Worksheet Solutions: The Interior of the Earth | Window on the Word Class 7: Solutions, Notes & Worksheets PDF Download

Q1: Multiple Choice Questions (MCQs)

(i) What are the three main layers of the Earth?
(a) Crust, Mantle, Inner Core
(b) Core, Lithosphere, Asthenosphere
(c) Mantle, Oceanic Crust, Continental Crust
(d) Crust, Mantle, Core
Ans: (d)
The Earth's main layers are the crust, mantle, and core.

(ii) Which type of rock forms from cooled and solidified lava?
(a) Sedimentary
(b) Metamorphic
(c) Igneous (extrusive)
(d) Igneous (intrusive)
Ans: (c)
Igneous rocks formed from cooled lava on the Earth's surface are known as extrusive igneous rocks.

(iii) What is the composition of the continental crust?
(a) Silica and Aluminium
(b) Silica and Magnesium
(c) Nickel and Iron
(d) Iron and Aluminium
Ans: (a)
The continental crust is mainly composed of silica and aluminium, also known as sial.

(iv) Which layer of the Earth is predominantly semi-solid molten rock?
(a) Core
(b) Mantle
(c) Crust
(d) Inner Core
Ans: (b)
The mantle is mostly composed of semi-solid molten rock called magma.

(v) What type of rock is formed when intense heat and pressure transform existing rocks?
(a) Sedimentary
(b) Metamorphic
(c) Igneous (extrusive)
(d) Igneous (intrusive)
Ans: (b)
Metamorphic rocks are formed when existing rocks undergo high heat and pressure, causing them to transform into a new type of rock.

Q2: Fill in the Blanks

(i) The thinnest layer of the Earth is the ____________.
Ans: Crust
The crust is the outermost and thinnest layer of the Earth.

(ii) The Earth's core is primarily composed of ____________ and ____________.
Ans: Nickel, Iron
The core is mainly made up of nickel and iron.

(iii) ____________ rocks are formed when magma gets trapped under the crust and cools down slowly.
Ans: Intrusive
Intrusive igneous rocks form from slowly cooled magma beneath the surface.

(iv) Limestone is an example of a ____________ rock.
Ans: Sedimentary
Limestone is a type of sedimentary rock.

(v) Metallic minerals are mainly found in ____________ rocks.
Ans: Igneous
Metallic minerals are primarily found in igneous rocks.

Q3: Match the Column

Ans:

Q4: True or False

(i) The mantle makes up over three-fourths of the Earth's volume.
Ans: True
This statement is true. The mantle makes up more than three-fourths of the Earth's volume.

(ii) The oceanic crust is thicker than the continental crust.
Ans: False
This statement is false. The oceanic crust is thinner than the continental crust.

(iii) Sedimentary rocks are primarily formed from cooled magma.
Ans: False
This statement is false. Sedimentary rocks are formed from compressed and hardened sediments, not cooled magma.

(iv) Marble is an example of an igneous rock.
Ans: False
This statement is false. Marble is a type of metamorphic rock, not igneous.

(v) Metallic minerals are mainly found in sedimentary rocks.
Ans: False
This statement is false. Metallic minerals are primarily found in igneous rocks.