NCERT Solutions Class 7 Social Science Geography Inside Our earth

Scroll down for PDF

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

1. Answer the following questions: 

(i) What are the three layers of the earth? 

Ans. The three layers of the earth are: 

(a) Crust 

(b) Mantle

(c) Core 

(ii) What is a rock? 

Ans. Any natural mass of mineral matter that makes up the earth’s crust is called rock. 

(iii) Name three types of rocks. 

Ans. The three types of rocks are: 

(a) Igneous Rocks 

(b) Sedimentary Rocks, and 

(c) Metamorphic Rocks 

 

(iv) How are extrusive and intrusive rocks formed? 

Ans. Rocks that are formed when molten magma solidifies on the earth’s crust are known as extrusive igneous rocks. Sometimes, the molten magma cools down deep inside the earth’s crust. The rocks so formed are known as intrusive igneous rocks. 

(v) What do you mean by a rock cycle? 

Ans. The process of transformation of rock from one type to another is known as rock cycle. 

(vi) What are the uses of rocks? 

Ans. Rocks are very useful to us. They are used for making roads, houses, buildings, bridges, etc. They are also used to make decorative items such as vases, boxes, statues, etc. 

(vii) What are metamorphic rocks? 

Ans. When igneous or sedimentary rocks are subjected to high temperature and pressure, they are converted into metamorphic rocks. For example, clay changes into slate and limestone into marble. 

2. Tick the correct answer. 

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

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

(ii) The innermost layer of the earth is 

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

(iii) Gold, petroleum, and coal are examples of 

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

(iv) Rocks which contain fossils are 

(a) Sedimentary Rocks 

(b) Metamorphic Rocks 

(c) Igneous Rocks 

(v) The thinnest layer of the earth is 

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

3. Match the following. 

(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) Have definite chemical composition 

(v) Sial           (e) Innermost layer 

                       (f) Changes into slate 

                       (g) Process of transformation of the rock      

Ans. 

(i) Core           (e) Innermost layer 

(ii) Minerals     (d) Have 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 

 

5. Give reasons. 

(i) We cannot go to the centre of the earth. 

Ans. The centre of the earth is characterised by very high temperature and pressure, which does not allow the survival of any living being. Thus, it is impossible for anyone to reach the centre of the earth. 

(ii) Sedimentary rocks are formed from sediments. 

Ans. Rocks strike each other and are broken down into small sediments. These sediments are transported and deposited by natural agents like wind, water, etc. Overtime, these loose sediments are compressed and hardened to form rocks, which are known as sedimentary rocks. 

(iii) Limestone is changed into marble. 

Ans. When igneous and sedimentary rocks are subjected to high temperature and pressure, they are converted into metamorphic rocks. Limestone is a sedimentary rock, which after going through such a process is converted into marble, a metamorphic rock. 

5. For fun. 

(i) What are the minerals most commonly used in the following objects? 

Ans.  

(a) Karhai - Aluminium 

(b) Pan/Tava – Iron 

(c) Ornaments – Gold 

(d) Bell – Silver 

(e) Hammer – Iron 

(f) Lamp – Copper 

 

(ii) Identify some more objects made up of different minerals. 

Ans. Some other objects made up of minerals are: 

(a) Pencil lead – Graphite 

(b) Mirror – Quartz 

(c) Trash can – Chromite 

(d) Wires - Copper 

Tags: 

Click on the text For more study material for Social Science please click here - Social Science

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

Requirements for admissions in CBSE affiliated Schools

CBSE gives an advanced form of education. They try to indulge students in interactions and teach application based subjects along with some others. Due to this preponderance of parents, they tend to admit their children in CBSE affiliated schools. General conditions...

CBSE examination board hike the fee for class 10th and 12th

The CBSE (Central Board Secondary Education) increased the examination fees for classes 10 and 12 of the 2020 boards, with no profit no loss principle, from Rs. 750 to Rs 1500, for all categories of students, including SC/ST candidates for all schools throughout India...

CBSE Board Introduces Experiential Learning for Student

CBSE Academic Session 2019-20: Board Introduces Experiential Learning for Student: The education sector has grown for some new changes. As per the latest updates the Central Board of Secondary Education has been good in making all the possible efforts to improve...

CBSE DATE SHEET 2020

Central Board of Secondary Education, CBSE is to conduct the 10th and 12th Board Examination 2020 from February 15, 2020. Due to University Admissions, CBSE has shifted Board Exams dates from 1 March to February 15 from 2019. This year too CBSE would be making changes...

JEE in Punjabi too after English, Hindi and Gujarati

Punjab Minister Tript Rajinder Singh Bajwa requested the joint technology entrance exam (main) to be conducted in Punjabi and other regional languages too. In his letter to Union HRD Minister Ramesh Pokhriyal Nishank, the Punjab Minister for Higher Education and...

×
Studies Today