Balbharti Maharashtra State Board Class 9 Geography Solutions Chapter 3 Exogenetic Movements Part 1 Notes, Textbook Exercise Important Questions and Answers.

Class 9 Geography Chapter 3 Exogenetic Movements Part 1 Textbook Questions and Answers

1. Answer in brief.
(a) What is mechanical weathering?
Answer:

(b) What are the main types of chemical weathering?
Answer:
The process of decomposition of rocks due to changes in their chemical composition is called chemical weathering.
Its main types are:
(i) Carbonation

(ii) Solution

(iii) Oxidation

(c) How does biological weathering occur?
Answer:

(d) Distinguish between weathering and mass wasting.
Answer:

2. Write whether the statements are true or false. Correct the incorrect ones.

(a) Climate affects earthquakes.
Answer:
False – Internal movements affect (leads to) earthquakes.

(b) Mechanical weathering is less effective in humid climates.
Answer:
True

(c) Mechanical weathering happens on a large scale in dry climates.
Answer:
True

(d) The breaking down of rocks into smaller particles is called weathering.
Answer:
True

(e) Lateritic rocks are formed through exfoliation.
Answer:
False – Lateritic rocks are formed due to oxidation.

3. Complete the flowchart below.

4. Identify the type of weathering from the given description.

(a) Some animals live inside the grounds by making burrows.
(b) The rock rusts.
(c) Water which has accumulated in the crevices of the rocks freezes. Consequently, the rock breaks.
(d) The pipes supplying water in colder regions break.
(e) Sand formation occurs in deserts
Answer:
(a) Biological weathering
(b) Chemical weathering
(c) Mechanical weathering
(d) Mechanical weathering
(e) Mechanical weathering

Class 9 Geography Chapter 3 Exogenetic Movements Part 1 Intext Questions and Answers

Can You Tell?
(1) See the given pictures. Observe the physical appearance of the rocks in each picture. You can see that rocks are broken, fractured and have holes in them. In a picture you can also see that the statue has been deformed. Why are the rocks in such a condition? Think about them and briefly tell the reasons you can think of. Discuss the reasons. Check with the teachers if your reasons are relevant.
Answer:

Lets Recall

Question 1.
Have you seen the process of biological weathering3 around you?
Answer:
I have seen process of biological weathering3 around me. Many plants and trees have grown in an old dilapidated building which is located near my house. The roots of the trees have broken the walls and slabs of the building at many places.

Class 9 Geography Chapter 3 Exogenetic Movements Part 1 Additional Important Questions and Answers

Complete the statements choosing the correct option from the bracket:

Question 1.
…………………… is formed due to chemical precipitation between water and alkalis.
(a) Limestone
(b) Sandstone
(c) Coal
(d) Iron
Answer:
(a) Limestone

Question 2.
…………………… process occurs in rocks which have iron present in them.
(a) Shattering
(b) Oxidation
(c) Carbonation
(d) Granular
Answer:
(b) Oxidation

Question 3.
Sometimes the weathered materials do not move downward but sink ‘in situ’. This is called ………………….. .
(a) carbonation
(b) exfoliation
(c) precipitation
(d) slumping
Answer:
(d) slumping

Question 4.
periglacial regions along the slopes, small layers of soil accumulate because of the movement of soil. This is called ………………….. .
(a) soil erosion
(b) solifluction
(c) shattering
(d) block disintegration
Answer:
(b) solifluction

Question 5.
Biological weathering occurs because of ………………….. .
(a) high temperatures
(b) frost
(c) crystal growth
(d) living organisms
Answer:
(d) living organisms

Question 6.
come minerals in the rock get dissolved in the water and undergo chemical weathering. This process is called ………………….. .
(a) solution
(b) carbonation
(c) exfoliation
(d) precipitation
Answer:
(a) solution

Question 7.
When dilute carbonic acids reacts with the minerals in the rocks the process is called as ………………….. .
(a) carbonation
(b) exfoliation
(c) precipitation
(d) slumping
Answer:
(a) carbonation

Question 8.
When the outer layers of the rock fall apart from the main rock due to difference in temperatures, the process is called ………………….. .
(a) shattering
(b) oxidation
(c) exfoliation
(d) carbonation
Answer:
(c) exfoliation

Question 9.
…………………… is a universal solvent¹.
(a) Soil
(b) Water
(c) Carbon
(d) Oxygen
Answer:
(b) Water

Question 10.
Alkalis in the rock dissolve because of the solution and make them ………………….. .
(a) even
(b) sturdy
(c) brittle
(d) crusty
Answer:
(c) brittle

Match the Column:

I.

Answer:
(1-b),
(2- c),
(3 – a)

II.

Answer:
(1 – c),
(2 – d),
(3 – a)

Answer in one sentence each;

Question 1.
What are the Exogenetic processes?
Answer:
Exogenetic processes are external processes 1 that occur on or above the earth’s surface, E.g. weathering, erosion, transportation, deposition etc.

Question 2.
Explain the Process of weathering
Answer:
Breaking or weakening of rocks is called as weathering.

Question 3.
What is Mechanical Weathering?
Answer:
The disintegration of rocks without any change in their chemical composition is called mechanical weathering.

Question 4.
What is Chemical Weathering (Salt Weathering)?
Answer:
The process of decomposition of rocks due to changes in their chemical composition is called chemical weathering.

Question 5.
What do you mean by Biological Weathering?
Answer:
The weathering process caused by human beings, animals and plants is called biological weathering.

Question 6.
What is Slumping?
Answer:
Sometimes the weathered materials do not move downward but sink ‘in situ’ (where they ! are). This is called slumping. ;

Question 7.
What is Solifluction?
Answer:
In periglacial regions along the slopes, small layers of soil accumulate because of the movement of soil. This is called solifluction.

Question 8.
Explain Granular Weathering.
Answer:
When water penetrates in rocks like sandstones and conglomerates1, the particles get loose and separate from the main rock. This is called granular weathering.

Question 9.
What is Block Disintegration?
Answer:
When water accumulates in wide points and big blocks of rocks separate from each other, this is called block disintegration.

Question 10.
What is Exfoliation?
Answer:
When the outer layer of the racks fall apart from the main rock due to temperature, the process is called exfoliation.

Question 11.
What does the term ‘diurnal Range’ mean
Answer:
The difference between the daily maximum and minimum temperature is diurnal Range.

Question 12.
What is Solution?
Answer:
The minerals in rocks which dissolve in water leads to the formation of solutions.

Question 13.
Name the two types of mass movements.
Answer:
The two types of mass movements are:
(a) Rapid Mass Movement and
(b) Show Mass movement.

Question 14.
What are the types of Mechanical weathering?
Answer:
The types of Mechanical weathering are
(a) Temperatures
(b) Frost
(c) Crystal growth
(d) Release of pressure and
(c) water

Question 15.
Types of chemical weathering.
Answer:
The types of chemical weathering are:
(a) Carbonation
(b) Solution and
(c) Oxidation

Question 16.
Where does Mechanical weathering occur?
Answer:
Mechanical weathering occurs mainly in the arid climates.

Question 17.
Chemical weathering can be seen in which climates?
Answer:
In humid conditions, one can see chemical weathering.

Write whether the statements are TRUE or FALSE. Correct the incorrect statements.

Question 1.
Soil creep is uncommon in areas with dry climates and gentle slopes.
Answer:
False – It is a common phenomenon in such areas.

Question 2.
Shattering is a type of mechanical weathering
Answer:
True.

Question 3.
Granular weathering occurs in areas of heavy rainfall.
Answer:
True.

Distinguish between:

Question 1.
Mechanical Weathering and Chemical Weathering.
Answer:

Fill the map with the given information and make a legend.
(1) Area affected by a landslide (mudslide) in Maharashtra.
(2) Wadgaon Darya

Give geographical reasons:

Question 1.
Oxidation process occurs in heavy rainfall areas.
Answer:

Question 2.
Chemical weathering occurs in areas of heavy rainfall.
Answer:

Question 3.
Mechanical weathering3 takes place in the cold regions.
Answer:

Question 4.
Rapid mass movements occurs along the steep slopes.
Answer:

Question 5.
Mechanical weathering is seen in areas where the diurnal range of temperature is high.
OR
Change in temperature leads to Mechanical weathering.
Answer:

Question 6.
Water plays an important role in chemical weathering.
Answer:

Question 7.
Frost leads to mechanical weathering.
Answer:

Answer in brief:

Question 1.
What is a mass movement? What are the types of mass movements?
Answer:
The weathered rock materials move along the slopes due to gravity and accumulate near the foothills or the gentler slopes. When the weathered particles move down due to gravity alone, the process is called mass movements.

Types of Mass movements:
(i) Rapid mass movements:

(ii) Slower mass movements:

Question 2.
How does external processes occur?
Answer:

Question 3.
What is exfoliation?
Answer:

Question 4.
Explain the process of oxidation.
Answer:

Explain:

Question 1.
Block Disintegration
Answer:

Question 2.
Carbonation
Answer:

Question 3.
Solution
Answer:

Question 4.
Make a record of few landslides that have occured in India and write about them briefly.
Answer:
Landslide is a rapid mass movement which is caused majorly due to heavy rains, floods, earthquakes etc. The following are some fatal landsides in India.