DESCRIBE THE DIFFERENT

CHARGING PROCESSES
for SCIENCE Grade 7
Quarter 3 / Week 8

NegOr_Q3_Science 7_SLK Week 8_v2

NegOr_Q3_Science 7_SLK Week 8_v2 1
 FOREWORD

In this self- learning kit, you will learn about the different types of
charges and perform activities that will demonstrate how objects can be
charged in different ways.

This self-learning kit will also enhance your knowledge on the

importance of grounding and the use of lightning rods. At the end of the
module, you will do an activity that will introduce you to simple electric
circuits. So have fun in answering the questions in the different activities
provided in this self-learning kit.

NegOr_Q3_Science 7_SLK Week 8_v2

2
 OBJECTIVES
K: Describe the different charging processes.
S: Illustrate Conduction and Induction as means of electrification.
A: Make predictions and observations on the interaction of charged
bodies.

LEARNING COMPETENCY
Describe the different types of charging processes.
(S7LT -IIIj – 13)

I. WHAT HAPPENED

A. Pre-Test
WORDSTORM
Directions: Some letters of the following words are missing in each set. Supply
the missing letters based on the brief descriptions.
1. C_N_U_ _IO_ transfer of charge through direct contact.

2. _ND_ _ T _ ON transfer of charge without physical contact.

3. F_ IC _ IO _ transfer of charge by rubbing.

4. G _ OU _ _ I _ G transfer of charge from higher point to the

subsurface of Earth.
5. _ L _ CT _ _ N negatively charged particle.

6. P _ OTO _ positively charged particle.

7. G _ ND _ _ T _ R type of material that allows charges to flow.

8. _ NS _ L _ _ OR type of material that does not readily allow the flow

of charge.
9. NUT _ _ L material where the number of positive and negative
charges is the same.
10. _EU_R_N neutrally charged particles inside the nucleus of an
atom.

NegOr_Q3_Science 7_SLK Week 8_v2

3
II. WHAT I NEED TO KNOW
DISCUSSION
Around 600 BC, ancient Greeks discovered a piece of amber. Amber is
a hard translucent resin. Ancient Greeks observed that amber attracted
other materials after it was rubbed with fur. In fact, the Greek word electron,
where the term “electricity” was coined, means “amber.”

When you use your comb and place it near bits of paper, you will
observe the amber effect, a phenomenon that was documented by the
ancient Greeks. The reason for this observation remained unknown until
Benjamin Franklin conducted a series of experiments that revealed that
matter possessed a property independent of its mass. This property is now
called the electric charge. An object with an electric charge may
experience a force when it is close to another object.

It was discovered later those materials exhibit two types of charge,

namely, positive charge and negative charge. When rubbed against a
certain material, a triboelectric effect is produced, wherein materials
become charged. The presence of these two charges may depend on the
properties of the material. For example, when plastic and hard rubber are
rubbed, they become negatively charge. Likewise, when glass and wool are
rubbed, they become positively charged.
The fundamental law of charge states that “like charges repel each
other, and unlike charges attract each other.” The force of attraction and
repulsion is equal but opposite. This force is dependent on the distance
between the two objects. The force between the charges weakens as the
distance increases.

Figure 1 Figure 2

NegOr_Q3_Science 7_SLK Week 8_v2

4
The electrostatic force of attraction and repulsion between two objects is
dependent on the number of charges and the distance between them.

Recall that an atom consists of a nucleus that contains positively

charged protons and neutrally charged neutrons. The force between these
protons and neutrons cannot be weakened by ordinary means. It would
require some form of high energy to disturb the nucleus and subsequently
remove its protons. Likewise, the vast space around the nucleus is where
electrons are found. They are negatively charged and are weakly bound to
the atom. Electrons are often removed from and added to an atom by
chemical reactions.

The number of electrons that

surrounds the nucleus determines
whether an atom is electrically charged
or electrically neutral. If an atom contains
equal numbers of protons and electrons,
the atom is described as electrically
neutral. Otherwise, the atom is electrically
charged if it has an unequal number of
protons and electrons

Introduction
All objects are electrically neutral. Because of their interactions with other
objects, they become charged, either positively or negatively. In this
activity, you will investigate the charging process and the factors that
may affect it.

Activity 1

Objective: To demonstrate the force of repulsion between two bodies of the

same charge.

Materials: Two inflated balloons, nylon strings, PVC pipe, plastic sheet

Procedure:
1. Keep the room temperature low to achieve the conditions necessary
for a charge to build up. You can conduct this activity in an air-
conditioned room.
2. Using the nylon string, hang the two balloons from the ceiling, keeping
a distance of about 3 cm between them.
3. Charge the PVC pipe by rubbing it with the plastic sheet. Then place it
in between the two balloons. Observe what happens.

NegOr_Q3_Science 7_SLK Week 8_v2

5
Guide Questions: (Write your answer in your notebook.)

1. What happened when the charged PVC pipe was placed in between
the balloons?
2. How did the room temperature affect the build-up of electric charge?
3. What have you learned in this activity about how materials become
charged?

THE CHARGING PROCESSES

1. Charging by Friction
In the previous discussion, you have learned that the different materials
possess unique electrical properties. Some materials allow electrons to flow
freely, whereas others do not. When you rub one material against another,
one material may be able to gain electrons more than the other.
To understand the process of charging, consider a rubber rod rubbed
against animal fur. During rubbing, the atoms of the rubber are in proximity
with the atoms of the animal fur. Of the two materials, the rubber has the
tendency to gain electrons. This means that it will take electrons from the
atoms of animal fur. When rubbing has ceased the two objects have now
become charged.
This process is called rubbing or charging by friction. The number of
protons in each object remains the same, but the number of electrons
changes. The animal fur, which losses electrons, becomes positively charged
and the rubber rod, which gains electrons, becomes negatively charged.

NegOr_Q3_Science 7_SLK Week 8_v2

6
2. Charging by Induction

The figure above shows two neutral insulated metal spheres (A and B)
that are initially touching each other.
The spheres are insulated so that any charge acquired by them cannot travel
to the ground. Because both spheres are conductors, electrons can freely
move from sphere A to sphere B, and vice versa. Suppose that a negatively
charged balloon is placed near sphere A. The electrons in sphere A repelled
by the balloon and eventually transferred to sphere B, leaving sphere A
positively charged. Spheres A and B are charged by induction.

3. Charging by conduction
Unlike induction, the process of conduction requires physical contact
between two materials. This why it is also called “charging by contact “.
Suppose a negatively charged rod is in contact with the knob of an
electroscope, as shown below.

NegOr_Q3_Science 7_SLK Week 8_v2

7
 As you learned in the previous sections, charges will move from one
object another due to attractive or repulsive forces among them. The leaves
of the electroscope had spread apart due to the presence of a positively
charge.
As a result, the electroscope becomes charged. This method of
charging a neutral body by a charged body is called conduction. The
deflection of the leaves of the electroscope can also be observed if the
electroscope is charged negatively.

III. WHAT I HAVE LEARNED

EVALUATION/POST TEST
True or False
DIRECTIONS: Write True if the statement is correct. Write False if the statement
is incorrect. Write your answer on your answer sheet.
______1. An electric charge can be classified as positive or negative.
______2. Like charges attract, and unlike charges repel.
______3. The SI unit of charge is the coulomb.
______4. Only the protons are transferred from one object to another when
objects interact.
______5. The force of repulsion increases with increasing distance.
______6. Grounding causes the charge to flow to the ground.
______7. Electric charge is a physical property of matter that causes a
material to experience a force when it is close to another matter.
______8. When positive rod is brought close to another positive material, the
two objects will attract.
______9. When a positive rod is brought close to a negative material, the two
objects repel.
_____10. When a positive charge is placed in the surface of the conductor, it
will move as far away as possible from the neutrally charge
conductor.

NegOr_Q3_Science 7_SLK Week 8_v2

8
REFERENCES

Ling, Samuel J., Jeff Sanny Loyola, and William Moebs. 2016. University Physics.
Vol. 1. OpenStax. https://openstax.org/details/books/university-physics-
volume-1 in your citation.

PAUL A. TIPLER, GENE MOSCA. 2008. PHYSICS FOR SCIENTIST AND ENGINEERS.
Susan Finnemore Brennan.

Paul Peter Urone, Roger Hinrichs. 2012. OpenStax. June 21.

https://openstax.org/books/college-physics/pages/20-1-current.
Young, Hugh D., and Roger A. Freedman. 2012. Sears and Zemansky's
university physics : with modern physics. -- 13th ed. 13th. Edited by
Nancy Whilton. Jim Smith.

NegOr_Q3_Science 7_SLK Week 8_v2

9
 DEPARTMENT OF EDUCATION
SCHOOLS DIVISION OF NEGROS ORIENTAL

SENEN PRISCILLO P. PAULIN, CESO V

Schools Division Superintendent

JOELYZA M. ARCILLA EdD

OIC - Assistant Schools Division Superintendent

MARCELO K. PALISPIS EdD JD

OIC - Assistant Schools Division Superintendent

NILITA L. RAGAY EdD

OIC - Assistant Schools Division Superintendent/CID Chief

ROSELA R. ABIERA
Education Program Supervisor – (LRMDS)

ARNOLD R. JUNGCO
PSDS– Division Science Coordinator

MARICEL S. RASID
Librarian II (LRMDS)

ELMAR L. CABRERA
PDO II (LRMDS)

VICENTE B. MONGCOPA
Writer

ZIPPORAH S. MONGCOPA
Illustrator

STEPHEN C. BALDADO
HELBERT P. OJARIO
Lay-out Artists
_____________________________
ALPHA QA TEAM
ZENAIDA A. ACADEMIA
ADELINE FE D. DIMAANO
FLORENTINA P. PASAJINGUE
BETA QA TEAM
ZENAIDA A. ACADEMIA
ALLAN Z. ALBERTO
EUFRATES G. ANSOK, JR.
ROWENA R. DINOKOT
LESTER C. PABALINAS

DISCLAIMER
The information, activities and assessments used in this material are designed to provide accessible
learning modality to the teachers and learners of the Division of Negros Oriental. The contents of this module
are carefully researched, chosen, and evaluated to comply with the set learning competencies. The writers
and evaluator were clearly instructed to give credits to information and illustrations used to substantiate this
material. All content is subject to copyright and may not be reproduced in any form without expressed written
consent from the division.

NegOr_Q3_Science 7_SLK Week 8_v2

10
SYNOPSIS
10. FALSE
The interaction between charges is 9. FALSE

like magnets. Like poles repel and unlike

8. FALSE
7. TRUE

poles attract each other. One of the

6. TRUE
5. FALSE
applications of interaction of charges can 4. TRUE
3. TRUE
be manifested when the hair in your hand 2. FALSE
1. TRUE
will stand when you switch on you TV set. POSTEST:
3. Answer may vary

Your knowledge in the interaction of

2. Answer may vary
1. Answer may vary
charges will lead you to the understanding
ANSWER TO GUIDE QUESTIONS:
10. NEUTRON
of electrostatics. 9. NEUTRAL
8. INSULATOR
7. CONDUCTOR
6. PROTON
5. ELECTRON
4. GROUNDING
3. FRICTION
2. INDUCTION
1. CONDUCTION

Pre-Test: WORDSTORM

ANSWER KEY:

ABOUT THE AUTHOR

Writer: Vicente B. Mongcopa holds Bachelor’s

Degree in Physics from Foundation University Last
March 1985 at Dumaguete City. He finished his
master’s degree in Educational Management at
Southern Philippines Foundation Last 2016 at Lahug,
Cebu City. Has been a facilitator and a writer to the
different In- Service Trainings and Division Seminars
and Workshops in Science. Presently a Master
Teacher I at Negros Oriental High School teaching
Physics.

Lay-Out Artist/Illustrator: Zipporah S. Mongcopa

She is currently a Grade 12 student from Silliman University
Senior High School, taking up STEAM as her strand. She is a
consistent honor student from her elementary years and
even in her junior high years.

NegOr_Q3_Science 7_SLK Week 8_v2

11