Rocks

Question 1

What are the three main components of Earth

Answer 1

Lithosphere
hydrosphere
atmosphere

Question 2

What is biosphere

Answer 2

Biosphere is the area/region in which all the three main components of Earth interact meet and overlap
This is the zone in which most living creatures exist

Question 3

Types of forces on the earth surface

Answer 3

Internal and external

Question 4

What do external forces do

Answer 4

They smoothen the landforms on the earth surface
example-
wind and running water

Question 5

What do internal forces do

Answer 5

they originate under the Earth’s surface

They are related to the volcanoes and earthquakes

Question 6

What are rocks

Answer 6

Rocks are aggregates of minerals with no definite chemical composition
They form most of the solid material in the lithosphere

Question 7

What is a mineral

Answer 7

Minerals are the raw materials of rocks
They have a definite chemical composition, chemical properties and physical properties
Example-
Silicates and quartz

Question 8

Rocks that contain metals in large quantities are known as

Answer 8

Ores

Question 9

Importance of rocks

Answer 9

Rocks are used for building material
They supply raw materials for manufacturing industries
They supply precious metals such as gold and silver
On disintegration they form smaller particles which are known as soil

Question 10

Types of rocks

Answer 10

Igneous
metamorphic
sedimentary

Question 11

Other name for igneous rocks

Answer 11

Parent rocks

Primary rock

Question 12

How are igneous rocks formed

Answer 12

Igneous rocks are formed when molten magma produced from a volcano solidifies and crystallizes inside the Earth or on the Earth’s surface

Question 13

Why are igneous rocks called parent rocks

Answer 13

Igneous rocks make up 85% of the earth’s crust

They help in the formation of sedimentary rocks

Question 14

Types of igneous rocks

Answer 14

Intrusive igneous rocks

Extrusive igneous rocks

Question 15

Example of intrusive igneous rock

Answer 15

Granite and gabbro

Question 16

Example of extrusive igneous rocks

Answer 16

Basalt and Pumice

Question 17

Characteristics of igneous rocks

Answer 17

Igneous rocks are granular and crystalline
They are hard and compact
They are non fossiliferous
They do not wear out easily
They do not have layers

Question 18

Uses of igneous rocks

Answer 18

Jewellery making-obsidian
flooring and kitchen worktop- granite
Used as concrete- basalt

Question 19

What are intrusive igneous rocks

Answer 19

Igneous rocks the Magma that solidify is under great pressure inside the earth

Question 20

What are extrusive igneous rocks

Answer 20

Extrusive igneous rocks are igneous rocks that get formed on the Earth’s surface when Magma rapidly cools and solidifies

Question 21

What are sedimentary rocks

Answer 21

sedimentary rocks are rocks that are formed when the waste products of the older rocks get broken down by agents of denudation such as wind running water and glacier

They are found in lakes and oceans

They are formed in layers or strata

Question 22

Types of sedimentary rocks

Answer 22

Mechanically formed-sandstone shale and clay
Chemically formed - rock salt and gypsum
organically formed - coal and petroleum

Question 23

Characteristics of sedimentary rocks

Answer 23

They are in layers
they contain fossils
they are not crystalline and not very hard
they are permeable rocks