Chapter 2: Inside Our Earth

Geography • Class 7

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Chapter Analysis

Beginner6 pages • English

Quick Summary

The chapter 'Inside Our Earth' in Class 7 Geography explores the dynamic nature of the earth, describing its interior structure consisting of the crust, mantle, and core. It explains the three types of rocks: igneous, sedimentary, and metamorphic, and how they form and transform through the rock cycle. The chapter discusses the significance of rocks and minerals, as well as their usage in various aspects of daily life.

Key Topics

  • Earth's structure
  • Constituents of the crust
  • Types of rocks
  • Rock cycle
  • Uses of rocks
  • Mineral composition
  • Natural processes
  • Tectonic activities

Learning Objectives

  • Understand the structure of the earth
  • Identify different types of rocks and their formation
  • Explain the rock cycle
  • Recognize the uses of rocks and minerals in daily life
  • Appreciate the dynamic nature of the earth
  • Analyze geological processes and their impact

Questions in Chapter

What are the three layers of the earth?

Answer: The three layers of the earth are the crust, mantle, and core.

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What is a rock?

Answer: A rock is any natural mass of mineral matter that makes up the earth’s crust.

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Name three types of rocks.

Answer: The three types of rocks are igneous rocks, sedimentary rocks, and metamorphic rocks.

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How are extrusive and intrusive rocks formed?

Answer: Extrusive igneous rocks are formed when molten lava comes on the earth’s surface and cools rapidly. Intrusive igneous rocks are formed when the molten magma cools down deep inside the earth's crust.

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What do you mean by a rock cycle?

Answer: Rock cycle is the process of transformation of one type of rock to another under certain conditions in a cyclic manner.

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What are the uses of rocks?

Answer: Rocks are used for making roads, houses, buildings and also have industrial and cultural uses.

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What are metamorphic rocks?

Answer: Metamorphic rocks are formed under great heat and pressure from either igneous or sedimentary rocks.

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Additional Practice Questions

What defines the crust of the earth and its importance?

easy

Answer: The crust is the outermost layer of the earth, characterized by its relative thinness compared to other layers. It is crucial as it forms the continents and ocean floors where diverse ecosystems flourish.

How does the mantle differ from other layers of the earth?

medium

Answer: The mantle extends up to 2900 km below the crust and is composed mostly of silicate rocks richer in magnesium and iron than the crust. It is vital in understanding tectonic plate movements.

Explain the significance of the rock cycle in geology.

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Answer: The rock cycle illustrates how rocks transform from one type to another over geological time, driven by processes like melting, cooling, eroding, compacting, and deforming. This cycle is fundamental in understanding earth's continual reshaping.

Why are sedimentary rocks important for paleontologists?

hard

Answer: Sedimentary rocks often contain fossils, the preserved remains of ancient organisms, which are key to studying past life forms and understanding the earth's historical climate and ecosystems.

What are the implications of the presence of minerals in daily life?

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Answer: Minerals are crucial for numerous applications, including in construction, manufacturing of gadgets, and as dietary nutrients. Minerals like iron and aluminum are essential in making vehicles and appliances.