulphide ore.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: In thermite welding, aluminium powder and Fe₂O₃ are used.
Reason: Aluminium powder is a strong reducing agent.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 3.
Assertion: To design the body of an aircraft, aluminium alloys are used.
Reason: Aluminium becomes passive when it is treated with dil or con.HNO₃
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

Question 4.
Assertion: Tinstone and the impurity wolframite are seperated by magnetic separation.
Reason: Tinstone is magnetic and wolframite is non-magnetic in nature.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 5.
Assertion: Bauxite is purified by leaching.
Reason: Bauxite undergoes thermal decomposition.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(b) Assertion is correct, Reason is wrong.

VI. Short answer questions:

Question 1.
State the modern periodic law.
Answer:
The physical and chemical properties of the elements are the periodic function of their atomic number.

Question 2.
‘X’ is a silvery white metal. X reacts with O₂ to form Y. The same compound is obtained from the metal on reaction with steam with the liberation of hydrogen gas. Identify X and Y.
Answer:
(i) Silvery white metal ‘X’ is Aluminium.
(ii) It reacts with O₂ to form ‘Y’

(iii) Y can also be obtained on reaction with steam with the liberation of H₂.

Question 3.
Write any four characteristics of periods.
Answer:

• In a period, the electrons are filled in the same valence shell of all elements.
• As the electronic configuration changes along the period, the chemical properties of the elements also change.
• The atomic size of the elements in a period decreases from left to right
• In a period, die metallic character of the element decreases, while their non-metallic character increases.

Question 4.
Write the Principle of Hydraulic washing.
Answer:
The difference in the densities or specific gravities of the ore and the gangue is the main principle behind this method.

Question 5.
What are coinage metals?
Answer:
Copper, silver and gold are called coinage metals, as they are used in making coins and jewellery.

Question 6.
How will you separate tinstone from wolframite?
Answer:
Magnetic separation method. Tinstone is magnetic in nature.
Method: The crushed ore is placed over a conveyer belt which rotates around two metal wheels, one of which is magnetic. The magnetic particles are attracted to the magnetic wheel and fall separately apart from the non¬magnetic particles.

Question 7.
What are ores?
Answer:
The mineral from which a metal can be readily and economically extracted on a large scale is said to be ore.
eg. Bauxite Al₂O₃.2H₂O is the ore of Aluminium

Question 8.
Define electronegativity.
Answer:
It is the tendency of an element in a covalent bond to attract the shared pair of electrons towards itself. It is a relative property.

Question 9.
In what period and group will an element with z = 118 will be present?
Answer:
Elements with z = 118 will be present in Period number ‘7’ and Group number 18.

Question 10.
Why flux is added during metallurgy?
Answer:
Flux is the substance added to the ore to reduce the fusion temperature and to remove impurities.
e.g. CaO, SiO₂

Question 11.
State the trends in the electronegativity in a Group and period.
Answer:
In a Group: Electronegativity decreases in a group because of the increased number of energy levels.
In a Period: The electronegativity increases because the increase in the nuclear charge.

Question 12.
Write a note about smelting.
Answer:
Smelting is a process of reducing the roasted metallic oxide to metal in a molten condition. In this process, impurities are removed by the addition of flux as slag.

Question 13.
Write the formula of the ores of Aluminium.
Answer:

Question 14.
Explain the action of Aluminium with air.
Answer:
On heating at 800°C, aluminium bums in the air very brightly forming its oxide and nitride.
4Al + 3O₂ → 2Al₂O₃ (Aluminium oxide)
2Al + N₂ → 2AlN (Aluminium nitride).

Question 15.
What happen when Aluminium reacts with steam?
Answer:
When steam is passed over red hot aluminium, H₂ gas is evolved.

Question 16.
Write the reaction of Aluminium with Sodium hydroxide?
Answer:

Question 17.
Explain the electrolytic refining of copper.
Answer:
Cathode: A thin plate of pure copper metal.
Anode: A block of impure copper metal.
Electrolyte: Copper sulphate solution + dilute H₂SO₄
When an electric current is passed through the electrolytic solution, pure copper gets deposited at the cathode and the impurities are settled at the bottom of the anode as anode mud.

Question 18.
Mention the uses of Aluminium.
Answer:
Aluminium is used in

1. household utensils
2. electrical cable industry
3. making aeroplanes and other industrial machine parts.

Question 19.
What are the methods employed to make an alloy?
Answer:

1. By fusing the metals together. Eg: Brass is made by melting zinc and copper.
2. By compressing finely divided metals. Eg: wood mexai.

Question 20.
Write the components of wood metal.
Answer:
Wood metal is an alloy of Lead, Tin, Bismuth and Cadmium.

Question 21.
What are the uses of copper?
Answer:

• Copper is used in manufacturing electric cables and other electric appliances.
• Copper is used for making utensils, containers, calorimeters and coins.
• Copper is used in electroplating.
• Copper is alloyed with gold and silver for making coins and jewels.

Question 22.
Give example for non-ferrous copper and aluminium alloys. Non-ferrous copper alloys: Brass (Cu, Zn), Bronze (Cu, Sn)
Answer:
Non-ferrous aluminium alloys: Duralumin (Al, Mg, Cu, Mn), Magnalium (Al, Mg)

Question 23.
How is rust formed?
Answer:
When iron is exposed to moist air, it forms a layer of brown hydrated Ferric oxide on its surface. This compound is known as rust.
4Fe + 3O₂ + xH₂O → 2Fe₂O₃. xH₂O (Rust).

Question 24.
Why are the alloys prepared?
Answer:

1. To modify appearance and colour.
2. To modify chemical activity.
3. To lower the melting point.
4. To increase hardness and tensile strength.
5. To increase resistance to electricity.

Question 25.
Define corrosion.
Answer:
Corrosion is the gradual destruction of metals by chemical or electrochemical reaction with the environment.

Question 26.
What are alloys? How are they prepared?
Answer:

• An alloy is a homogeneous mixture of a metal with other metals or with non-metals that are fused together. e.g. Brass is an alloy of zinc (solute) in copper (solvent)
• Alloys are prepared by fusing the metals together.
• Alloys are prepared by compressing finely divided metals one over the other.

Question 27.
Which is known as Wet corrosion or Electrochemical corrosion?
Answer:
The corrosive action in the presence of moisture is called wet corrosion. It occurs as a result of electrochemical reaction of metal with water or aqueous solution of salt or acids or bases.

Question 28.
Write a note on Cathodic protection.
Answer:
It is the method of controlling corrosion of a metal surface protected is coated with the metal which is easily corrodible. The easily corrodible metal is called Sacrificial metal to act as anode ensuring cathodic protection.

Question 29.
What are the methods used to prevent corrosion?
Answer:
Corrosion of metals is prevented

• by coating with paints
• by coating with oil and grease
• by alloying with other metals
• by the process of galvanization
• by electroplating
• by sacrificial protection

Question 30.
A reddish brown metal ‘A’ reacts with dil.HCl in the presence of O₂ and forms the compound ‘B’. ‘B’ can also be prepared by heating the metal A with Cl₂. Identify A and B.
Answer:
Reddish brown metal ‘A’ is copper.
(A) reacts with dil.HCl in the presence of O₂ and forms CuCl₂ which is ‘B’.

(B) can also prepared by the action of Cl₂.

Question 31.
Write the uses of copper.
Answer:

1. It is extensively used in manufacturing electric cables and other electric appliances.
2. It is used for making utensils, containers, calorimeters and coins.
3. It is used in electroplating.
4. It is alloyed with gold and silver for making coins and jewels.

Question 32.
Write the name and formula of the ores of iron.
Answer:

Question 33.
Define periodicity.
Answer:
The electronic configurations of elements help us to explain the periodic recurrence of physical and chemical properties. Anything which repeats itself after a regular interval is called periodic and this behaviour is called periodicity.

Question 34.
What happens in the combustion zone during the extraction of iron.
Answer:
The temperature in the combustion zone is 150°C. In this region coke bums 02 to form CO₂, when the charge comes in contact with a hot blast of air.

Question 35.
Explain the reactions taking place in the reduction zone.
Answer:
In the upper region of reduction zone, the temperature is at 400°C. In this region CO reduces ferric oxide to form spongy iron.

Question 36.
Define Metallic radius.
Answer:
It is defined as half the distance between the nuclei of adjacent metal atoms.

Question 37.
Complete the following reactions.

1. 4Fe + 10HNO₃ → 4Fe(NO₃)₂ + ………. + 3H₂O
2. 2Fe + 6H₂SO₄ → Fe₂(SO₄)₃ + ………. + 6H₂O

Answer:

1. NH₄NO₃
2. 3SO₂

Question 38.
What happens when steam is passed over red hot iron?
Answer:
When steam is passed over red hot iron magnetic oxide is formed.
3Fe + 4H₂O (steam) → Fe₃O₄ + 4H₂↑

Question 39.
Define Electron affinity.
Answer:
Electron affinity is the amount of energy released when a gaseous atom gains an electron to form its anion. It is also measured in kJ / mol.

Question 40.
Complete the table.
Answer:

Question 41.
Define Metallurgy.
Answer:
Metallurgy is a science of extracting metals from their ores and modifying the metals into alloys for various uses, based on their physical and chemical properties and their structural arrangement of atoms.

Question 42.
Write a short note on leaching or chemical process.
Answer:
This method is employed when the ore is in a very pure form. The ore is treated with a suitable reagent such that the ore is soluble in it but the impurities are not. The impurities are removed by filtration. The solution of the ore, ie., the filtrate is treated with a suitable reagent which precipitates the ore.
E.g. Bauxite Al₂O₃.2H₂O, the ore of aluminium.

Question 43.
Relate all the four columns of the table with their unique properties.
Answer:

Question 44.
Guess Who I am?
(i) I am preserved in Kerosene.
Answer:
Sodium

(ii) My ore is leached with NaOH.
Answer:
Aluminium

(iii) I sacrifice myself to protect my friend Iron.
Answer:
Magnesium

(iv) I am being used in propellers
Answer:
Nickel steel

Question 45.
Explain the method of making alloys.
Answer:

• By fusing the metals together. E.g. Brass is made by melting zinc and copper.
• By compressing finely divided metals. E.g. Wood metal: an alloy of lead, tin, bismuth and cadmium powder is a fusible alloy.

Question 46.
Write the differences between a mineral and a ore.
Answer:

VII. Long answer questions:

Question 1.
Write the reactions taking place during Bessemerisation of copper.
Answer:
2 FeS + 3O₂ → 2FeO + 2SO₂↑

2Cu₂S + 3O₂ → 2 Cu₂O + 2 SO₂↑
2Cu₂O + Cu₂S → 6 Cu + SO₂↑

Question 2.
How do electronegativity values help to find out the nature of bonding between atoms?
Answer:

• If the difference in electronegativity between two elements is 1.7, the bond has 50% ionic character and 50 % covalent character.
• If the difference is less than 1.7, the bond is considered to be covalent.
• If the difference is greater than 1.7, the bond is considered to be ionic.

Question 3.
Explain Froth floatation with diagram.
Answer:
Principle: This process depends on the preferential wettability of the ore with oil (pine oil) and the gangue particles by water. Lighter ores, such as sulphide ores, are concentrated by this method. Eg: Zinc blende (ZnS).

Question 4.
Explain the Baeyer’s process of conversion of Bauxite into alumina.
Answer:
(i) Bauxite ore is finely ground and heated under pressure with a solution of concentrated caustic soda solution at 150°C to obtain sodium meta aluminate.
(ii) On diluting sodium meta aluminate with water, a precipitate of aluminium hydroxide is formed.
(iii) The precipitate is filtered, washed, dried and ignited at 1000°C to get alumina.

Question 5.
Explain the Hall’s Process of electrolytic reduction of alumina with diagram.
Answer:
Hall’s Process:
Aluminium is produced by the electrolytic reduction of fused alumina (Al₂O₃) in the electrolytic cell.
Cathode : Iron tank linked with graphite
Anode : A bunch of graphite rods suspended in molten electrolyte.
Electrolyte : Pure alumina + molten cryolite + fluorspar (fluorspar lowers the fusion temperature of electrolyte)

Temperature: 900 – 950 °C
Voltage used: 5 – 6 V
Overall reaction: 2 Al₂O₃ → 4 Al + 3O₂↑

Question 6.
Write the reaction involved in the middle region of blast furnace during the extraction of iron.
Answer:
The Middle Region (Fusion Zone): The temperature prevails at 1000°C. In this region, CO₂ is reduced to CO.

Limestone decomposes to calcium oxide and CO₂.

These two reactions are endothermic due to absorption of heat. Calcium oxide combines with silica to form calcium silicate slag.
CaO + SiO₂ → CaSiO₃

Question 7.
What are the three different types of iron? Write their uses.
Answer:
(i) Pig iron (Iron with 2-4.5% of carbon): It is used in making pipes, stoves, radiators, railings, manhole covers and drain pipes.
(ii) Steel (Iron with < 0.25% of carbon): It is used in the construction of buildings, machinery, transmission cables and T. V towers and in making alloys.
(iii) Wrought iron (Iron with 0.25-2% of wraught carbon): It is used in making springs, anchors and electromagnets.

Question 8.
What is corrosion? Write the chemistry behind the formation of rust.
Answer:
(i) The slow and steady destruction of a metal by chemical or electro chemical reaction with the environment.
(ii) When the surface of iron is exposed to moisture and other gases present in the atmosphere, the following chemical reaction takes place.
Fe → Fe²⁺ + 2e^–
O₂ + 2H₂O + 4e^– → 4OH^–
O₂ + 4H⁺ + 4e^– → 2H₂O
The Fe²⁺ ions are oxidised to Fe³⁺ ions.
The Fe³⁺ ions combine OH^– ions to form Fe(OH)₃. This becomes rust which is hydrated ferric oxide with the formula Fe₂O₃.xH₂O. It is a reddish brown substance.

Question 9.
Explain the methods of preventing corrosion.
Answer:
(i) Alloying : The metals can be alloyed to prevent the process of corrosion. Eg: Stainless Steel

(ii) Surface Coating : It involves application of a protective coating over the metal. It is of the following types:
(a) Galvanization: It is the process of coating zinc on iron sheets by using electric current.
(b) Electroplating: It is a method of coating one metal over another metal by passing electric current.
(c) Anodizing: It is an electrochemical process that converts the metal surface into a decorative, durable and corrosion resistant. Aluminium is widely used for anodizing process.
(d) Cathodic Protection: It is the method of controlling corrosion of a metal surface protected is coated with the metal which is easily corrodible. The easily corrodible metal is called sacrificial metal to act as anode ensuring cathodic protection.

Question 10.
Discuss the main featured of Periods in the modern periodic table (or) long form of periodic table.
Answer:
The horizontal rows are called periods.There are seven periods in the periodic table.

1. First period (Atomic number 1 and 2): This is the shortest period. It contains only two elements (Hydrogen and Helium).
2. Second period (Atomic number 3 to 10): This is a short period. It contains eight elements (Lithium to Neon).
3. Third period (Atomic number 11 to 18): This is also a short period. It contains eight elements (Sodium to Argon).
4. Fourth period (Atomic number 19 to 36): This is a long period. It contains eighteen elements (Potassium to Krypton). This includes 8 normal elements and 10 transition elements.
5. Fifth period (Atomic number 37 to 54): This is also a long period. It contains 18 elements (Rubidium to Xenon). This includes 8 normal elements and 10 transition elements.
6. Sixth period (Atomic number 55 to 86): This is the longest period. It contains 32 elements (Caesium to Radon). This includes 8 normal elements, 10 transition elements and 14 inner transition elements (Lanthanides).
7. Seventh period (Atomic number 87 to 118): Like the sixth period, this period also accommodates 32 elements. Recently 4 elements have been included by IUPAC.

Question 11.
Discuss the main feature of Groups in the long form of periodic table.
Answer:
(i) The vertical columns in the periodic table starting from top to bottom are called groups. There are 18 groups in the periodic table.

(ii) Based on the common characteristics of elements in each group, they can be grouped as various families.

(iii) The Lanthanides and Actinides, which form part of Group 3 are called inner transition elements.

(iv) Except ‘group O’, all the elements present in each group have the same number of electrons in their valence shell and thus have the same valency. Eg: all the elements of group 1 have one electron in their valence shells (Is¹). So, the valency of all the alkali metals is ‘ 1’.

(v) As the elements present in a group have identical valence shell electronic configurations, they possess similar chemical properties.

(vi) The physical properties of the elements in a group such as melting point, boiling point and density vary gradually.

(vii) The atoms of the ‘group 0’ elements have stable electronic configuration in their valence shells and hence they are unreactive.

VIII. Hot Questions:

Question 1.
Why noble gases have zero electron affinity value?
Answer:
Noble gases show no tendency to accept electrons because the outers and p orbitals of noble gases are completely filled. No more electrons can be added to them and hence their electron affinities are zero.

Question 2.
Arrange the following ions in order of their increasing ionic radii.
Answer:
Li⁺, Mg²⁺, K⁺ Al³⁺
Al³⁺ < Li⁺ < Mg²⁺ < K⁺

Question 3.
Cationic radius is smaller than its corresponding neutral atom. Why?
Answer:
When a neutral atom lose one or more electrons it forms a cation.
Na → Na⁺ + e^–
The radius of this cation (r_Na+)is decreased than its parent atom (r_Na).
When an atom is charged to cation, the number of nuclear charges becomes greater than the number of orbital electrons. Florence the remaining electrons are more strongly attracted by the nucleus. Hence the cationic radius is smaller than its corresponding neutral atom.

Students can download 10th Science Chapter 7 Atoms and Molecules Questions and Answers, Notes, Samacheer Kalvi 10th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 7 Atoms and Molecules

Samacheer Kalvi 10th Science Atoms and Molecules Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
Which of the following has the smallest mass?
(a) 6.023 × 10²³ atoms of He
(b) 1 atom of He
(c) 2 g of He
(d) 1-mole atoms of He
Answer:
(b) 1 atom of He

Question 2.
Which of the following is a triatomic molecule?
(a) Glucose
(b) Helium
(c) Carbon dioxide
(d) Hydrogen.
Answer:
(c) Carbon dioxide
Hint:
(a) Glucose = C₆H₁₂O₆ (Polyatomic molecule)
(b) Helium = He (Monoatomic molecule)
(c) Carbon dioxide = CO₂ (Triatomic molecule)
(d) Hydrogen = H₂ (Diatomic molecule)
So, (c) is the correct answer.

Question 3.
The volume occupied by 4.4 g of CO₂ at S.T.P:
(a) 22.4 litre
(b) 2.24 litre
(c) 0.24 litre
(d) 0.1 litre
Answer:
(b) 2.24 litre

Question 4.
Mass of 1 mole of Nitrogen atom is _____.
(a) 28 amu
(b) 14 amu
(c) 28 g
(d) 14 g.
Answer:
(b) 14 amu
Hint: Atomic mass of Nitrogen is 14.00674 grams. It is equal to 1 mole of Nitrogen atoms.
So, answer (b) is correct.

Question 5.
Which of the following represents 1 amu?
(a) Mass of a C – 12 atom
(b) Mass of a hydrogen atom
(c) 1/12 th of the mass of a C – 12 atom
(d) Mass of O – 16 atom
Answer:
(c) 1/12 th of the mass of a C – 12 atom

Question 6.
Which of the following statement is incorrect?
(a) One gram of C – 12 contains Avogadro’s number of atoms.
(b) One mole of oxygen gas contains Avogadro’s number of molecules.
(c) One mole of hydrogen gas contains Avogadro’s number of atoms.
(d) One mole of electrons stands for 6.023 × 10²³ electrons.
Answer:
(a) One gram of C – 12 contains Avogadro’s number of atoms.
Hint: 12 g of Carbon contains 6.023 × 10²³ atoms,
1 g of Carbon contain \(\frac{6.023 \times 10^{23}}{12}\) = 5.018 × 10²² atoms and its is not Avogadro’s number of atoms.
So (a) is the incorrect statement.

Question 7.
The volume occupied by 1 mole of a diatomic gas at S.T.P is:
(a) 11.2 litre
(b) 5.6 litre
(c) 22.4 litre
(d) 44.8 litre
Answer:
(c) 22.4 litre

Question 8.
In the nucleus of ₂₀Ca⁴⁰, there are
(a) 20 protons and 40 neutrons
(b) 20 protons and 20 neutrons
(c) 20 protons and 40 electrons
(d) 40 protons and 20 electrons
Answer:
(b) 20 protons and 20 neutrons

Question 9.
The gram molecular mass of oxygen molecule is_____.
(a) 16 g
(b) 18 g
(c) 32 g
(d) 17 g.
Answer:
(c) 32 g
Hint: By definition, the gram molecular mass of oxygen molecule O₂ is 32 g.
So the answer (c) is correct.

Question 10.
1 mole of any substance contains molecules.
(a) 6.023 × 10²³
(b) 6.023 × 10^-23
(c) 3.0115 × 10²³
(d) 12.046 × 10²³
Answer:
(a) 6.023 × 10²³

II. Fill in the blanks:

1. Atoms of different elements having ……… mass number, but ………. atomic numbers are called isobars.
2. Atoms of different elements having same number of ………. are called isotones.
3. Atoms of one element can be transmuted into atoms of other element by ………….
4. The sum of the numbers of protons and neutrons of an atom is called its …………
5. Relative atomic mass is otherwise known as …………
6. The average atomic mass of hydrogen is ……….. amu.
7. If a molecule is made of similar kind of atoms, then it is called ……….. atomic molecule.
8. The number of atoms present in a molecule is called its ………….
9. One mole of any gas occupies ………… ml at S.T.P
10. Atomicity of phosphorous is …………
Answer:
1. same, different
2. neutrons
3. artificial transmutation
4. mass number
5. standard atomic weight
6. 1.008
7. homo
8. atomicity
9. 22, 400
10. four

III. Match the following:

Answer:
A. (ii)
B. (iii)
C. (v)
D. (i)
E. (iv)

IV. True or False: (If false give the correct statement)

1. Two elements sometimes can form more than one compound.
2. Nobel gases are diatomic.
3. The gram atomic mass of an element has no unit.
4. 1 mole of Gold and Silver contain same number of atoms.
5. Molar mass of CO₂ is 42 g.

Answer:

1. True
2. False – Noble gases are Monoatomic.
3. False – The unit of gram atomic mass of an element is gram.
4. True
5. False – Molar mass of CO₂ is 44 g.

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: Atomic mass of aluminium is 27
Reason: An atom of aluminium is 27 times heavier than 1/12 th of the mass of the C-12 atom.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: The Relative Molecular Mass of Chlorine is 35.5 a.m.u.
Reason: The natural abundance of Chlorine isotopes are not equal.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(c) Assertion is wrong, Reason is correct.

VI. Short answer questions:

Question 1.
Define: Relative atomic mass.
Answer:
Relative atomic mass of an element is the ratio between the average mass of its isotopes to \(\frac{1}{12^{th}}\)part of the mass of a carbon-12 atom. It is denoted as A_r.
[OR]

Question 2.
Write the different types of isotopes of oxygen and its percentage abundance.
Answer:
Oxygen has three stable isotopes. They are

Question 3.
Define Atomicity.
Answer:
The number of atoms present in the molecule is called its ‘Atomicity’.

Question 4.
Give any two examples for heteroatomic molecules.
Answer:
HI, HCl, CO, HBr, HF.

Question 5.
What is Molar volume of a gas?
Answer:
One mole of any gas occupies 22.4 litres.
(or)
22400 ml at S.T.R This volume is called as molar volume.

Question 6.
Find the percentage of nitrogen in ammonia.
Answer:
Molar mass of NH₃ = 1(14) + 3(1) = 17 g

VII. Long answer questions:

Question 1.
Calculate the number of water molecule present in one drop of water which weighs 0.18 g.
Answer:
The molecular mass of water (H₂O) is 18.
18 g of water molecule = 1 mole.
0. 18 g of water = \(\frac{1}{18} \times 0.18\) = 0.01 mole.
1 mole of water (Avogadro’s number) contains 6.023 × 10²³ water molecules.
0. 01 mole of water contain \(\frac{6.023 \times 10^{23}}{1} \times 0.01\) = 6.023 × 10²¹ molecules.

Question 2.
N₂ + 3 H₂ → 2 NH₃
(The atomic mass of nitrogen is 14, and that of hydrogen is 1)
1 mole of nitrogen (……..g) +
3 moles of hydrogen (………g) →
2 moles of ammonia (………g)
Answer:
1 mole of nitrogen (28 g) +
3 moles of hydrogen (6 g) →
2 moles of ammonia (34 g)

Question 3.
Calculate the number of moles in
(i) 27 g of Al;
(ii) 1.51 × 10²³ molecules of NH₄Cl.
Answer:
(i) 27 g of Al
Given mass atomic mass = \(\frac{Given Mass}{Atomic Mass}\) = \(\frac{27}{27}\)
= 1 mole

(ii) 1.51 x 10²³ molecules of NH₄Cl
Number of moles

Question 4.
Give the salient features of “Modern atomic theory”.
Answer:
The salient features of “Modem atomic theory” are,

1. An atom is no longer indivisible.
2. Atoms of the same element may have different atomic mass.
3. Atoms of different elements may have the same atomic masses.
4. Atoms of one element can be transmuted into atoms of other elements. In other words, an atom is no longer indestructible.
5. Atoms may not always combine in a simple whole-number ratio.
6. Atom is the smallest particle that takes part in a chemical reaction.
7. The mass of an atom can be converted into energy [E = mc²].

Question 5.
Derive the relationship between Relative molecular mass and Vapour density.
Answer:
Relative molecular mass : The relative molecular mass of a gas or vapour is the ratio between the mass of one molecule of the gas or vapour to mass of one atom of hydrogen.
Vapour density : Vapour density is the ratio of the mass of certain volume of a gas or vapour, to the mass of an equal volume of hydrogen, measured under the same conditions of temperature and pressure.

According to Avogadro’s law equal volumes of all gases contain equal number of molecules.
Let the number of molecules in one volume = n, then

When cancelling ‘n’ which is common at STP, we get

Since hydrogen is diatomic,

2 × Vapour density = Relative Molecular mass of a gas
[OR]
Relative Molecular Mass = 2 × Vapour density

VIII. HOT Question:

Question 1.
Calcium carbonate is decomposed on heating in the following reaction
CaCO₃ → CaO + CO₂

1. How many moles of Calcium carbonate is involved in this reaction?
2. Calculate the gram molecular mass of calcium carbonate involved in this reaction.
3. How many moles of CO₂ are there in this equation?

Answer:
CaCO₃ → CaO + CO₂

1. 1 mole of CaCO₃ is involved in this reaction.
2. Gram molecular mass of calcium carbonate
   CaCO₃ = (40 + 12 + 3 × 16) = 52 + 48 = 100 g
3. 1 mole of CO₂ is in this equation.

IX. Solve the following problems:

Question 1.
How many grams are there in the following?
(i) 2 moles of a hydrogen molecule, H₂
(ii) 3 moles of chlorine molecule, Cl₂
(iii) 5 moles of sulphur molecule, S₈
(iv) 4 moles of a phosphorous molecule, P₄
Solution:
(i) 2 moles of a hydrogen molecule, H₂
Mass of 1 mole of hydrogen molecule = 2 g
Mass of 2 moles of hydrogen molecule = 2 × 2 = 4 g.

(ii) 3 moles of chlorine molecule, Cl₂
Mass of 1 mole of chlorine molecule = 71 g
Mass of 3 moles of chlorine molecules = 71 × 3 = 213 g.

(iii) 5 moles of sulphur molecule, S₈
Mass of 1 mole of sulphur molecule = 32 g
Mass of 5 moles of sulphur molecules = 32 × 5 = 160 g.

(iv) 4 moles of the phosphorous molecule, P₄
Mass of 1 mole of phosphorous molecule = 30.97 g
Mass of 4 moles of phosphorous molecules = 30.97 × 4 = 123.88 g.

Question 2.
Calculate the % of each element in calcium carbonate. (Atomic mass: C – 12, O – 16, Ca – 40)
Answer:
Formula to find % of each element

Question 3.
Calculate the % of oxygen in Al₂(SO₄)₃.
(Atomic mass: Al – 27, O – 16, S – 32)
Answer:
Formula:

Molar mass of Al₂(SO₄)₃ = [2(Atomic mass of Al) + 3(Atomic mass of S) + 12(Atomic mass of O)]
= 2(27) + 3(32) + 12(16) = 342 g
% of Oxygen = \(\frac{12(16)}{342}\) × 100 = 56.14%.

Question 4.
Calculate the % relative abundance of B – 10 and B – 11, if its average atomic mass is 10.804 amu.
Answer:
% of relative abundance can be calculated by the formula.
Average atomic mass of the element
= Atomic mass of 1st isotope × abundance of 1st isotope + Atomic mass of 2nd isotope × abundance of 2nd isotope
∴ Average atomic mass of Boron
= Atomic mass of B – 0 × abundance of B -10 + Atomic mass of B – 11 × abundance of B – 11
Let the abundance of B – 10 be ‘x’ and B – 11 be (1 – x)
So, 10.804 = 10 × x + 11 (1 – x)
10.804 = 10x + 11 – 11x
x = 11 – 10.804
x = 0.196
1 -x = 1 – 0.196 = 0.804
Therefore % abundance of B – 10 is 19.6% and B – 11 is 80.4%
[OR]
Let the % of the isotope B – 10 = x
Then the % of the isotope B – 11 = 100 – x

1100 – x = 1080.4
x = 19.6
% abundance of B – 10 = 19.6%
% abundance of B – 11 = 80.4%

Samacheer Kalvi 10th Science Atoms and Molecules Additional Important Questions and Answers

I. Choose the correct answer.

Question 1.
The first scientific theory of an atom was proposed by:
(a) Ruther Ford
(b) Newland
(c) John Dalton
(d) Neils Bohr
Answer:
(c) John Dalton

Question 2.
Identify the pair that indicates isobars among the following _____.
(a) \(_{1} \mathrm{H}^{2},_{1} \mathrm{H}^{3}\)
(b) \(_{17} \mathrm{Cl}^{35},_{17} \mathrm{Cl}^{37}\)
(c) \(\text { (c) }_{18} \mathrm{Ar}^{40},_{18} \mathrm{Ca}^{40}\)
(d) \(_{6} \mathrm{C}^{13},_{7} \mathrm{N}^{14}\).
Answer:
(c) \(\text { (c) }_{18} \mathrm{Ar}^{40},_{18} \mathrm{Ca}^{40}\)

Question 3.
Which one of the following represents 180 g of water?
(a) 5 moles of water
(b) 90 moles of water
(c) 6.023 × 10²⁴ molecules of water
(d) 6.023 × 10²² molecules of water
Answer:
(c) 6.023 × 10²⁴ molecules of water

Question 4.
The isotope of Carbon-12 contains _____.
(a) 6 protons and 7 electrons
(b) 6 protons and 6 neutrons
(c) 12 protons and no neutrons
(d) 12 neutrons and no protons.
Answer:
(b) 6 protons and 6 neutrons

Question 5.
Which contains the greatest number of moles of oxygen atoms?
(a) 1 mol of water
(b) 1 mole of NaOH
(c) 1 mole of Na₂CO₃
(d) 1 mole of CO
Answer:
(c) 1 mole of Na₂CO₃

Question 6.
The mass of proton or neutron is approximately _____.
(a) 1 amu
(b) 1.609 × 10^-19 g
(c) 1 g
(d) 6.023 × 10^-23 g.
Answer:
(a) 1 amu

Question 7.
The natural abundance of C-12 and C-13 are 98.90% and 1.10% respectively. The average atomic mass of carbon is:
(a) 12 amu
(b) 12.011 amu
(c) 14 amu
(d) 12.90 amu
Answer:
(b) 12.011 amu

Question 8.
The relative atomic mass of magnesium-based on C – 12 scale is _____.
(a) 24 g
(b) 24
(c) 24 amu
(d) 24 kg
Answer:
(b) 24

Question 9.
If 1.5 moles of oxygen combine with Al to form Al₂O₃, the mass of Al in g (atomic mass of Al = 27) used in the reaction is:
(a) 2.7
(b) 54
(c) 40.5
(d) 81
Answer:
(b) 54

Question 10.
The atomicity of methane is:
(a) 5
(b) 4
(c) 3
(d) 6
Answer:
(a) 5

Question 11.
Find the odd one out _____.
(a) \(_{8} \mathrm{O}^{16}\)
(b) \(_{8} \mathrm{O}^{17}\)
(c) \(_{6} \mathrm{O}^{12}\)
(d) \(_{8} \mathrm{O}^{18}\).
Answer:
(c) \(_{6} \mathrm{O}^{12}\)

Question 12.
The volume occupied by 3 moles of HCl gas at STP is:
(a) 22.4 L
(b) 44.8 L
(c) 2.24 L
(d) 67.2 L
Answer:
(d) 67.2 L

Question 13.
The mass percentage of hydrogen in ethane (C₂H₆) is:
(a) 25%
(b) 75%
(c) 80%
(d) 20%
Answer:
(d) 20%

Question 14.
Which one of the following is a homo diatomic molecule?
(a) H₂
(6) CO
(c) NO
(d) O₃.
Answer:
(a) H₂

Question 15.
The percentage of nitrogen in urea is about:
(a) 38.4
(b) 46.6
(c) 59.1
(d) 61.3
Answer:
(b) 46.6

Question 16.
Out of the following the largest number of atoms are contained in:
(a) 11 g of CO₂
(b) 4 g of H₂
(C) 5 g of NH₃
(d) 8 g of SO₂
Answer:
(b) 4 g of H₂

Question 17.
Which of the following is an example of a homo triatomic molecule?
(a) Phosphorous
(b) Sulphur
(c) Bromine
(d) Ozone.
Answer:
(d) Ozone.

Question 18.
For the reaction A + 2B → C, 5 moles of A and 8 moles of B will produce:
(a) 5 moles of C
(b) 4 moles of C
(c) 8 moles of C
(d) 13 moles of C
Answer:
(b) 4 moles of C

Question 19.
The vapour density of a gas is 32. Its relative molecular mass will be:
(a) 32
(b) 16
(c) 64
(d) 96
Answer:
(c) 64

Question 20.
Find the odd one out _____.
(a) Silver
(b) Potassium
(c) Iron
(d) Phosphorous.
Answer:
(d) Phosphorous.

II. Fill in the blanks.

1. The volume occupied by 16 g of oxygen is ………..
2. One mole of a triatomic gas contains ………… atoms.
3. Equal volume of all gases under the same conditions of temperature and pressure contain equal number of …………
4. The mass of an atom can be converted into energy by using the formula …………
5. The percentage composition is useful to determine the ………… formula and ………… formula.

Answer:

1. 11.2 L
2. 3 × 6.023 × 10²³
3. molecules
4. E = me²
5. empirical, molecular

III. Match the following:

Question 1.
Match the Column I with Column II.

Answer:
A. (ii)
B. (iii)
C. (i)
D. (v)
E. (iv)

Question 2.
Match the Column I with Column II.

Answer:
A. (iii)
B. (i)
C. (iv)
D. (v)
E. (ii)

Question 3.
Match the Column I with Column II.

Answer:
A. (iv)
B. (v)
C. (ii)
D. (iii)
E. (i)

Question 4.
Match the Column I with Column II.

Answer:
A. (v)
B. (iii)
C. (iv)
D. (i)
E. (ii)

IV. True or False: (If false give the correct statement)

1. Atoms always combine in a simple whole number ratio.
2. 2 × RMM = VD
3. The average atomic mass of Beryllium is 9.012 because of the presence of isotopes.
4. The noble gases are diatomic.
5. The number of atoms present in one mole of phosphorus(P₄) is 4 × 6.023 × 10²³

Answer:

1. False -Atoms may not combine always in a simple whole number ratio.
2. False – 2 × VD = RMM
3. True
4. False – The noble gases are mono atomic.
5. True

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: The standard unit for expressing mass of atom is amu.
Reason: Atomic mass unit is one-twelth of the mass of a C-12 atom
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: The volume occupied by 44 g of CO₂ is 22.4 L
Reason: The volume occupied by one mole of any gas is 22.4 L
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

VI. Short answer questions:

Question 1.
Define vapour density.
Answer:
Vapour density is the ratio of the mass of certain volume of a gas or vapour, to the mass of an equal volume of hydrogen measured under the same condition of temperature and pressure.
[OR]

Question 2.
What are isobars? Give an example.
Answer:
Atoms of different elements that have same atomic masses but different atomic numbers are called isobars.
e.g., \(_{18} \mathrm{Ar}^{40}\), \(_{20} \mathrm{Ca}^{40}\).

Question 3.
Write the differences between an atom and a molecule.
Answer:

Question 4.
What is artificial transmutation?
Answer:
Atoms of one element can be transmuted into atoms of other elements. In other words, the atom is no longer indestructible. It is known as artificial transmutation.

Question 5.
Classify the following based on atomicity.
Answer:
(i) Bromine
2 – Diatomic

(ii) Argon
1 – Monoatomic

(iii) Ozone
3 – Triatomic

(iv) Sulphur
8 – Polyatomic

Question 6.
Define atomic mass unit.
Answer:
Atomic mass unit is one-twelfth of the mass of carbon – 12 atom, as an isotope of carbon which contains 6 protons and 6 neutrons. It is amu.

VII. Long answer questions:

Question 1.
Explain how Avogadro hypothesis is used to derive the value of atomicity.
Answer:
(i) The Avogadro’s law states that “equal volumes of all gases under similar conditions of temperature and pressure contain the equal number of molecules”.

(ii) Let us consider the reaction between hydrogen and chlorine to form hydrogen chloride gas.
H_{2 (g)} + Cl_{2 (g)} → 2HCl _(g)
⇒ 1 volume + 1 volume → 2 volumes.

(iii) According to Avogadro’s law, 1 volume of any gas is occupied by “n” number of molecules,
“n” molecules + “n” molecules → “2n” molecules
If “n” = 1, then
1 molecule + 1 molecule → 2 molecules.
\(\frac { 1 }{ 2 }\) molecule + \(\frac { 1 }{ 2 }\) molecule → 1 molecule.

(iv) 1 molecule of hydrogen chloride gas is made up of \(\frac { 1 }{ 2 }\) molecule of hydrogen and \(\frac { 1 }{ 2 }\) molecule of chlorine.

(v) \(\frac { 1 }{ 2 }\) molecule of hydrogen contains 1 atom.
So, 1 molecule of hydrogen contains 2 atoms.
So, hydrogen atomicity is 2. Similarly, chlorine atomicity is also 2.
So, H₂ and Cl₂ are diatomic molecules.

Question 2.
Write a note on the following,
(i) Isotopeos
(ii) Isobars
(iii) Relative atomic mass.
Answer:
(i) Isotopes : Atoms of same element with different mass number. Eg: ₁₇Cl³⁵, ₁₇Cl³⁷.
(ii) Isobars : Atoms of different elements with same mass number. Eg: ₁₈Ar⁴⁰, ₂₀Ca⁴⁰
(iii) Relative Atomic Mass (RAM) :

Question 3.
Sodim bicarbonate breaks down on heating as follows:
2NaHCO₃ → Na₂CO₃ + H₂O + CO₂
(Atomic mass of Na = 23, H = 1, C = 12, O = 16)
(i) How many moles of NaHCO₃ are there in the equation?
Answer:
2 moles.

(ii) What is the mass of CO₂ produced in the equation?
Answer:
44 g

(iii) How many moles of water molecules are produced in the equation?
Answer:
1 mole.

(iv) What is the mass of NaHCO₃ used in this equation?
Answer:
= 2[23 + 1 + 12 + 3(16)]
= 2[84]
= 168 g

(v) What is the volume occupied by CO₂ in this equation?
Answer:
22.4 lit.

VIII. Hot Questions

Question 1.
Why do we take an atomic mass of Carbon – 12 as standard?
Answer:
Carbon – 12 is the standard while measuring the atomic masses. Because no other nuclides other than C – 12 have exactly whole-number masses in this scale. This is due to the different mass of neutrons and protons acting to change the total mass in nuclides with proton/neutron ratio other than 1 : 1 ratio of carbon – 12.

Question 2.
The cost of common salt (NaCl) is Rs 18 per kg. Calculate the cost of the salt per mole.
Answer:
Gram molar mass of NaCl = 23 + 35.5
= 58.5 g
1000 g of NaCl costs = Rs 18
∴ 58.5 g of NaCl costs = \(\frac{18}{1000}\) × 58.5
= Rs 1.053
The cost of one mole of NaCl = Rs 1.053

Question 3.
What will be the mass of one \(^{12} \mathbf{C}\) atom in g?
Answer:
1 mol of \(^{12} \mathbf{C}\) atoms = 6.022 × 10²³ atoms = 12 g
Thus, 6.022 × 10²³ atoms of \(^{12} \mathbf{C}\) have mass = 12 g
∴ 1 atom of \(^{12} \mathbf{C}\) will have mass = \(\frac{12}{6.022 \times 10^{23}}\) g = 1.9927 × 10^-23 g.

IX. Solve the following problems:

Question 1.
Calculate the average atomic mass of carbon, if the natural abundance of C – 12 and C – 13 are 98.90% and 1.10% respectively.
Solution:
Average atomic mass of carbon
\(=\left(12 \times \frac{98.9}{100}\right)+\left(13 \times \frac{1.1}{100}\right)\)
= (12 × 0.989) +(13 × 0.011)
= 11.868 + 0.143
= 12.011 amu.

Question 2.
Find how many moles are there in
(a) 98 g of H₂SO₄
Answer:
(a) 98 g of H₂SO₄
GMM of H₂SO₄ = 2(1) + 32 + 4(16)
= 98 g
Number of moles = \(\frac{Given Mass}{Mol. Mass}\)
= \(\frac{98}{98}\)
= 1 mole

(b) 18.069 × 10²³ atoms of calcium
Answer:
Number of moles

= 3 moles

(c) 4.48 L of CO₂
Answer:
Number of moles

Question 3.
Calculate the number of moles in
(i) 12.046 × 10²³ atoms of copper
(ii) 27.95 g of iron
(iii) 1.51 × 10²³ molecules of CO₂
Answer:
(i) 12.046 × 10²³ atoms of copper
6.023 × 10²³ atoms of copper = 1 mole
12.046 × 10²³ atoms of copper = \(\frac{1 \times 12.046 \times 10^{23}}{6.023 \times 10^{23}}\) = 2 moles of copper

(ii) 27.95 g of iron
55.9 g of iron = 1 mole
27.95 g of iron = \(\frac{1}{55.9}\) × 27.95 = 0.5 mole of iron.

(iii) 1.51 × 10²³ molecules of CO₂
No of moles = \(\frac{\text { No. of molecules }}{\text { Avogadro number }}\)
= \(\frac{1.51 \times 10^{23}}{6.023 \times 10^{23}}\)
= 0.25 mole of CO₂

Question 4.
Calculate the number of atoms of mercury present in 1 kg of Mercury. [Atomic mass of Hg = 200.6]
Answer:
200.6 g of Hg contains 6.023 × 10²³ Hg atoms
∴ 1 Kg of Hg will contain = \(\frac{6.023×10^{23}}{200.6}\) × 1000
= 30.02 × 10²³ Hg atoms

Question 5.
How many molecules are present in 7 × 10^-3 m³ of NH₃ at STP?
Answer:
Molar volume = 22.4 dm³ = 2.24 × 10^-2 m³
2.24 × 10^-2 m³ of NH₃ at STP contains 6.023 × 10²³ NH₃ molecules.
:. 7 × 10^-3 m³ of NH₃ will contain
= \(\frac{6.023×10^{23}}{2.24×10^{-2}}\) × 7 × 10^-3
18.82 × 10²² NH₃ molecule

Question 6.
What is the mass in grams of the following?
(a) 3 moles of NaOH
(b) 6.023 × 10²² atoms of Ca
(c) 224 L of CO₂
Answer:
Formula:

(a) 3 moles of NaOH
Mass of 3 moles of NaOH = 3 × mol. mass of NaOH
GMM of NaOH = 23 + 16 + 1 = 40 g
Mass of 3 moles of NaOH = 3 × 40 = 120 g

(b) 6.023 × 10²² atoms of Ca = n × atomic mass of ca

= 4 g

(c) 224 L of CO₂
Mass of 224 L of CO₂

= 10 × 44
= 440 g

Question 7.
How many grams are therein:
(i) 5 moles of water
(ii) 2 moles of Ammonia
(iii) 2 moles of Glucose
Solution:
(i) 5 moles of water.
Mass of 1 mole of water (H₂O) = 18 g (2 + 16)
Mass of 5 moles of H₂O = 18 × 5 = 90 g.

(ii) 2 moles of ammonia.
Mass of 1 mole of ammonia (NH₃) = 17 g (14 + 3)
Mass of 2 moles of ammonia = 17 × 2 = 34 g.

(iii) 2 moles of glucose.
Mass of 1 mole of glucose (C₆H₁₂O₆) = 180 g (72 + 12 + 96)
Mass of 2 moles of glucose = 180 × 2 = 360 g.

Question 8.
Calculate tbe molar mass of the following compounds.
(a) Urea (NH₂CONH₂)
(b) Ethanol(C₂H₅OH);
(c) Boric acid (H₃BO₃)
[Atomic mass of N – 14, H – 1, C – 12, B – 11, O – 16]
Answer:
(a) Urea (NH₂CONH₂) = 2(14) + 4(1) + 1(16) + 1(12)
= 28 + 4 + 16 + 12
= 60 g

(b) Ethanol(C₂H₅OH) = 2(12) + 6(1) + 1(16)
= 24 + 6 + 16 = 46 g

(c) Boric acid (H₂BO₃) = 3(1) + 1(11) + 3(16)
= 3 + 11 + 48
= 62 g

Question 9.
Mass of one atom of an element is 6.645 × 10^-23 g. How many moles of element are there in 0.320 kg.
Answer:
Mass of one atom of an element = 6.645 × 10^-23 g
∴ Mass of 1 mol of atom = 6.645 × 10^-23 × 6.023 × 10²³ = 40 g
Number of moles =

Students can download 10th Social Science Geography Chapter 2 Climate and Natural Vegetation of India Questions and Answers, Notes, Samacheer Kalvi 10th Social Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Social Science Solutions Geography Chapter 2 Climate and Natural Vegetation of India

Samacheer Kalvi 10th Social Science Climate and Natural Vegetation of India Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
Meteorology is the science of:
(a) Weather
(b) Social
(c) Political
(d) Human
Answer:
(a) Weather

Question 2.
We wear cotton during ……….
(a) Summer
(b) Winter
(c) Rainy
(d) Northeast monsoon
Answer:
(a) Summer

Question 3.
Western disturbances cause rainfall in:
(a) Tamilnadu
(b) Kerala
(c) Punjab
(d) Madhya Pradesh
Answer:
(c) Punjab

Question 4.
………. helps in quick ripening of mangoes along the coast of Kerala and Karnataka.
(a) Loo
(b) Norwester
(c) Mango showers
(d) Jet stream
Answer:
(c) Mango showers

Question 5.
……………. is a line joining the places of equal rainfall.
(a) Isohyets
(b) Isobar
(c) Isotherm
(d) Latitudes
Answer:
(a) Isohyets

Question 6.
The climate of India is labelled as ………
(a) Tropical humid
(b) Equatorial Climate
(c) Tropical Monsoon Climate
(d) Temperate Climate
Answer:
(c) Tropical Monsoon Climate

Question 7.
The monsoon forests are otherwise called as
(a) Tropical evergreen forest
(b) Deciduous forest
(c) Mangrove forest
(d) Mountain forest
Answer:
(b) Deciduous forest

Question 8.
……. forests are found above 2400 m Himalayas.
(a) Deciduous forests
(b) Alpine forests
(c) Mangrove forests
(d) Tidal forests
Answer:
(b) Alpine forests

Question 9.
Sesahachalam hills, a Biosphere reserve is situated in
(a) Tamil Nadu
(b) Andhra Pradesh
(c) Madhya Pradesh
(d) Karnataka
Answer:
(b) Andhra Pradesh

Question 10.
………… is a part of the world network biosphere reserves of UNESCO .
(a) Nilgiri
(b) Agasthiyamalai
(c) Great Nicobar
(d) Kachch
Answer:
(a) Nilgiri

II. Match the following

Answer:
A. (iv)
B. (v)
C. (ii)
D. (i)
E. (iii)

III. Consider the given statements and choose the correct option from the given below ones.

Question 1.
Assertion(A): Monsoons are a complex meteorological phenomenon. Reason(R): Meteorologists have developed a number of concepts about the origin of monsoons.
(a) Both (A) and (R) are true: R explains A
(b) Both (A) and (R) are true: R does not explain A.
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(a) Both (A) and (R) are true: R explains A

Question 2.
Assertion(A): The Himalayas acts as a climatic barrier.
Reason(R): The Himalayas prevents cold winds from central Asia and keep the Indian Sub-continent warm.(Give option for this questions)
(a) Both (A) and (R) are true: R explains A
(b) Both (A) and (R) are true: R does not explain A.
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(a) Both (A) and (R) are true: R explains A

IV. Choose the inappropriate answer

Question 1.
Tidal forests are found in and around ……..
(a) Desert
(b) The deltas of Ganga and Brahmaputra
(c) The delta of Godavari
(d) The delta of Mahanadhi
Answer:
(a) Desert

Question 2.
Climate of India is affected by:
(a) Latitudinal extent
(b) Altitude
(c) Distance from the sea
(d) Soil
Answer:
(d) Soil

V. Answer briefly

Question 1.
Define ‘Meteorology’.
Answer:
The branch of science concerned with the processes and phenomena of the atmosphere, especially as a means of forecasting the weather.

Question 2.
What is meant by ‘normal lapse rate’?
Answer:
Temperature decreases when the altitude increases .Normal Lapse rate is a phenomenon in which temperature decreases at the rate of 6.5°C for every 1000mts of ascent. Hence places in the mountains are cooler than the places on the plain.

Question 3.
What are ‘jet streams’?
Answer:
In the upper layers of the atmosphere, there are strong westerly winds concentrated in a relatively narrow and shallow stream known as “Jet streams” They cause heavy rainfall in North-west India.

Question 4.
Write a short note on ‘Monsoon wind’.
Answer:

1. The Word ‘Monsoon’ is derived from the Arabic word “Mausim” which means season.
2. Monsoons are a complex meteorological phenomenon .
3. These winds originates due to the seasonal migration of planetary winds and pressure belts following the position of the sun.
4. During summer they blow from South west to North east ( South West monsoon) June-September and from the North east to South west (North East monsoon) October and November.

Question 5.
Name the four distinct seasons of India.
Answer:

1. Winter or cold weather season (Jan-Feb)
2. Pre Monsoon or Summer (March-May)
3. Southwest Monsoon or rainy season (June-September)
4. Northeast Monsoon season (October-December)

Question 6.
What is ‘burst of monsoon’?
Answer:

1. Prior to the onset of the Southwest monsoon the temperature in North India reaches up to 46°C.
2. The sudden approach of monsoon wind over South India with lightning and thunder is termed as the “break or burst of monsoon”.

Question 7.
Name the areas which receive heavy rainfall.
Answer:

1. Middle Ganga Valley
2. Western Ghats
3. Eastern Maharashtra
4. Madhya Pradesh and Odisha

Question 8.
State places of mangrove forest in India.
Answer:

1. Mangrove forests occur in and around the deltas, estuaries and creeks prone to tidal influences.
2. In India they are found in deltas of Ganga, Brahmaputra (largest), the deltas of Mahanadi, Godavari and Krishna rivers.

Question 9.
Name the trees of tropical evergreen forest.
Answer:
The most important trees are rubber, mahogany, ebony, rosewood, coconut, bamboo, cinchona, candes, palm, iron wood and cedar.

Question 10.
Write any five Biosphere Reserves in India.
Answer:

1. Biosphere Reserves are the protected areas of land coastal environments where in people are an integral component of the system.
2. The Indian Government has established 18 Biosphere Reserves. Gulf of Mannar Nilgiris, Agasthiamalai, Kanjanjunga, Great Nicobar etc.

Question 11.
What is ‘Project Tiger’?
Answer:
Project Tiger was launched in April 1973 with the aim to conserve tiger population in specifically constituted “Tiger Reserves” in India. This project is benefited tremendously, with an increase of over 60% – the 1979 consensus put the population at 3,015.

VI. Distinguish between

Question 1.
Weather and Climate.
Answer:
Weather:

1. State of the atmosphere of a place at a given point of time.
2. Weather changes occur daily.
3. Temperature, wind pressure, humidity duration of sunlight and rainfall decides the weather.

Climate:

1. Accumulation of daily and seasonal weather events of a given location over a period of time.
2. It is an average of weather condition over a period of 30-35 years.
3. Climate of a place is determined by Latitude, altitude, distance from the seas, relief features etc.

Question 2.
Tropical Evergreen Forest and Deciduous Forest.
Answer:
Tropical Evergreen forest:

1. These forests are found in the areas where the annual rainfall is 200 cm and more.
2. The tress of these forests do not shed their leaves.
3. Rubber, iron wood, Mahogony are some of the main trees.

Deciduous Forest:

1. These forests are found in the areas with 100 to 200cm annual rainfall.
2. The trees of these forests shed their leaves in spring and early summer.
3. Sandalwood, teak, sal, padak are some of the main trees.

Question 3.
North East Monsoon and South West Monsoon.
Answer:
North East Monsoon:

1. These monsoon winds blow from North-east to South west.
2. They blow during the month of October-November.
3. TamilNadu and Andhra Pradesh gets rainfall from this monsoon.

South West Monsoon:

1. These monsoon winds blow from South west towards North east.
2. They blow during the month of June-September.
3. 75% of India’s rainfall is from this monsoon winds.

VII. Give reasons for the following topics

Question 1.
Western Coastal plain is narrow.
Answer:
It lies between the Western Ghats and Arabian Sea.
It is a narrow plain, which stretches from Gujarat to Kerala with an average width of 50 – 80 km. It is mainly characterised by sandy beaches, coastal sand, dunes, mud flats, lagoons, estuary, laterite platforms and residual hills.

Question 2.
India has a tropical monsoon climate.
Answer:
Latitudinally India lies between 8°4′ N and 37°6’N latitudes. Tropic of Cancer (23° 30’N) divides the country into two equal halves . Most parts of the country’ lie in the Tropical Zone and receives rainfall from monsoon winds which is the dominating climatic factor. Hence India has Tropical monsoon climate.

Question 3.
Mountains are cooler than the plains.
Answer:
When the altitude increases, the temperature decreases. Temperature decreases at the rate of 6.5°C for every 1000 metres of ascent. Hence, places in the mountains are cooler than the places on the plains. That is why the places located at higher altitudes even in South India have cool climate. Ooty and several other hill stations of South India and of the Himalayan ranges like Mussoorie, Shimla, etc., are much cooler than the places located on the Great Plains.

VIII. Write in detail

Question 1.
Write about South West Monsoon.
Answer:

1. Southwest monsoon season is also known as the rainy season in India.
2. The onset of Southwest monsoon season takes place over the southern tip of the country’ by the first week of June, advances along the Konkon coast in early June and covers the whole country by 15th July.
3. Jet stream and ELNino are the two factors that determine the occurrence of Southwest monsoon.
4. Due to the high temperature over north India creates a low-pressure trough which draws the moisture-laden winds from the Indian Ocean towards the Indian landmass.
5. The sudden approach of monsoon wind over south India with ‘ lightning and the thunder indicates the onset of south-west monsoon.
   This is also known as “break or burst of monsoon”.
6. The monsoon winds strike against the southern tip of the Indian landmass and get divided into two branches.
   • (a) Arabian sea branch (of Southwest monsoon)
   • (b) The Bay of Bengal branch (of Southwest monsoon)

(a) Arabian sea branch of South west monsoon:

• The Arabian sea branch of south west monsoon gives heavy rainfall to the west coast of India as it is located in the wind wards side of the Western Ghats.
• The other part which advances towards north strikes against the Himalayan mountains results in heavy rainfall in north.

As Aravalli mountains lie parallel to the wind direction. Rajasthan and the western parts do not get much rainfall.

(b) Bay of Bengal branch of south west monsoon:

• The Wind from Bay of Bengal moves towards north east India and Myanmar.
• This wind is trapped by Garo, Khasi and Jaintia hills and gives the heaviest rainfall to Meghalaya (at Mawsynram).
• This wind gets deflected towards west.
• When the wind moves from east to west rainfall decreases as it looses its moisture.
• Tamil Nadu receives only a meager rainfall as the state is located on the leeward side.

About 75% of India’s rainfall is from the south west monsoon.

Question 2.
Describe the forests of India.
Answer:
Natural Vegetation refers to a plant community which has grown naturally without human aid
and has been left undisturbed by human for a long time.

Tropical Evergreen Forest:
These forests are found in areas with 200 cm or more annual rainfall.The annual temperature is about more than 22°C and the average annual humidity exceeds 70 percent in this region. Western Ghats in Maharashtra, Karnataka, Kerala, Andaman-Nicobar Islands, Assam, West Bengal, Nagaland, Tripura, Mizoram, Manipur and Meghalaya states have this type of forests. The most important trees are rubber, mahogany, ebony, rosewood, coconut, bamboo, cinchona, candes, palm, iron wood and cedar.

Tropical Deciduous Forest:
It covers a large area of the Peninsula and northern India, where the rainfall is from 100 to 200 m. These trees of the forests shed their leaves for a few weeks in early summer. The main trees are teak, Sandalwood, deodars, sisam, sal and redwood.

Tropical Dry Forest:
These are found in the areas with 50 to 100 cm. annual rainfall.They represent a transitional type of forests. These are found in east Rajasthan, Haryana, Punjab, Western Uttar Pradesh, Madhya Pradesh, Eastern Maharashtra, Telangana, West Karnataka and East Tamilnadu. The important species are mahua, banyan, amaltas, palas, haldu, kikar, bamboo, babool, khair etc.,

Mountain or Montane Forest:
These forests are classified on the basis of altitude and amount of rainfall. Accordingly two different types of forests namely Eastern Himalayas Forests and Western Himalayas Forests. Eastern Himalayan Forest: These are found on the slopes of the mountains in north-east states. They receive rainfall of more than 200 cm. The vegetation is of evergreen type. Sal, oak, laurel, amura, chestnut, cinnamon are the main trees from 1200 to 2400 m altitude oak, birch, silver, fir, fine, spruce and juniper are the major trees from 2400 to 3600 m height. Western Himalayan Forest: The rainfall of this region is moderate. They are found n the states of Jammu and Kashmir, Himachal Pradesh and Uttarakhand. In altitude from 900 to 1800 m, chir tree is the most common tree. The other important trees of this region are sal, semal, dhak, jamun and jujube.

Alpine Forest:
It occurs all along the Himalayas with above 2400 m altitude. These are purely having coniferous trees. Oak, silver fir, pine and juniper are the main trees of these forests. The eastern parts of Himalayas has large extent of these forests.

Tidel Forest:
These forests occur in and around the deltas, estuaries and creeks prone to tidal influences and as such are also known as delta or swamp forests. The delta of the Ganga-Brahmaputra has the largest tidal forest. The deltas of Mahanadi, Godavari and Krishna rivers are also known for tidal forests. These are also known as mangrove forest.

Coastal Forest:
These are littoral forests. Generally, coastal areas have these types of forests. Casurina, palm and coconut are the dominant trees. Both the eastern and western coasts have this type of forests.

Riverine Forest:
These forests are found along the rivers on Khadar areas. These are known for tamarisk and tamarind trees. The rivers of Great Plains are more prominent for this type of natural vegetation.

Question 3.
Write the names of biosphere reserves and their location in India.
Answer:
The Indian Government has established 18 Biosphere Reserves which protect larger areas of natural habitat and often include one or more national parks along with the buffer zones that are open to some economic uses.

Biosphere Reserves	State
Achanakmar-Amarkantak	Madhya Pradesh, Chhattisgarh
Agasthyamalai	Kerala
Dibru Saikhowa	Assam
Dihang Dibang	Arunachal Pradesh
Great Nicobar	Andaman and Nicobar Islands
Gulf of Mannar	Tamil Nadu
Kachch	Gujarat
Kanchenjunga	Sikkim
Manas	Assam
Nanda Devi	Uttarakhand
The Nilgiris	Tamil Nadu
Nokrek	Meghalaya
Pachmarhi	Madhya Pradesh
Simlipal	Odisha
Sundarbans	West Bengal
Cold desert	Himachal Pradesh
Sesahachalam hills	Andhra Pradesh
Panna	Madhya Pradesh

IX. Map

Mark the following on the outline map of India.

Question 1.
Direction of South West Monsoon wind.
Answer:

Question 2.
Direction of North East Monsoon wind.
Answer:

Question 3.
Areas of heavy rainfall.
Answer:

Question 4.
Mountain forests.
Answer:

Question 5.
Panna biosphere reserve
Answer:

Question 6.
Agasthiyamalai biosphere reserve
Answer:

TB. PNo: 99
Find Out

Question 1.
Find out the temperature of Ooty (2240m). If it is 35°C in Chennai (6.7 m).
Answer:
For every 1000 mt altitude temperature decreases by 6.5°C . So the temperature of Ooty is nearly 15°C.

TB. PNo: 102
HOTS

Question 1.
Why is Mawsynram, the wettest place in the world?
Answer:
Mawsynram in Meghalaya receives the highest rainfall (1141 cm) in the world. Almost daily it rains. Thus make this place a swampy and the wettest due to very dense vegetation.

Samacheer Kalvi 10th Social Science Climate and Natural Vegetation of India Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
The most dominant factor which affects the climate of India is:
(a) Relief
(b) Monsoon winds
(c) Temperature
(d) Soil
Answer:
(b) Monsoon winds

Question 2.
The Local storms in the north eastern part of India during the weather seasons are called
(a) Loo
(b) Norwesters
(c) Mangoshowers
Answer:
(a) Loo

Question 3.
Seventy-five percentage of Indian rainfall is from this wind:
(a) Western Disturbance
(b) North East monsoon
(c) Norwesters
(d) South West monsoon
Answer:
(d) South West monsoon

Question 4.
The mountain which stands parallel to the direction of the south-west monsoon wind ….
(a) Vindhya
(b) Aravalli
(c) Satpura
Answer:
(b) Aravalli

Question 5.
The ……………. forests are found in the region where the rainfall is 200 cm and above.
(a) Tropical evergreen
(b) Tidal
(c) Tropical deciduous
(d) Alpine
Answer:
(a) Tropical evergreen

Question 6.
……… experience continental climate.
(a) Chennai
(b) Mumbai
(c) Delhi
Answer:
(c) Delhi

Question 7.
The term ……………. includes animals of any habitat in nature.
(a) Mammals
(b) Forests
(c) Insects
(d) Wild life
Answer:
(d) Wild life

Question 8.
In India, 85% of the rain is received from the ……….
(a) North-east
(b) South-west
(c) South-east
Answer:
(b) South-west

Question 9.
In the year ……………. United nations Convention on Biological Diversity (CBD) recognizes the sovereign rights of the states to use their own Biological Resources.
(a) 1992
(b) 1982
(c) 1979
(d) 1929
Answer:
(a) 1992

Question 10.
The ……… prevents the cold polar winds blowing from Central Asia.
(a) Aravalli Hills
(b) Bay of Bengal
(c) Himalayas
Answer:
(c) Himalayas

Question 11.
The highest rainfall region in India is located in this state:
(a) Assam
(b) Bihar
(c) Meghalaya
(d) Manipur
Answer:
(c) Meghalaya

Question 12.
There is a peculiar uniformity in the climate of India due to its unique ……..
(a) Geography
(b) Physiography
(c) Demography
Answer:
(b) Physiography

II. Match the following

Question 1.
Match the Column I with Column II.

Answer:
A. (iii)
B. (i)
C. (v)
D. (ii)
E. (iv)

Question 2.
Match the Column I with Column II.

Answer:
A. (vi)
B. (iii)
C. (v)
D. (ii)
E. (iv)
F. (i)

Question 3.
Match the Column I with Column II.

Answer:
A. (v)
B. (i)
C. (ii)
D. (vi)
E. (iv)
F. (iii)

III. Consider the given statements and choose the correct option from the given below ones

Question 1.
Assertion(A): Peninsular India enjoys equable climate.
Reason(R): The peninsular region is surrounded by the seas on three sides, not very far from the sea.
(a) Both (A) and (R) are true: R explains A
(b) Both (A) and (R) are true: R does not explain A
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(c) (A) is correct (R) is false

Question 2.
Assertion(A): Two different types-of mountain forests are in India namely Eastern Himalayan forests and Western Himalayan forests.
Reason(R): Mountain forests are classified on the basis of altitude and amount of Rainfall.
(a) Both (A) and (R) are true: R explains A
(b) Both (A) and (R) are true: R does not explain A
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(b) Both (A) and (R) are true: R does not explain A

Question 3.
Assertion(A): Systematic change in the direction of planetary winds is known as monsoons.
Reason(R): Monsoon winds originates due to the seasonal migration of planetary winds and pressure belts following the position of the Sun.
(a) Both (A) and (R) are true: R explains A
(b) Both (A) and (R) are true: R does not explain A
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(c) (A) is correct (R) is false

Question 4.
Assertion(A): Rajasthan remains as desert.
Reason(R): As Aravalli mountain is located parallel to the Arabian Sea branch South west Monsoon winds the western part (Rajasthan) do not receive much rainfall. To the Bay of Bengal Branch of South west Monsoon wind it is located on the leeward side.
(a) Both (A) and (R) are true: R explains A
(b) Both (A) and (R) are true: R does not explain A
(c) (A) is correct (R) is false
(d) (A) is false (R) is true
Answer:
(a) Both (A) and (R) are true: R explains A

IV. Choose the inappropriate answer

Question 1.
The pre-monsoon showers are known as mango showers in:
(a) Kerala and Karnataka
(b) Punjab and Haryana
(c) Hot weather season
(d) Helps quick ripening of mangoes
Answer:
(b) Punjab and Haryana

Question 2.
Tropical deciduous forests trees are of economic importance:
(a) Have valuable trees like teak, sal.
(b) To make fragnant oil, varnish, perfumes.
(c) Do not shed their leaves.
(d) Found in rainfall areas of 100 to 200 cm.
Answer:
(c) Do not shed their leaves.

Question 3.
Tidal forests are also known as swamp or delta forests.
(a) These forests are not prone to tidal waves.
(b) Known as mangrove forests.
(c) Occur in and around deltas, estuaries.
(d) Prone to tidal influences.
Answer:
(a) These forests are not prone to tidal waves.

Question 4.
Biosphere Reserves are protected areas of coastal and land environment.
(a) Indian Government has established 18 Biosphere Reserves.
(b) Do not protect areas of natural habitat.
(c) People are an integral component of the system.
(d) One or more National parks preserves along with buffer zone.
Answer:
(b) Do not protect areas of natural habitat.

V. Answer briefly

Question 1.
Name the classification of Natural vegetation.
Answer:
Natural Vegetation can be classified as:

1. Tropical Evergreen forests
2. Tropical deciduous forests
3. Tropical dry forests
4. Desert and semi-desert
5. Mountain forests
6. Alpine forests and
7. Tidal forests

Question 2.
Name the factors affecting the climate of India.
Answer:
Climate of India is affected by the factors of latitude, distance from the seas, Monsoon wind, relief features and jet stream.

Question 3.
The climate and weather conditions in India are governed by the three-atmosphere conditions. Name them.
Answer:

1. The Pressure and Surface winds.
2. Upper air Circulation
3. Western cyclonic disturbances and tropical conditions

Question 4.
What is ElNino? How does it affect the climate of India?
Answer:
ElNino is a complex global phenomena of weather that appears once eveiy five to ten years. It is a cause for the delay of onset of the southwest monsoon in India.

Question 5.
What is the Characteristic features of monsoon rains in India?
Answer:

1. The Monsoon rains are pulsating in nature
2. They can cause heavy rainfall in one part and drought in the other.
3. They are known for their uncertainties.

Question 6.
What is the role of Jet stream regarding the climate of India?
Answer:

1. The arrival and departure of monsoon winds is determined by Jet stream.
2. Cause tropical depressions both during South west monsoon and North east monsoon.
3. Plays a vital role in bringing western disturbances to India there by helping winter wheat cultivation.

Question 7.
What values are associated with the monsoon in India?
Answer:

• Monsoon acts as unifying bond for India.
• The unifying influence of the monsoon on the Indian Subcontinent is quite perceptible.
• The Seasonal alteration of the wind systems and the associated weather conditions provide a rhythmic cycle of seasons.
• The Indian landscape, its animal and plant life, its entire agricultural calender and the life of the people, including their festivities, revolve around this phenomenon.
• Year after year, people of India from North to South and from east to west, eagerly await the arrival of the monsoon. These monsoon winds binds the whole country by providing water to set the agricultural activities in motion.
• The rivers valleys which carry this water also unite as a single river valley unit.

Question 8.
Give a brief note on the Indian Board for Wild life:
Answer:

1. The Indian Board for wild life was constituted in 1952 to suggest means of protection, conservation and management of wild life to the Government of India.
2. The Government of India enacted wild life (protection) Act in 1972 with the objective of effectively protecting the wild life.

Question 9.
Explain the steps taken to conserve wildlife.
Answer:
The Wild Life Act Of India protects and conserves this grest heritage of nation. The first weak of October is observed as Wild life Week Of India.

Question 10.
Give the Full form of these abbreviations.

1. IBWL
2. CBD
3. ITCZ

Answer:

1. IBWL : Indian Board for Wild Life.
2. CBD: Convention on Biological Diversity.
3. ITCZ : Inter Tropical Convergence Zone.

Question 11.
Why does the coromandal coast face frequent cyclones?
Answer:
The north east monsoon winds by crossing the Bay of Bengal absorbs moisture and gives heavy rain to the coromandal coast. These are frequent cyclones formed in the Bay of Bengal and they cause heavy damage to life and property along the coromandal coast.

Question 12.
Give a brief description of the Mangrove forests.
Answer:

• The mangrove tidal forests are found in the areas of coasts influenced by tides. Hence, mangroves are the common varities with roots of the plants submerged under water. The deltas of the Ganga, the Mahanadi, the Krishna, the Godavari and the Kaveri are covered by such vegetation. In the Ganga-Brahmaputra delta sundari trees are found which provides durable hard timber.
• Palm, coconut, Keora agar also grow in some parts of the delta.
• Royal Bengal Tiger is the famous animal in these forests. Turtles, crocodiles, gharials and snakes are also found in these forests.

VI. Distinguish between

Question 1.
Winter/Cold weather and Summer/Hot weather season.
Solution:
Winter or Cold weather season:

1. In India,winter weather period is January-February.
2. The mean temperature increases from North to South.
3. Western Disturbances occurs in this season.
4. Generally fine weather and low tempertaure.

Summer or Hot weather season:

1. The summer season is from March- May.
2. The mean tempertaure increases from South to North.
3. Mango showers, Norwesters or Kalbaisakhi occurs in this season.
4. Generally hot and dry weather.

Question 2.
Heavy rainfall and less/low rainfall region.
Answer:
Heavy rainfall region:

1. These areas get annual rainfall of 200 cms and above.
2. Western coast, Assam, South Meghalaya are heavy rainfall areas.

Less or low rainfall region:

1. These areas get annual rainfall less than 100 cms.
2. Rajasthan, Punjab, Haryana, Western and South western parts of Uttar Pradesh, plateau region gets less rainfall.

Question 3.
Windward side and Leeward side.
Answer:
Windward side:

1. The slope of the mountain that lie on the path of rain bearing winds.
2. The windward side gets more rainfall.
3. Western slopes of Western Ghats – West coastal plains.

Leeward side:

1. The slope of the mountain that do not face the rain bearing winds.
2. The Leeward side gets less or no rainfall.
3. Eastern slopes of Western Ghats – Deccan Plateau.

Question 4.
Eastern and Western Himalayan forests.
Answer:
Eastern Himalayan forests:

1. The vegetation of this forest is’ evergreen as these forests receive more than 200cm rainfall.
2. Pine, Sal Fir, Oak, Laurel are some of the main trees of these forests.
3. These forests are found in the North Eastern states.

Western Himlayan forests:

1. The rainfall of this region is moderate and have varied vegetation regards to altitude.
2. Upto 900m altitude semi desert vegetation from 900m – 1800m chir tree and sal, at 1800m conifer trees.
3. These forests are found in the states of Jammu and Kashmir, Himachal Pradesh and UttaraKhand.

VII. Give reasons for the following topics

Question 1.
Kolkatta receives more rainfall than Bikaner in Rajasthan.
Answer:
Air near the coast has more moisture and greater potential to produce precipitation. Due to this fact Kolkatta near the coast receives more rainfall (119cm) than Bikaner (24cm) which is located in the interior part.

Question 2.
In India Conservation and management of Biodiversity is necessary why?
Answer:
Hunting, Poaching, deforestation and encroachments in the natural habitats have caused extinction of some species and many are in the danger of extinction. The role of wild life in maintaining the ecological balance made it necessary for conservation and management of Biodiversity.

Question 3.
Relief of India has a great bearing on climate.
Answer:
The elements of climate such as temperature, atmospheric pressure, direction of winds and the amount of rainfall are affected by the presence of relief features as they act as a climatic barrier like the Himalayas and Western Ghats.

VIII. Write in detail

Question 1.
What are the major determinants of climate of a place? Explain them.
Answer:
The major determinants of climate of a place are,

1. Latitude
2. Altitude
3. Distance from the seas
4. Monsoon winds
5. Relief features (Mountains)
6. Jet Streams

1. Latitude:
Latitudinally, India lies between 8°4’N and 37°6’N latitudes. The Tropic of cancer divides the country into two equal halves. The area located to the south of Tropic of cancer experiences high temperature and no severe cold season throughout the year whereas, the areas to the north of this parallel enjoys subtropical climate. Here, summer temperature may rise above 40°C and it is close to freezing point during winter.

2. Altitude:
As one goes from the surface of the earth to higher altitudes, the atmosphere becomes less dense and temperature decreases. The hills are therefore cooler during summer.

3. Distance from the seas:
Distance from the sea does not cause only temperature and pressure variations but also affects the amount of rainfall. As the distance from the sea increased its moderating influence decreases and the people experience extreme weather conditions. This condition is known as continentality.(i.e.) Very hot during summers and very cold during winter.

4. Monsoon winds:
The most dominant factor which affects the climate of India is the monsoon winds. These are seasonal reversal winds and India remains in the influence of these winds for a considerable part of a year. Though, the sun’s rays are vertical over the central part of India during the mid-June, the summer season ends in India by the end of May. It is because the onset of southwest monsoon brings down the temperature of the entire India and causes moderate to heavy rainfall in many parts of the country. Similarly, the climate of southeast India is also influenced by northeast monsoon.

5. Relief features (Mountains):
Relief of India has a great bearing on major elements of climate such as temperature, atmospheric pressure, direction of winds and the amount of rainfall. High mountains act as barriers for cold or hot winds; they may also cause precipitation if they are high enough and lie in the path of rain-bearing winds. The leeward side of mountains remains dry.

6. Jet Streams:
Jet streams are the fast moving winds blowing in a narrow zone in the upper atmosphere. According to the Jet stream theory, the onset of southwest monsoon is driven by the shift of the sub tropical westerly jet from the plains of India towards the Tibetan plateau. The easterly jet streams cause tropical depressions both during southwest monsoon and retreating monsoon.

Question 2.
Write about the factors that affect the climate of India.
Answer:
Climate of India is affected by the factors of latitude, altitude, distance from the seas, monsoon winds and jet streams.

Latitude:

1. Latitudinally India is located in the Tropical belt between 8°4’N and 37°6’N latitudes.
2. The tropic of cancer divides the country into two equal halves.
3. This enables the places south of Tropic of cancer (23°30’N) to experience high temperature and no severe cold.
4. The places north of Tropic of cancer enjoy sub tropical climate.

Altitude:

1. When the altitude increases, temperature decreases as per the phenomena. “Normal Lapse rate”. For every 1000 mts of ascent the temperature decreases at the rate of 6.5°C.
2. Hence the places in the mountains are cooler than the places on the plains.
3. Even in South India places at higher altitude have cool climate.

Distance from the sea:

1. Distance from the sea not only causes temperature and pressure variations but also affects the amount of rainfall.
2. The entire area of peninsular region as it is surrounded by seas on three sides having the temperature equable throughout the year.
3. Areas of central and north India experiences much seasonal variation in temperature due to the absence of seas.

Monsoon winds:

1. The most dominant factor which affects the climate of India is the. monsoon winds.
2. India is influenced by the South west monsoon and North east monsoon from June to September and October, November respectively.
3. Indian agriculture is at the mercy of monsoons.
4. India experiences Tropical monsoon climate.

Relief:

1. Relief of India has a great bearing on major elements of climate such as temperature, atmospheric pressure direction of wind and amount of rainfall.
2. The mighty Himalayas in the north act as a climatic barrier preventing the freezing cold winds from central Asia away from India.
3. The Western ghats act as the barrier for south west monsoon winds causing rainfall to the western slopes, and the eastern slopes remain as rain shadow region.

Jet Stream:

1. Jet streams are the fast moving winds blowing in the narrow zone of upper layers of atmosphere.
2. These air currents play a dominant role in bringing the onset of South west monsoon and withdrawal of monsoon winds.
3. More over they are the main reason in bringing the Western Disturbances to the North Western part of Punjab and Haryana causing rainfall and enable the cultivation of winter wheat.
4. It causes snow fall in Jammu and Kashmir region.

Thus the Tropical monsoon = climate of India revolve around these factors

IX. Map Work

Mark the following on the outline map of India.

Question 1.
Areas of low rainfall
Answer:

Question 2.
Any 4 Biosphere Reserve
Answer:

Question 3.
Any 5 National parks
Answer:

Question 4.
Any 3 Wild animal sanctuary
Answer:

Question 5.
Any 2 Bird Sanctuary
Answer:

Question 6.
Top 5 states having maximum forest cover
Answer:

Question 7.
Top 5 states where forest cover is decreased
Answer:

Students can download 10th Social Science Geography Chapter 1 India: Location, Relief and Drainage Questions and Answers, Notes, Samacheer Kalvi 10th Social Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Social Science Solutions Geography Chapter 1 India: Location, Relief and Drainage

Samacheer Kalvi 10th Social Science India: Location, Relief and Drainage Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
The north-south extent of India is:
(a) 2,500km
(b) 292,933 km
(c) 3,214km
(d) 2,814km
Answer:
(c) 3,214km

Question 2.
The Southern most point of India is ……….
(a) Andaman
(b) Kanyakumari
(c) Indira Point
(d) kavaratti
Answer:
(c) Indira Point

Question 3.
The extent of Himalayas in the east-west is about:
(a) 2,500 km
(b) 2,400 km
(c) 800 km
(d) 2,200 km
Answer:
(a) 2,500 km

Question 4.
……… River is known as ‘Sorrow of Bihar’.
(a) Narmada
(b) Godavari
(c) Kosi
(d) Damodar
Answer:
(c) Kosi

Question 5.
Deccan Plateau covers an area of about sq.km.
(a) 8 lakh
(b) 6 lakh
(c) 5 lakh
(d) 7 lakh
Answer:
(d) 7 lakh

Question 6.
A landmass bounded by sea on three sides is referred to as ………
(a) Coast
(b) Island
(c) Peninsula
(d) Strait
Answer:
(c) Peninsula

Question 7.
The Palk Strait and Gulf of Mannar separates India from:
(a) Goa
(b) West Bengal
(c) Sri Lanka
(d) Maldives
Answer:
(c) Sri Lanka

Question 8.
The highest peak in South India is …………
(a) Ooty
(b) Kodaikanal
(c) Anaimudi
(d) Jindhagada
Answer:
(c) Anaimudi

Question 9.
Plains are formed by the older alluviums.
(a) Bhabar
(b) Tarai
(c) Bhangar
(d) Khadar
Answer:
(c) Bhangar

Question 10.
Pulicat Lake is located between the states of ………….
(a) West Bengal and Odisha
(b) Karnataka and Kerala
(c) Odisha and Andhra Pradesh
(d) Tamil Nadu and Andhra Pradesh
Answer:
(d) Tamil Nadu and Andhra Pradesh

II. Match the following

Answer:
A. (iii)
B. (i)
C. (v)
D. (ii)
E. (iv)

III. Give Reasons

Question 1.
The Himalayas are called young fold mountains.
Answer:
The Himalayas are called young fold mountains. Because they have been formed only few million years ago and also they were formed because of the folding of the Earth crust due to tectonic activity’.
[OR]
High pointed peaks and parallel ranges is the features of young fold mountains. Since the Himalayas have these features they are called young fold mountains.

Question 2.
North Indian Rivers are perennial.
Answer:
Most of the North Indian Rivers are perennial. It means that they have water throughout the year. These rivers receive water from rain as well as from melted snow from the lofty mountains.

Question 3.
Chottanagpur Plateau is rich in mineral resources.
Answer:
This region is a part of the ancient Gondwana region. So, Chotanagpur plateau is rich in mineral resources like iron ore and coal.

Question 4.
The great ludian desert ii called Marusthall.
Answer:
The Thar desert, also known as the Great Indian desert is a large arid region in the north
western part of the Indian Subcontinent that covers an area of 2,00,000 Km² and forms a natural boundary between India and Pakistan.
Marusthali means sand-dune. It covered eastern portion of the Great indian Thar Desert in western Rajasthan. It extends over about 24,000 square miles north of the Luni River.

Question 5.
The Eastern states are called seven sisters.
Answer:
The Eastern states in India are the continuous seven states. Assam, Arunachal Pradesh, Nagaland, Mizoram, Manipur, Tripura and Meghalaya. “A paradise unexplored” named by a journalist Jyothi Prakash Salkia in 1972 during the inaugural foundation of North East states.

Question 6.
The river Godavari is often referred to as Vridha Ganga.
Answer:

1. The Godavari is India’s second longest river after Ganga.
2. It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra.
3. It covers a large number of states as the Ganga does. Because of its large size and extend among the peninsular rivers, the river Godavari is often referred to as Vridha Ganga.

IV. Distinguish between the following

Question 1.
Himalayan rivers and Peninsular rivers.
Answer:
Himalayan Rivers:

1. Originate from the Himalayas.
2. Perennial in nature.
3. Long and Wide.
4. Middle and Lower courses are navigable.
5. Unsuitable for hydropower generation.

Peninsular Rivers:

1. Originate from Western ghats.
2. Non-perennial in nature.
3. Short and narrow.
4. Not useful for navigation.
5. Suitable for hydro-power generation.

Question 2.
Western Ghats and Eastern Ghats.
Answer:
Western ghats:

1. Western ghats forms the Western edge of the peninsular plateau.
2. It runs parallel to the Arabian sea coast.
3. They are continuous range.
4. Anaimudi is the highest peak.

Eastern ghats:

1. Eastern ghats form the Eastern edge of the peninsular plateau.
2. It runs parallel to the Bay of Bengal coast.
3. They are not continuous dissected by east flowing rivers.
4. Mahendragiri is the highest peak.

Question 3.
Himadri and Himachal.
Answer:
Himadri:

1. Northern most range of the Himalayas.
2. Known as the Greater Himalayas.
3. Lofty peaks like Mt.Everest, Kanchenjunga etc., are located in this range.
4. Region of permanent snow cover.

Himachal:

1. Middle range of the Himalayas.
2. Known as the lesser Himalayas.
3. Major hill stations like Shimla, Daijeeling etc., are located in this region.
4. Subjected to extensive erosion.

Question 4.
Western Coastal Plains and Eastern Coastal Plains.
Answer:
Western Coastal plains:

1. Lies between Western ghats and Arabian Sea.
2. It extends from Rann of Kutch in the North to Kanyakumari in the South.
3. Dotted with sandy beaches, lagoons and estuary.
4. It is known as Konkan plains in the North Kanara in the middle and Malabar in the South.

Eastern Coastal plains:

1. Lies between Eastern ghats and the Bay of Bengal.
2. It stretches along the states of West Bengal, Odisha, Andhra Pradesh and Tamil Nadu.
3. Has regular shoreline and composed of alluvial deposits.
4. Northern part (Mahanadhi-Krishna) called as Northern circars and Southern part (Krishna-Kaveri) is called Coromandal coast.

V. Answer in brief

Question 1.
Name the neighbouring countries of India.
Answer:
The neighbouring countries of India are Pakistan in the West, Afghanistan in the North-West, China, Nepal and Bhutan in the North and Bangladesh and Myanmar in the East and Srilanka in the South.

Question 2.
Give the importance of IST.
Answer:
To avoid the confusion of time in different states of India. One meridian is taken to have a uniform time for a whole country. Therefore 80° 30′ E has been chosen as the Standard Meridian of India which is almost passing from the centre of India.

Question 3.
Write a short note on Deccan Plateau.
Answer:

1. Deccan plateau is the largest part of the peninsular plateau.
2. It is roughly triangular in shape.
3. It covers an area of 7 lakh sq km.
4. The height ranges from 500 to 1000m above sea level.
5. It extends from Rajmahal hills on the East to Kanyakumari in the South. Satpura range in the West to Kanyakumari in the South. Bordered by Western Ghats on the West and Eastern ghats on the East.

Question 4.
State the west-flowing rivers of India.
Answer:

• The Narmada and the Tapi are the west flowing rivers of the Peninsular India.
• These rivers drain into the Arabian Sea.
• These rivers form estuaries on the west coast.
• These rivers are devoid of an large tributary system.
• Narmada river is the largest among the west flowing rivers of peninsular India. Its principal tributaries are Bushner, Halon, Heran, Banjar, Dudhi, Shakkar, Tawa, Bama and Kolar.
• Tapti river is one of only the three rivers in peninsular India that run from east to west. The others being the Narmada and the Mahi.
• The major tributaries are Vaki, Gomai, Arunavati, Aner, Nesu, Buray Panjhra and Bori. It outfall into the Arabian sea through the Gulf of Cambay.

Question 5.
Write a brief note on the island group of Lakshadweep.
Answer:

1. The Lakshadweep islands of India are located off the West coast of India.
2. These islands are of coral origin.
3. It covers an area of 32 sq km and consists of 27 islands.
4. Kavaratti is the administrative capital of Lakshadweep.
5. Earlier it had three divisions namely Laccadives, Minicoy and Aminidivi and was named as Lakshadweep in 1973.
6. “Pitt Island” of this group has a bird sanctuary and it is uninhabited.

VI. Answer In a paragraph

Question 1.
Explain the divisions of the Northern Mountains and its importance to India.
Answer:

• The Himalayas geologically young and structurally fold mountains stretch over the northern borders of India.
• The Himalayas represent the loftiest and one of the most rugged mountain barriers of the world.
• The mountain ranges run in a west-east direction from India to the Brahmaputra.

Question 2.
Give an account on the major peninsular rivers of India.
Answer:

1. The rivers in South India are called the Peninsular rivers.
2. Most of these rivers originate from the Western ghats.
3. These rivers are seasonal and are mainly fed by rain.
4. Based on the direction of flow the Peninsular rivers are divided into East flowing rivers and West flowing rivers.

East flowing rivers:

1. Mahanadi: Originates near Sihawa in Raipur district of Chattisgarh.
   • Flows through Odisha, Jharkand, Chattisgarh (851 km in length)
   • Major tributaries: Seonath, Telen, Sandur and lb.
   • Distributaries: Paika, Birupa, Chitartala, Genguti and Nun.
   • These distributaries forms the Delta of Mahanadhi, one of the largest delta in India.
   • This river flows into Bay of Bengal.

(ii) Godavari:

• It is the longest river (1,465km) among the peninsular rivers covers 3.13 lakh km2 area.
• Originates in Nasik district of Maharashtra.
• Flows through the States of Telangana and Andhra Pradesh ends into Bay of Bengal.
• Major distributaries: Puma, Penganga, Pranitha, Indravathi, Tal and Salami.
• Distributaries: Near Rajahmundry divides into two channels. Vasishta and Gautami and form one of the largest delta.
• Fresh water lake: Kolleru is located in the deltaic region of Godavari.

(iii) Krishna:

• It is the second longest peninsular river (1400 km) covers 2.58 lakh sq km area.
• Originates from a spring in Mahabaleshwar in the Western ghats of Maharashtra.
• Flows through Andhra Pradesh.
• Major tributaries: Bhima, Peddavagu, Musi, Koyna and Thungabhadra.
• Joins in Bay of Bengal at Hamasaladevi.

(iv) Kaveri:

• Originates at Talakaveri – Kudagu hills of Karnataka (800km).
• It is also known as Dakshin Ganga or Ganga of the South.
• Main Tributaries: Hemavathi, Kabini, Bhavani, Arkavathy, Amaravathi, Harangi etc.
• Distributary – Coleroon
• Sacred lslands made by river Kaveri: Sri ranagpattinam(Kamataka) Srirangam (TamilNadu) Waterfalls – Sivasamudram.
• Flows through Karnataka and TamilNadu.
• Enters TamilNadu through Hoghenekkal Falls (Dharmapuri).
• Drains into Bay of Bengal at Poompuhar.

West Flowing Rivers:

(i) Narmadha:

• Origin: Araarkantak Plateau (Madhya Pradesh)
• Length: 1312 km covers an area of 98,796 sq km.
• Largest among the West flowing rivers.
• Tributaries: Burhner, Halon, Heran, Banjar, Dudhi, Shakkar, Tawa, Bama, Kolar.
• States benefited: Madhya Pradesh, Maharashtra.
• Ends into Arabian Sea through the Gulf of Cambay.
• Forms 27 km long estuary.

(ii) Tapti:

• Rises near Multani in the Betul district of Madhya Pradesh.
• Length: 724 km. Covers an area of 65,145 sq km.
• Tributaries: Vaki, Gomai, Arunnavati, Aner, Nesu, Buray, Panjhra and Bori.
• Outfalls into the Arabian Sea through Gulf of Cambay.
• States: Flows through Madhya Pradesh and Maharashtra.
• Since all these rivers flow in the plateau region they are swift and are useful for hydro power generation.

Question 3.
Give a detailed account on the basin of the Ganga.
Answer:

• On the basis of deposition of Sediments by various rivers and topographical characteristics, the Northern plains of India is divided into the four major regions. Ganga plains is one among them.
• It extends from the Yamuna River in the West to Bangladesh in the East.
• The extensive plain is the largest plain of India covers 3.75 lakh sq. km.
• It is watered by the River Ganga and its tributaries such as Ghaghra, Gandak, Kosi, Yamuna, Chambal, Betwa etc.
• It is formed by the sediments of these rivers and is fertile in nature.
• The general slope of the entire plain is towards East and South-East.
• Ganga plains covers the states of Uttar Pradesh, Bihar and West Bengal.

VII. Map exercises

Mark the following in the outline map of India

Question 1.
Major mountain ranges – Karakoram,Ladakh, Zaskar, Aravaili, Western Ghats,Eastern Ghats.
Answer:

Question2.
Major rivers – Indus, Ganga, Brahmaputra, Narmada, Tapti, Mahanadi, Godavari, Krishna and Kaveri.
Answer:

Question 3.
Major plateaus – Malwa, Chotanagpur, Deccan.
Answer:

VIII. Activities

Question 1.
Observe the Peninsular Plateau map of India and mark the major plateau divisions of India.
Answer:

Question 2.
Prepare a table showing the major West flowing and East flowing rivers of peninsular India.
Answer:
West flowing rivers:

1. Narmada, Tapti, Mahi.
2. Flows into Arabian Sea through Gulf of cambay.
3. Do not make deltas but form estuary.

East flowing rivers:

1. Mahanadhi, Godhavari, Krishna and Kaveri.
2. Flows into Bay of Bengal.
3. Make deltas at their lower courses.

Question 3.
Assume that you are travelling from West Bengal to Gujarat along the beautiful coasts of India. Find out the states which you would pass through?
Answer:
From West Bengal, if we travel along the East coast we could pass through Odisha, Andhra Pradesh, Tamil Nadu states from North to South and from South to North along the West Coast we would pass through the states of Kerala, Karnataka, Goa, Maharashtra and reach Gujarat.

Question 4.
Find out the states through which the river Ganga flows.
Answer:
River Ganga flows through the States of Uttar Pradesh, Bihar and West Bengal.

Question 5.
Prepare a table showing the major rivers in India and findout it’s tributaries, origin, length and area.
Answer:

TB. PNo: 83
Find Out

Question 1.
The number of Union Territories along the western coast and eastern coast.
Answer:
Union Territories along the western coast are:

1. Diu and Daman
2. Dadra and Nagar Haveli
3. Mahe and Lakshadweep.

Union Territories along eastern coast are:

• Pondicherry and Andaman and Nicobar Islands.

Question 2.
Area wise which is the largest and the smallest state?
Answer:

1. Area wise Rajasthan is the largest state (3,42,239 sq.km).
2. The smallest state is Goa (3,702 sq km).

Question 3.
The states which do not have an international border or lie on the largest state.
Answer:
Haryana, Madhya Pradesh, Jharkhand, Chattisgarh.

Question 4.
Classify into four groups each having common frontiers with

1. Pakistan
2. China
3. Myanmar
4. Bangladesh.

Answer:

1. Pakistan – Jammu and Kashmir, Punjab, Rajasthan, Gujarat.
2. China – Jammu and Kashmir, Himachal Pradesh, Uttarkhand, Sikkim, Arunachal Pradesh.
3. Myanmar – Arunachal Pradesh, Nagaland Manipur, Mizoram.
4. Bangladesh – Meghalaya, Assam, West Bengal, Tripura.

TB. PNo: 85
Find Out

Question 5.
Find the Hill stations which are located in the Himalayan Mountains.
Answer:
Major hill stations of the Himalayas are Shimla, Mussoorie, Nainital, Almora, Ranikhet and Darjeeling.

TB. PNo: 95
Find Out

Question 6.
In which river the Gerosappa (jog) fall is found?
Answer:
In the river Sharavathi is the Gerosappa (jog) falls (830m). Second highest waterfalls in India.

Samacheer Kalvi 10th Social Science India: Location, Relief and Drainage Additional Important Questions and Answers

I. Choose the correct answer

Question 1.
India is the ………………… largest country in Asia.
(a) first
(b) second
(c) fourth
(d) third
Answer:
(b) second

Question 2.
Along with Hindukush and Karakoram range ……… provide a natural boundary in the
north.
(a) Aravalli
(b) Satpura
(c) Himalayas
Answer:
(c) Himalayas

Question 3.
The ………………… latitude passes through the middle of the country.
(a) 0°
(b) 23°.30’N
(c) 66°.30’N
(d) 23°.30’S
Answer:
(b) 23°.30’N

Question 4.
The coconut bearing coastal plains are on the ………
(a) east
(b) west
(c) south
Answer:
(c) south

Question 5.
The ………………… is known as the “Roof of the World”.
(a) Armenian knot
(b) Anaimudi
(c) Pamirknot
(d) Mt.Everest
Answer:
(c) Pamirknot

Question 6.
The …….. land gets abundance sunshine from the sun.
(a) mediterranean
(b) tropical
(c) equatorial
Answer:
(b) tropical

Question 7.
The Great Northern plains covers an area of over sq.km.
(a) 5 lakh
(b) 6 lakh
(c) 7 lakh
(d) 8 lakh
Answer:
(c) 7 lakh

Question 8.
The …… divides India into two halves.
(a) tropic of Cancer 231/2° N
(b) equator 0°
(c) tropic of Capricorn 231/2° S
Answer:
(a) tropic of Cancer 231/2° N

Question 9.
The ………………… desert is the world 9th largest sub tropical desert.
(a) Gobi
(b) Atacama
(c) Kalahari
(d) Thar
Answer:
(d) Thar

Question 10.
India is …….. times bigger than Pakistan.
(a) two
(b) five
(c) four
Answer:
(c) four

II. Match the following

Question 1.
Match the Column I with Column II.

Answer:
A. (iii)
B. (i)
C. (v)
D. (ii)
E. (iv)

Question 2.
Match the Column I with Column II.

Answer:
A. (iv)
B. (v)
C. (ii)
D. (iii)
E. (i)

III. Give Reasons

Question 1.
Peninsular Rivers are Non-Perennial.
Answer:
Peninsular rivers originate from the Western Ghats. They have a large seasonal fluctuation in the volume of water as they are solely fed by the rain. So these Rivers are seasonal and non-perennial.

Question 2.
Andaman and Nicobar islands have dense forests.
Answer:
Since these islands lie close to the equator, the climate remains hot and wet throughout the year and has dense forests.

Question 3.
India has close contact with the countries of the West and the East.
Answer:
India’s Southward extension along the Indian ocean and the trans Indian . ocean routes provide a strategic position to India connecting the countries of Europe in the West and the countries of East Asia. Thus, India has close contact with the countries of the West and the East.

Question 4.
India is geographically vibrant and incredible country.
Answer:
The majestic Himalayan peaks in the North, beautiful beaches in the South, the Great Indian desert in the West and the breathtaking natural heritage in the East make India geographically vibrant and an incredible country.

IV. Distinguish between the following

Question 1.
Andaman and Nicobar Islands and Lakshadweep Islands.
Answer:
Andaman and Nicobar Islands:

1. Located in Bay of Bengal.
2. These islands are of volcanic origin.
3. Port Blair is the administrative capital.
4. Consists of nearly 572 islands.

Lakshadweep Islands:

1. Located in Arabian Sea off the West coast of India.
2. These islands are mainly coral origin.
3. Kavaratti is the administrative capital.
4. Consists of nearly 27 islands.

Question 2.
Bhangar plains and Khadar plains.
Answer:
Bhangar plains:

1. Upland alluvial tracts of Great plains.
2. Formed by the older alluvium.
3. Soil is dark, rich in humus.
4. Well drained and fit for agriculture.

Khadar plains:

1. Plains along the courses of the rivers of Great plains.
2. Formed by the newer alluvium.
3. Soil is sandy, silt, clay and mud.
4. Highly fertile.

Question 3.
West flowing rivers and East flowing rivers.
Answer:
West flowing rivers:

1. Flow into Gulf of Cambay.
2. Form estuaries
3. Narmadha, Tapti and Mahi are the major west flowing rivers.

East flowing rivers of Peninsular plateau or South India:

1. Flow into Bay of Bengal.
2. Form Deltas
3. Mahanadhi, Godavari, Krishna and Kaveri are the major east flowing rivers.

Question 4.
Tributary and Distributary.
Answer:
Tributary:

1. A river or stream that joins with the main river.
2. Contributes water to the main river.
3. Eg: Yamuna tributary of river Ganga.

Distributary:

1. A branch or outlet that leaves the main river.
2. Carries water to the sea or lake.
3. Eg: River Coleroon a distributary of river Kaveri.

V. Answer in brief

Question 1.
Mention the tributaries of Godavari.
Answer:
Ghatprabha, Malaprabha, Manjira, Penganga and Neingarga.

Question 2.
Name the boundaries of India.
Answer:
India is bounded by Bay of Bengal on the East, Arabian sea on the West, Indian ocean in the South and the lofty Himalayas in the North

Question 3.
Why do we need a Standard Meridian for India?
Answer:
To avoid time gap of two hours between east and west part of India which may create confusion in working, it is essential to have a Standard Meridian.

Question 4.
How India is politically divided?
Answer:
India is politically divided into 29 states and 7 union territories (Delhi being the National Capital territory) for administrative convenience.

Question 5.
Why is India called a Sub-continent? How it is separated?
Answer:

1. India is called a Sub-continent because it is big landmass, which stands out as a distinct geographical unit from the rest of the continent.
2. It is separated by natural features like mountains and rivers.
3. India is also separated from rest of the continent by the mighty Himalayas.

Question 6.
Name the three major divisions of the Northern Mountains.
Answer:
The three major divisions of the Northern mountains are:

1. The Trans-Himalayas (or) The Western Himalayas
2. The Himalayas
3. Eastern Hills or Purvanchal Hills

Question 7.
Why is Northern Plain most productive part of India?
Answer:
With a rich soil cover combined with an adequate water supply and favourable climate Northern plain is agriculturally a very productive part of India.

Question 8.
How has Northern Plain become a fertile Plain?
Answer:
The plain is formed of alluvial soil. The deposition of alluvium in a large basis lying at the foothills of the Himalayan over millions of years make northern plains fertile.

VI. Answer in a paragraph

Question 1.
India is a Sub-Continent. Prove it.
Answer:

1. Physical features
2. Climate conditions
3. Natural vegetation
4. Cultural norms
5. Ancient ethic and linguistic groups
6. Huge area

All these distinctive continental characteristic are found in India. Hence we consider India as a Sub-Continent.

Question 2.
Name the old fold mountain in India and write a brief note on it.
Answer:

1. Aravalli range is the old fold mountain in India.
2. These mountains are the relies and are reduced into hills due to erosional features.
3. The Aravalli hills form the North-Western and Western boundary of the Central Highlands a sub division of Peninsular plateau.
4. These hills extends from Gujarat through Rajasthan to Delhi in the North westerly direction (700km).
5. The height of these hills is about 1500m in South west and near Delhi hardly 400m.
6. Gurushikar (1722m) is the highest peak of this range.

Question 3.
Write a note on Purvanchal Hills.
Answer:

1. They are the eastern off-shoot of Himalayas.
2. It extended in the north-eastern states of India.
3. Most of these hills are located along the border of India and Myanmar while others are inside India.
4. Dafla Hills, Abor Hills, Mishmi Hills, Patkai Bum Hills, Naga Hills, Manipur Hills, Mizo Hills, Tripura Hills, Mikir Hills, Garo Hills, Khasi Hills and Jaintia Hills are the hills which are collectively known as Purvanchal Hills.

Question 4.
Write in general about the structure of the Peninsular plateau.
Answer:

1. The peninsular plateau lies to the south of the Great Northern plains.
2. This is the largest physiographic division covers an area of about 16 lakh sq.km.
3. It is made up of old rocks and consists of series of plateaus and hill ranges interspersed with river valleys.
4. The average height of a large portion of this plateau is more than 600m.
5. Anaimudi is the highest point of this place located in Anaimalai.
6. The plateau slopes towards east and is a part of ancient Gondwana.
7. River Narmada divides the Plateau region into two. The region lying to the north of Narmada is called Central Highlands and South of Narmada is called Deccan plateau.

VII. Map exercises

Question 1.
Mark the following in the outline map of India.

Set 1:

1. Mark the boundaries of India
2. Latitudinal Extent
3. Longitudinal Extent
4. Tropic of cancer
5. Lakshadweep Islands
6. Andaman and Nicobar Islands
   
7. Central Meridian of India
   

Set 2:
Peaks: Anaimudi, Mt. Everest, Mt.K2 Mahendragiri, Gurushikhar. NamchaBarwa, Nanga parbat, Kanchenjunga. Dhaulagiri, Makalu. Nandadevi, Dodabetta.

Hill stations: Shimla, Mussourie Ranikhet, Nainital, Almora, Darjeeling.

Hills: Aravalli, Vindhya. Satpura, Naga hills, Mizo hills, Garo hills, Khasi hills, Jaintia hills, Nilgiri hills, Anaimalai hills, Cardomom hills, Raj Mahal hills, Gir hills.

Gulf: Gulf of Mannar, Gulf of Kutch, Rann of Kutch, Palk Strait, Gulf of Cambay.

Set 3:
Seven Union Territories:

1. Delhi
2. Chandigarh
3. Diu and Daman
4. Dadra and Nagar Haveli
5. Pondicherry
6. Andaman and Nicobar Islands
7. Lakshadweep.