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Science
Quarter 4 – Week 1: Module 1
How Rocks Turn Into Soil

AIRs - LM
Science
Quarter 4 – Week 1 - Module 1: How Rocks Turn Into Soil
First Edition, 2021

Copyright © 2021
La Union Schools Division
Region I

All rights reserved. No part of this module may be reproduced in any form without
written permission from the copyright owners.

Development Team of the Module

Author: Josephine Castillo Garcia

Editor: SDO La Union, Learning Resource Quality Assurance Team
Illustrator: Ernesto F. Ramos, Jr., P II

Management Team:

Atty. Donato D. Balderas, Jr.

Schools Division Superintendent

Vivian Luz S. Pagatpatan, Ph.D

Assistant Schools Division Superintendent

German E. Flora, Ph.D, CID Chief

Virgilio C. Boado, Ph.D, EPS in Charge of LRMS

Rominel S. Sobremonte, Ed.D, EPS in Charge of Science

Michael Jason D. Morales, PDO II

Claire P. Toluyen, Librarian II

 Target

Hello my dear learners!

In this module, you will learn how rocks turn into soil.

People and animals can live on earth because of the soil. Plants live on soil which
provides them water and minerals. Life on earth would not be possible without soil.
Weathering breaks down rocks into tiny bits and finally into soil. Weathering helps
in forming soil. It takes thousands of years before the rocks finally become soil. The
soil that you seen now in your surroundings was formed from rocks after many
thousands of years. It is a very long and slow process. Soil does not only mean tiny
bits of rocks. It also contains some amount of water, minerals and dead plants and
animals. These things in soil make plants grow.
Could you imagine how life on earth would be without soil?
What would happen if the earth had been covered with hard and big rocks?

https://soilsmatter.wordpress.com/

When you are done with this module, you are expected to attain this learning
competency:
• Describe how rocks turn into soil (S5FE-IVa-1)
 Jumpstart
Before you start, answer the question below to determine how much you know
about the lesson to be tackled.

Think and answer:

1.How are rocks changed into soil?
__________________________________________________________________________________

2. Why does the formation of soil take a long time?

__________________________________________________________________________________

Discover

Weathering is an important process that helps shape the earth’s surface. The
breaking of rocks results in the formation of soil and different landforms. This is
also the reason we have amazing rock formations.
Weathering can either be mechanical/physical or chemical.

Mechanical weathering/Physical weathering occurs when rocks break down into

smaller pieces due to physical forces without changing the mineral compositions of
the rocks. Temperature, water, plants, abrasive agents, and animals contribute to
the mechanical weathering of rocks.

1. Temperature. The sun rays heat up the rocks and rain cools them down. The
exposure to changing temperatures causes stress on the outer surfaces of the
rocks and eventually breaks the rocks into pieces.

2. Water. Water seeps in through some opening or fissures in rocks. When water
freezes, it expands and enlarges these opening. The continued expansion
eventually breaks the rocks into fragments. This process is called frost wedging.

3. Plants. As roots of plants grow, they may enter fractures in rocks and exert
pressure on these spaces. Continues pressure eventually causes the rocks to
break apart. This process is called root wedging.

4. Abrasive agents. Wind, running water, or ice sometimes carries rock fragments
or sand grains that act like sandpaper whenever they strike the surfaces of
rocks. This process of wearing away rocks due to the scouring action of particles
is called abrasion.

5. Animals. Animals that burrow in the ground, such as moles and rabbits, move
deeply buried rocks to the surface where they can be affected by physical and
chemical processes. Buried rock layers may also be exposed and left vulnerable
to water and acid intrusion.

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 tinyurl.com/5ppc4zez tinyurl.com/4mnjhuf9 tinyurl.com/3zbvlnyx

Chemical weathering happens when rocks break down due to reaction with water,
carbon dioxide, oxygen, and organic acids. This process forms new substances
from the minerals of rocks.
1. Oxygen. Oxygen combines with iron to produce iron oxide or rust. This type of
chemical reaction is called oxidation. Rocks with iron-rich minerals are easily
oxidized, thus producing rusty colors on their surfaces. Rust softens the rocks.

2. Carbon dioxide. In addition to oxygen, carbon dioxide also plays a role in

chemical weathering. When carbon dioxide from the atmosphere dissolves in
rainwater, carbonic acid is formed. Precipitation that contains carbonic acid
reacts with the minerals in rocks in a process called carbonation. Carbonic acid
can easily weather marble and limestone.

3. Water. Water weathers rocks either by dissolving their minerals to form a

solution or by combining directly with some minerals to form new minerals. Both
processes occur as a result of chemical reaction called hydration.

4. Plants and animals. A number of plants and animals may create chemical
weathering through the release of acidic compounds. The most common form is
the release of acids by plants which break aluminum- and iron-rich compounds
in soils beneath them. Decaying remains of dead plants and animals in soil may
also form organic acids, which, when dissolved in water, affect surrounding
rocks and soil.

tinyurl.com/qrdt4zsg

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 Explore

Are you ready for some exercises? Remember you can always go back in our
discussion.

Activity 1
Direction: Look for the given words in the puzzle. Encircle each word that you will
find.
R R T U Y I W I N D H B J H J
O F F M E C H A N I C A L G S
C S A D F G H J K P K T G G O
K B T E M P E R A T U R E Q I
S S D D G H J K L T Y T U W L
D W E A T H E R I N G R Q A H
Y S A C H E M I C A L Q Q T G
X Y U P O P I L F G K J U E B
O X Y G E N Q W W Q W Q D R B
P S D F G M I N E R A L S G N

MECHANICAL, CHEMICAL, MINERALS, ROCKS, OXYGEN,

WATER, SOIL, WEATHERING, TEMPERATURE, WIND

Activity 2
Direction: Unscramble the letters to identify the words being described which are
associated with the Earth’s surface.
1. R S O C K
A natural solid material which is usually made up of one or more minerals

2. A L S M I N E R
These are what rocks made up of

3. W T E A H R E N G I
Breaking down of rocks into smaller pieces

4. O I L S
Tiny pieces of rocks which are combined with water and remains of animals and
plants.

5. N I M E C A L C H A
Breaking of rocks into smaller pieces by forces

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Activity 3
Direction: Identify the change happening in each situation. Write PW for physical
weathering and CW for chemical weathering.

1. A boulder of shore is slowly broken apart by the force of water.

2. Earthworm make tunnels in the ground which may lead to the breakdown of
stones and rocks.
3. Some plants release chemicals which loosen the rocks and cause them to break.
4. Water inside the rocks freezes and melts again.
5. The chemical composition of rocks changes when acid is produced by the roots
of some plants.

Deepen

Activity 1

Direction: Read each item carefully and encircle the letter that corresponds to the
correct answer.
1. It is the breaking down of rocks into fragments.
A. Erosion B. Flooding C. Runoff D. Weathering

2. A type of weathering that involves change in the composition of the rock.

A. Chemical B. Mechanical
C. Bothe chemical and mechanical D. None of the above

3. What do you call the process by which human extracts stones from the
mountains for construction purposes?
A. Digging B. Flattening C. Weathering D. Quarrying

4. What will happen to a rock when it is exposed to higher temperature?

A. Contracts B. Evaporates C. Expands D. Sinks

5. An open-pit mine where rocks can be extracted.

A. Landfill B. Open-filled C. Reservoir D. Quarry

Activity 2
Direction: FACT or BLUFF. Read the following situation and write FACT if the
situation describes about weathering and BLUFF if it not.
_____1. In the process of mechanical weathering, the physical characteristic of the
rocks are changed but their chemical compositions remain the same.
_____2. When rocks are worn down by water, wind, or other means, they undergo
weathering.
_____3. Rocks and minerals that are exposed to heat, water, and different gasses in
the air are transformed into new chemical compounds.
_____4. Tree roots can grow into cracks and break rocks apart.
_____5. Weathering is the process that wears away surface materials and moves
them from one location to another.

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Activity 3
Direction: Fill in the box by identifying the kind of weathering taking place in the
following situations.

1. Rust is formed on a rock surface

2. Sudden change in temperature

3. Freezing of water in rock crevices

4. Plants/trees growing in cracks of rocks

5. Force of moving water on rocks

6. Carbon dioxide from the air dissolves in water

7. Water combines with minerals in rocks to form new substances

8. Dissolving of various substances in water which removes minerals in soil

9. Man uses dynamite to break down rocks

10. Quarrying

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 Gauge

Direction: Read each item carefully and choose the letter that corresponds to the
correct answer.

1. What do we call the breaking down of rocks?

A. Erosion B. Landslide C. Tsunami D. Weathering

2. Which of the following can break down rocks?

A. Plants B. Man and animals
C. Extreme temperature D. All of the above

3. Which of the following activities contribute to rock weathering?

A. Mining B. Cutting trees
C. Planting trees D. Landscaping

4. What is the most important effect of weathering on people and animals?

A. Formation of soil B. Formation of clouds
C. Formation of climate D. Formation of minerals

5. You see that some tiny plants are growing on the rocks in the garden. What do
you think will happen after a long period of time? The rocks will _____.
A. grow bigger B. become very hard
C. gather more minerals D. weaken and break apart

6. Weathering breaks down rocks. What is one the useful effect of weathering?
A. Weathering helps in forming fossils.
B. Weathering carries water to streams and oceans.
C. Weathering helps in forming crude oil in rock layers.
D. Weathering helps in forming soil on the surface of the earth.

7. How does temperature break down rocks?

A. Rocks break when they are hammered.
B. Rocks break when there is no more sun.
C. Rocks break when they are heated by the sun.
D. Rocks break when they are heated and then cooled.

8. Which of the following tends to cause physical or mechanical weathering?

A. Animal that burrows in the ground
B. Root of plants growing into the cracks in the rocks
C. Water that seeps into the pores and cracks of rocks
D. All of these

9. The following human activities are caused by physical weathering, EXCEPT.

A. Mining ores
B. Boating and fishing
C. Quarrying of rocks
D. Building roads and tunnels

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10. Plant serves as agents of weathering. Which of the following statements support
this idea?
A. Falling of leaves cause rocks to break.
B. Decaying trunks of plants cause the rocks to break
C. Root of plants that grow in rocks and cause them to break.
D. Branches of plants cause the rocks to break when blown by the winds.

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 Answer Key
Jumpstart
1.Rocks turned into soil through weathering. It can be physical/mechanical weathering and
chemical weathering.
2. Soil formation takes a long time because it follows a process.

Explore
Activity 1

Activity 2
1. ROCKS
2. MINERALS
3. WEATHERING
4. SOIL
5. MECHANICAL

Activity 3
1. PW 2. PW 3. CW 4. PW 5. CW
Deepen
Activity 1
1. D 2. A 3. D 4. C 5. D

Activity 2
1. FACT
2. FACT
3. FACT
4. FACT
5. BLUFF

Activity 3

Gauge
1. D 2. D 3. A 4. A 5. D
6. D 7. D 8. D 9. B 10. C

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References
♦ Sarte, Evelyn T. et. al.2016.Science Beyond Borders 5. Quezon City: Vibal Group,
Inc.
♦ Larisma, Evelyn T & Mariano, Jan Jason M. 2015.The New Science Links. Manila:
Rex Book Store, Inc.
♦ Dela Cruz, Estrellita s. et. al.2000.Science and Health for a Changing
Environment. Quezon City: Vibal Publishing House, Inc.
♦ Curriculum Guide in Science 5
♦ https://soilsmatter.wordpress.com
♦ tinyurl.com/qrdt4zsg
♦ tinyurl.com/5ppc4zez
♦ tinyurl.com/4mnjhuf9
♦ tinyurl.com/3zbvlnyx

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