NCERT Solutions Class 7th Geography Social Science Chapter- 2 Inside Our Earth Question & Answer

May 11, 2022

NCERT Solutions Class 7th Geography Social Science Chapter- 2 Inside Our Earth

Textbook	NCERT
Class	7^th
Subject	Geography Social Science
Chapter	Chapter – 2
Chapter Name	Inside Our Earth
Category	Class 7th Social Science Geography
Medium	English
Source	Last Doubt

NCERT Solutions Class 7th Geography Social Science Chapter- 2 Inside Our Earth Question & Answer What is inside in our earth?What is the earth ? What can we learn from inside our earth? Where are we inside Earth? How old is our Earth? How old is the Earth kids? How old is Earth born? What age is Earth? Is the Earth 1000 years old? What is the first life on Earth? When was Earth first called? Who named Earth? What is Earth’s real name? Who gave Earth its name? How big is Earth? How did Earth get water? Does Earth have a symbol? What is our Sun called? What are 5 facts about Earth? What is Earth made of? What is rock ? What is lava ? How deep is Earth?

NCERT Solutions Class 7th Geography Social Science Chapter -2 Inside Our Earth

Chapter -2

Inside Our Earth

Question &Answer

Answer the following questions briefly.

Question. 1. What are the three layers of the earth?

Answer- Three Layers of the Earth

(a) Crust
(b) Mantle
(c) Core.

Question. 2. What is a rock?

Answer- 2 Rock

• A mass of mineral matter that makes up the crust of the earth is called rock.
Or
• Aggregates of minerals are termed as rocks.

Examples- See part

Question. 3. Name three types of rocks.

Answer- Three Types of Rocks

• Igneous Rocks
• Sedimentary Rocks
• Metamorphic Rocks.

Question. 4. How are extrusive and intrusive rocks formed?

Answer- Formation of Extrusive and Intrusive Rocks

• Due to extreme heat in the interior of the earth, rocks are found in the form of molten material called magma.

• When magma comes out on the surface of the earth, it cools down and turns into solid rocks. Such rocks are termed as extrusive rocks.

Examples-

• Basalt.
• Deccan Trap is built of basalt.

• When the molten magma cools down within the interior of the earth, it becomes solid to form intrusive rocks.

Examples-

• Granite.
• Gabro.

Question. 5. What do you mean by a rock cycle?

What are the uses of rocks?
What are metamorphic rocks?

Answer- Rock Cycle

• Igneous rocks change into sedimentary rocks, igneous and sedimentary rocks under heat and pressure change into metamorphic rocks, metamorphic rocks into igneous rocks or sedimentary rocks due to melting or wearing down. This process is called the rock cycle.6 Uses of Rocks

• Hard rocks are used in making buildings and barrages.
• Houses and buildings are built of rocks (stones, slates, granite, marble).
• Stones are used in numerous games:
• Seven stones (phitthoo).
• Hopscotch (stapu, kit).
• Five stones (gitti).

• Rocks (stones and slates) are used in building bridges, embankments.7 Metamorphic Rocks

• When under heat and pressure igneous rocks and sedimentary rocks change their form and more precious rocks are formed to be known as metamorphic rocks.

Examples-

Granite into granite gneiss.
Coal into slate.
Slate into schist.
Limestone into marble.

Question 2. Tick the correct answer.

(i) The rock which is made up of molten magma is

(a) Igneous
(b) Sedimentary
(c) Metamorphic.

Answer- (a) Igneous

(ii) The innermost layer of the earth is

(a) Crust
(b) Core
(c) Mantle.

Answer- (b) Core

(iii) Gold, petroleum and coal are example of

(a) Rocks
(b) Minerals
(c) Fossils.

Answer- (b) Minerals

(iv) Rocks which contain fossils are

(a) Sedimentary rocks
(b) Metamorphic rocks
(c) Igneous rocks.

Answer- (a) Sedimentary rocks

(v) The thinnest layer of the earth is

(a) Crust
(b) Mantle
(c) Core.

Answer- (a) Crust

Question.3. Match the skill:

Column A	Column B
(i) Core	(a) Earth’s surface
(ii) Minerals	(b) Used for roads and buildings
(iii) Rocks	(c) Made of silicon and alumina
(iv) Clay	(d) Has definite chemical composition
(v) Sial	(e) Innermost layer
	(f) Changes into slate
	(g) Process of transformation of the rock

Answer-

Column A	Column B
(i) Core	(e) Innermost layer
(ii) Minerals	(d) Has definite chemical composition
(iii) Rocks	(b) Used for roads and buildings
(iv) Clay	(f) Changes into slate
(v) Sial	(c) Made of silicon and alumina

Question 4.Give reasons:

(i) We cannot go to the centre of the earth.
(ii) Sedimentary rocks are formed from sediments.
(iii) Limestone is changed into marble.

Answer-

• We cannot go to the centre of the earth because of the following reasons:

1.The thickness (from crust to the core) is 6371 km. (Radius of the earth).
2.Temperature increases with depth @ 1°C per 32 metre.
3.There is extreme heat and pressure of overlying rocks, everything is in a molten state.
4.There is no oxygen to survive.

• Sedimentary rocks are formed from sediments because of the following reasons:

1.Igneous rocks and metamorphic rocks, decompose, disintegrate and wear down due to weathering.
2.This material is carried away by running water (rivers), wind, glacier.
3.The material is then deposited in low lying areas and is called sediments.
4.When sediments are solidified into layers due to pressure from overlying sediments they are called sedimentary rocks.

• Limestone is changed into marble due to the following reasons:

1.The overlying layers of rocks put pressure on the underlying rocks.
2.From the surface to the interior of the earth, temperature and heat go on increasing.
3.Due to pressure and heat, the original limestone changes into marble.

NCERT Solution Class 7th Geography All Chapters Question Answer

Chapter – 1 Environment

Chapter – 2 Inside Our Earth

Chapter – 3 Our Changing Earth

Chapter – 4 Air

Chapter – 5 Water

Chapter – 6 Human-Environment Interactions – The Tropical and the Subtropical Region

Chapter – 7 Life in the Deserts

NCERT Solution Class 7th Geography All Chapters Notes

Chapter – 1 Environment

Chapter – 2 Inside Our Earth

Chapter – 3 Our Changing Earth