SCIENCE 8
Protons, Neutrons and Electrons
Quarter 3 Week 5-6
Most Essential Learning Competency:
Determine the number of protons, neutrons and
electrons in an atom
S8MT-IIIe-f-10
Department of Education • Republic of the Philippines
Science– Grade 8
Alternative Delivery Mode
Quarter 3 – Week 5-6: Protons, Neutrons and Electrons
First Edition, 2021
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Published by the Department of Education
Secretary:
Undersecretary:
Assistant Secretary:
Author: Veronica P. Ventura and Reyneth Renan Matta
Editor: Rebecca M. Roxas, EPS-Science
Reviewer: Rogelio A. Yag-at – HT VI
Management and Development Team
School Division Superintendent: Maria Magdalena M. Lim, CESO V
Chief Education Supervisor: Aida H. Rondilla
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CID – LRMDS Librarian II: Lady Hannah C. Gillo
CID – LRMDS PDO II: Albert James P. Macaraeg
HOW TO USE THIS MODULE
Before starting the module, I wa nt yo u to set aside other tasks that will
disturb yo u while enjoying the lessons. Read the simple instructions below
to successfully e njoy the objectives of this kit. Have fun!
1.
2.
3.
4.
5.
Follow carefully all the contents and instructions indica ted in every
page of this module.
Write on yo ur notebook the concepts about the lessons. Writing
enha nces learning that is important to develop and keep in mind.
Perform all the provided activities in the module.
Let your facilitator/guardian assess your a ns wers using the answer
key card.
Analyze conceptually the post-test and apply what yo u ha ve learned.
PARTS OF THE MODULE
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•
•
•
•
•
•
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Expectations – These are what yo u will be able to know after
completing the lessons in the module.
Pre-test – This will measure your prior knowledge and the
concepts to be mastered througho ut the lesson.
Looking Back to Your Lesson - This section will measure what learnings
and skills you understood from the previous lesson.
Brief Introduction – This section will give you an overview of the lesson.
Activities – This is a set of activities that you will perform with a
partner.
Remember – This section summarizes the concepts and
applications of the lessons.
Check your understanding – It will verify how you learned from the
lesson.
Post-test – This will measure how m uc h yo u have learned from the
entire module.
WEEEK 5: PROTONS, NEUTRONS AND ELECTRONS
EXPECTATIONS
In this lesson, you will gain deeper understanding of protons, neutrons and
electrons.
Specifically, this module will help you to:
 Determine the number of protons, neutrons and electrons in an atom;
 Describe the identity of a substance according to its atomic structure; and
 Calculate the atomic number and atomic mass of an atom.
PRE-TEST
Directions: Multiple Choice. Read the statements below then choose the letter of the
BEST answer.
1. The smallest particle of an element is called a/an ________.
a. proton
b. neutron
c. electron
d. atom
2. It is a subatomic particle found within the nucleus and is positively charged.
a. proton
b. neutron
c. electron
d. atom
3. It is a subatomic particle found outside the nucleus and is negatively charged.
a. proton
b. neutron
c. electron
d. atom
4. It is a subatomic particle found within the nucleus and has no charge.
a. proton
b. neutron
c. electron
d. atom
5. The proton, neutron and electron is collectively called _________.
a. subatomic particles
b. subatomic parts
c. subatomic structure
d. subatomic charges
LOOKING BACK TO YOUR LESSON
PARTS OF THE ATOM
The nucleus of an atom contains the protons and neutrons while the electrons are
located outside the nucleus in the electron cloud and are found orbiting the atom in
an orbital.
The structure of an atom
https://otrasteel.blogspot.com/2017/07/31-label-parts-of-atom.ht ml
The charges of protons, neutrons and electrons of an atom varies. Protons are
positively charged and is symbolized as p+ , neutrons have no charge and is
symbolized as no and electrons are negatively charged and is symbolized as e- . This
will be discussed further as we go along the module.
BRIEF INTRODUCTION
The atom is the smallest particle of an eleme nt. Protons, neutrons and electrons
make-up the composition of atoms. Collectively, they are called subatomic particles.
Using the periodic table of elements, the subatomic particles in a given atom can be
computed.
The Periodic Table of Elements
Retrieved at https://pubchem.ncbi.nlm.nih.gov/periodic -table/
PROTONS
To determine the number of protons of an atom, locate the atomic number of a
given element on the periodic table. The atomic number of an element is equal to the
number of protons found in the nucleus of an atom. The number of protons in the
nucleus gives the identity of an element.
No. of Proton = Atomic Number
Take the Helium element as an example, the atomic number of Helium (He) is 2.
Therefore, the number of protons found in the nucleus of Helium is also 2.
Helium
Retrieved from Encyclopædia Britannica, Inc. All rights reserved.
ELECTRONS
The number of electrons is determined using the atomic number. The number
of electrons in an atom is equal to the atomic number. Because the atom is neutral in
charge, the positive and negative charges are equal to one another.
No. of Electron = Atomic Number
Using Helium as an example, the atomic number of Helium is 2, making the
number of electrons of Helium 2 as well.
NEUTRONS
The number of neutrons is calculated by subtracting the number of protons
found in the nucleus from the mass number. The mass number is usually located
below the element symbol in the periodic table of elements.
No. of Neutrons = Mass number – No. of protons
or
No. of Neutrons = Mass number – Atomic number
ACTIVITIES
Activity 1. Complete Me!
Directions. Using the Periodic Table of Elements, determine the number of protons,
neutrons and electrons in an atom to complete the table below.
Element
Element Atomic
Mass
No. of
No. of
No. of
Symbol Number Number Protons Neutrons Electrons
Neon
Ne
Phosphorus
P
Sodium
Na
Pb
Ytrium
Argon
20
8
16
15
31
(no)
8
8
82
207
(e-)
15
24
Y
Copper
Boron
10
(p+)
13
11
50
39
35
29
82
89
29
B
5
11
5
5
C
6
12
6
6
18
40
22
Activity 2: Locate Me!
A. Table Completion.
Directions. Complete the table below.
Sub-atomic
Particle
Symbol
Charge
Location in the
Atom
Proton
Neutron
Electron
B. Fill in the blanks.
Directions. Use your knowledge of the periodic table of elements to answer the
following:
1. Give the number of protons in one atom of:
Lithium
Krypton
Iron
2. Give the number of neutrons in one atom of:
Vanadium
Silicon
______
3. Give the number of electrons in one atom of:
Mercury
Arsenic
REMEMBER
1. The ATOMIC NUMBER is equal to the number of PROTONS and ELECTRONS
in an atom. You can use the acronym A.P.E. as a guide to remember the
concept.
ATOMIC NUMBER = PROTON = ELECTRON
2. The number of NEUTRONS is computed by subtracting the number of
PROTONS from the MASS NUMBER.
NEUTRONS = MASS NUMBER - PROTONS
CHECK YOUR UNDERSTANDING
Directions: Fill in the blanks with the appropriate term to complete the statement below.
Choose your answers from the word box.
4. The three particles of the atom and their respective charges are:
a.
b.
c.
5. The atomic number tells you the number of
in
one atom of an element. It also tells you the number of
in a
neutral atom of that element. The atomic number gives the “identity “of an element
as well as its location on the Periodic Table. No two different elements will have the
atomic number.
WORD BOX:
Same
Protons
Electrons
Positive
No Charge
Protons
Negative
Electrons
Neutrons
POST TEST
1. An atom of an element is electrically neutral because the
a. Number of protons equals the number of electrons
b. Number of protons equals the number of neutrons
c. Number of neutrons equals the number of electrons
d. Number of atoms equals the number of electrons
2. The element Lithium has an atomic number of 3. It also has ____ number of protons:
a. 1
b. 2
c. 3
d. 4
3. There are the same number of these two particles in an atom
a. protons and neutrons
b. protons and electrons
c. neutrons and electrons
REFERENCES
Nerd, Alicia. 2017. Label the Parts of an Atom.
Retrieved at https://otrasteel.blogspot.com/2017/07/31-label-parts-ofatom.html on February 15, 2021
Encyclopedia Brittanica Inc. Helium. Retrieved at
https://www.google.com/imgres?imgurl=https%3A%2F%2Fcdn.britannica.com%2
F98%2F22398-050-BDC6E4E4%2Felement-helium-symbol-square-propertiessomeperiodic.jpg&imgrefurl=https%3A%2F%2Fwww.britannica.com%2Fscience%2Fh
elium-chemical-element&tbnid=7MVeOkwNblGRoM&vet=12ahUKEwiunYPB9juAhVE6JQKHUlzC_wQMygIegUIARDhAQ..i&docid=WYJ0gcgO7QcJCM&w=16
00&h=1068&q=element&ved=2ahUKEwiunYPB9juAhVE6JQKHUlzC_wQMygIegUIARDhAQ
Youngker, Andrew. 2018. How to Calculate Subatomic Particles
Retrieved at https://sciencing.com/calculate-subatomic-particles-8221603.html on
February 14, 2021
PubMed. National Library of Medicine. National Center for Biotechnology Information.
Periodic
Table
of
Elements.
Retrieved
at
https://pubchem.ncbi.nlm.nih.gov/periodic-table/ on February 14, 2021.
Atomic
Structure
Worksheet.
Atomic
Structure
Packet.
Retrieved
at
https://www.washoeschools.net/cms/lib/NV01912265/Centricity/Domain/1130/Ato
mic%20Structure%20Packet.doc