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1. General
Chemistry 1
Quarter 2 – Module 2:
Electronic Structure of Atoms:
Electron Configuration
11

2. s
General Chemistry I – Grade 11
Self-Learning Module (SLM)
Quarter 2 – Module 2: Electronic Structure of Atoms: Electron Configuration
First Edition, 2020
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3. 11
General
Chemistry I
Quarter 2 – Module 2:
Electronic Structure of Atoms:
Electron Configuration

4. Introductory Message
For the facilitator:
Welcome to the General Chemistry I Self-Learning Module (SLM) on Electronic
Structure of Atoms: Electron Configuration!
This module was collaboratively designed, developed and reviewed by educators
both from public and private institutions to assist you, the teacher or facilitator in
helping the learners meet the standards set by the K to 12 Curriculum while
overcoming their personal, social, and economic constraints in schooling.
This learning resource hopes to engage the learners into guided and independent
learning activities at their own pace and time. Furthermore, this also aims to help
learners acquire the needed 21st century skills while taking into consideration their
needs and circumstances.
In addition to the material in the main text, you will also see this box in the body of
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You also need to keep track of the learners' progress while allowing them to manage
their own learning. Furthermore, you are expected to encourage and assist the
learners as they do the tasks included in the module.
Notes to the Teacher
This contains helpful tips or strategies that
will help you in guiding the learners.
2

5. For the learner:
Welcome to the General Chemistry I Self-Learning Module (SLM) on Electronic
Structure of Atoms: Electron Configuration!
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What’s In This is a brief drill or review to help you link
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What’s New In this portion, the new lesson will be
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What is It This section provides a brief discussion of
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What’s More This comprises activities for independent
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answers to the exercises using the Answer
Key at the end of the module.
What I Have Learned This includes questions or blank
sentence/paragraph to be filled in to process
what you learned from the lesson.
What I Can Do This section provides an activity which will
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3

6. Assessment This is a task which aims to evaluate your
level of mastery in achieving the learning
competency.
Additional Activities In this portion, another activity will be given
to you to enrich your knowledge or skill of
the lesson learned. This also tends retention
of learned concepts.
Answer Key This contains answers to all activities in the
module.
At the end of this module you will also find:
The following are some reminders in using this module:
1. Use the module with care. Do not put unnecessary mark/s on any part of
the module. Use a separate sheet of paper in answering the exercises.
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included in the module.
3. Read the instruction carefully before doing each task.
4. Observe honesty and integrity in doing the tasks and checking your answers.
5. Finish the task at hand before proceeding to the next.
6. Return this module to your teacher/facilitator once you are through with it.
If you encounter any difficulty in answering the tasks in this module, do not
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We hope that through this material, you will experience meaningful learning and
gain deep understanding of the relevant competencies. You can do it!
References This is a list of all sources used in developing
this module.
4

7. What I Need to Know
This module was designed and written with you in mind. It is here to help you
master the Electron Configuration: Magnetic Property of the Atom. The scope of this
module permits it to be used in many different learning situations. The language
used recognizes the diverse vocabulary level of students. The lessons are arranged
to follow the standard sequence of the course. But the order in which you read them
can be changed to correspond with the textbook you are now using.
The module is about:
 Lesson 1 – Electronic Structure of Atoms: Electron Configuration
After going through this module, you are expected to:
1. write the electronic configuration of elements;
2. illustrate the electron distribution using orbital diagrams; and
3. determine the magnetic property of an atom based on its electronic
configuration.
5

8. What I Know
Choose the letter of the best answer. Write the chosen letter on a separate sheet of
paper.
1. What is the maximum number of electrons can a p-orbital hold?
a. 2
b. 6
c. 10
d. 14
2. Which of the following contains an unpaired electron?
a. Br
b. Ca
c. He
d. K
3. Which of the following elements has the least number of orbitals?
a. N
b. S
c. I
d. Fr
4. How many electrons does the element Silver has?
a. 10
b. 47
c. 107
d. 868
5. How many electrons can the 1st energy level hold?
a. 1
b. 2
c. 8
d. 0
6. An orbital can hold a maximum of how many electrons?
a. 2
b. 6
c. 10
d. 14
7. How many orbitals are in the 4p subshell?
a. 1
b. 3
c. 7
d. 8
8. What does the up and down arrows in orbital diagram represent?
a. Protons and electrons
b. Electron’s magnetic field
c. Electrons with opposite spins
d. Electrons with opposite
charges
9. Which atomic subshell will follow 6s?
a. 7s
b. 6p
c. 5d
d. 4f
10.When can we say that an atom is in ground state?
a. If it generates magnetic field
b. If it is either paramagnetic or diamagnetic
c. If electrons in an atom have the lowest possible energies
d. If electrons are jumping from one energy level to another
6

9. Lesson
1
Electronic Structure of
Atoms: Electron
Configuration
Electrons in atoms are arranged in a certain way which is referred to as
electronic configuration. This electronic structure tells us of the number of
electrons in the atom as well as their distribution around the nucleus and their
energies. Electron configuration summarizes the distribution of electrons around
the atomic orbitals.
What’s In
Directions: Write all the words that you can associate with quantum numbers
then select two (2) words from your constructed mind map and describe or explain
these words in the given space below.
D
• g _____
• h_____
E
• i _____
• j______
F
• k_____
• l_____
A
• a ____
• b____
B
• c ____
• d ____
C
• e _____
• f _____
1. __________________________________________________________________
2. __________________________________________________________________
7
QUANTUM
NUMBERS

10. Notes to the Teacher
This module is composed of different activities about the
magnetic property of the atom based on its electronic
configuration. Utilization of different resources is suggested.
8

11. What’s New
Directions: Hidden in the puzzle are words associated with atomic structure. Find
and encircle the words listed below.
Atomic number
Orbital
Thomson
Democritus
Positive
Nucleus
Subatomic
Negative
Aristotle
Dalton
Atoms
Neutrons
Electrons
Energy levels
Electron cloud
Ion
Element
Bohr
Isotope
Rutherford
Plum pudding
Atomic mass
Protons
9

12. What is It
Electron configurations is the electronic structure of an atom in its ground
state as a listing of orbitals occupied by the electrons. It provides insight into the
chemical behavior of elements by helping determine the valence electrons of an
atom. It allows for the elements to be classified into different orbitals or blocks (such
as the s-block, p-block, d-block, and f-block elements). The four quantum numbers
n, l, ml, and ms are also very useful in determining the location of an electron in an
orbital.
Atomic Orbitals
An atomic orbital can be used to find the probability of location an electron
in a specific region around the nucleus. There are four types of orbitals, s, p, d, and
f. s-orbital is a spherical region of space with high electron density and can hold up
to maximum of 2 electrons. p-orbital is a dumbbell-shaped region of space with
high electron density and can hold a maximum of 6 electrons. d-orbital is a four-
lobed shaped region that can hold up to a maximum of 10 electrons. f-orbital is a
multilobed region of space with high electron density and can hold a maximum of
14 electrons.
The quantum mechanical model of an atom uses three quantum numbers to
describe an orbital: principal quantum number, azimuthal quantum number, and
magnetic quantum number. The collection of orbitals with the same value of n is
called an electron shell. All the orbitals that have n=2 are said to be in the second
shell. The orbitals that have the same n and ℓ values is called a subshell. Each
subshell is designated by a number (the energy level) and a letter (s, p, d, f that
refers to the value of ℓ). Example, the orbitals that have the values of n=2 and ℓ =0
are called 2s orbitals and are in the 2s subshell.
Figure 1.Order of filling up of electrons by energy levels of an atom
Each box represents
one orbital
Each row represents
one shell
Each cluster of boxes
represents one subshell
10

13. Orbital Diagrams
Orbital diagrams are used to represent how electrons are arranged in
an orbital. Orbitals are represented by boxes and electrons are represented
by arrows. Each block can hold a maximum of two (2) electrons of opposing
spins. Take for example the element Hydrogen with electron configuration
1s1 can be represented as:
or
Orbital diagrams can help determine the electron configuration of an
element as electron configuration is simply the arrangement of electrons in
the shells. Filling of atomic orbitals follows a set of rules:
1. Aufbau Principle – the term “aufbau” originates from German word
Aufbauen which means “to build”. In essence, when writing electron
configurations, the lower energy levels are filled up first before the
higher energy levels. According to this principle, electrons are filled
following this order: 1s, 2s, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d,
6p, 7s, 5f, 6d, 7p
Figure 2. Filling up of electrons according to Aufbau Principle
2. Pauli’s Exclusion Principle - in 1925, an Austrian physicist named
Wolfgang Pauli discovered how electron spin works and established
the Pauli’s Exclusion Principle. This principle states at no two
electrons can have the same set of four quantum numbers and an
orbital can only hold a maximum of two electrons, which are of
opposing spins. Thus, writing the orbital diagram element of Lithium,
with an atomic number of 3, must be:
And NOT
3. Hund’s Rule – every orbital in a subshell is singly occupied with one
electron before any one orbital is doubly occupied, and all electrons in
11

14. singly occupied orbitals have the same spin. For example, the element
Carbon which 6 electrons (remember, atomic number = number of
electrons), the orbital diagram should look like:
Example:
Element # of
electrons
Orbital Diagram
Beryllium 4
Nitrogen 7
Electron Configuration
Electron configuration summarizes the distribution of electrons
around the atomic orbitals. Electron configuration explains an element’s
chemical behavior by helping determine the valence electrons of an atom. It
is often found in most periodic tables and follows a standard notation. For
example, the electron configuration of Fluorine (9) is 1s22s22p5 as it is
located on the 2nd energy level and 5th element on the p-block. It is also
interesting to note that valence shell (2) in this example corresponds to the
period where to find the element and the valence electron (7) corresponds to
the group (+10) / Family (A elements only) of the said element.
12

15. Figure 3. Periodic Table of Elements
In writing the electron configuration, it must be noted that the total
number of electrons that can be accommodated in a shell is based on the
principal quantum number (n). The subshells, on the other hand, are
determined by the azimuthal quantum number (ℓ). The s, p, d, f subshells
can accommodate up to 2, 6, 10, 14 respectively. If you have observed, the
subshells are the same number of the elements on each block per energy
level. For example, the element Sodium (Na) has 11 electrons and is located
on the 3rd energy level on the s block in the first row, which means that its
electron configuration is 1s22s22p63s1.
Electron Spin
The electronic structure of an atom can be described in terms of
orbitals. So far, we have learned how quantum mechanics can be used to
s
b
l
o
c
k
d block
p
block
f block
Figure 4. Electron configuration displays the identity of an atom
13

16. define an atom. In addition, the nature of orbitals and their relative energies
as well as how the electrons populate the available orbitals must be
considered. But how do electrons really occupy the available orbitals? To
answer this question, we must consider the additional property of the
electron.
In the previous lesson, we have learned about the spin quantum
number which describes the direction in which the electron is spinning
within an orbital.
It is essential to note that understanding how the electron behaves
gives way to comprehend the electronic structure of atoms. It is important to
remember that the electron spin is represented by the possible values of the
spin quantum number.
The spinning of electrons generates magnetic spins whose directions
depends on the direction of the spin, making it an electric charge in motion.
Paramagnetism is the attraction of materials to a magnetic field; it refers to
the magnetic state of an atom with one or more unpaired electrons.
Diamagnetism is the repulsion of materials by a magnetic field; these
materials are characterized by paired electrons. The reason it repels a
magnetic field is because when orbitals are filled with paired electrons, they
are spinning in opposite directions, as stated in Pauli’s Exclusion Principle,
and as a result, the magnetic field of electrons gets cancelled out, thus there
is no magnetic moment.
To determine whether a substance is paramagnetic or diamagnetic,
the electron configuration must be examined. If it has unpaired electrons, it
is paramagnetic. If all electrons are paired, the substance is diamagnetic.
Example:
Element Orbital diagram Paramagnetic
or diamagnetic
# of
unpaired
electrons
He Diamagnetic 0
Na Paramagnetic 1
14

17. What’s More
Excellent work! Now that you have already learned about electron configuration,
you can easily do the next activity.
Activity 1: Orbital Diagram
Objective: Illustrate the electron distribution using orbital diagrams
Direction: Draw the orbital diagram of the following elements
Element # of
electrons
Orbital Diagram
Beryllium 4
Boron
Nitrogen
Fluorine
Neon
Sodium
Activity 2: Paramagnetic or Diamagnetic
Directions: Fill out the information needed for the following elements:
Element # of
electrons
Electronic
configuration
Orbital
diagram
Paramagnetic
or
Diamagnetic
1. Chlorine
2. Calcium
3. Iron
4. Argon
15

18. What I Have Learned
Summarize what you have learned from the very start by answering the questions
below.
1. What the four types of atomic orbital? Describe each.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
_________________________________________________________________________.
2. How is the electron configuration written?
__________________________________________________________________________
__________________________________________________________________________
_________________________________________________________________________.
3. How does the atom generate a magnetic field?
__________________________________________________________________________
_________________________________________________________________________.
4. What needs to be considered when making an orbital diagram of an element?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
16

19. What I Can Do
Job well done! You are close completing your work. Now is the time you apply
what you have learned in this module.
Apartment Analogy
Imagine you are the landlord of a very strange apartment building. Your job
is to fill the apartments in the most specific and efficient way. The rules you have
to follow in filling this apartment is the same as the rules followed by the electrons
when filling the orbitals. Now how will you fill your apartment up? Describe the
method of filling up the apartment using the rules in filling up the orbitals.
Rules in Filling Up the Orbitals Rules in Filling Up the Apartment
Aufbau Principle:
Hund’s Rule
Pauli’s Exclusion Principle:
17

20. Assessment
Multiple Choice. Choose the letter of the best answer. Write the chosen letter on a
separate sheet of paper.
1. Which of the following statements about the s, p, and d orbitals are true?
a. 3p orbital has the same energy with a 3s orbital
b. only s orbital can have a maximum of 6 electrons
c. s, p, and d orbitals are of the same shape but of different energy levels
d. a p orbital has a higher energy than the s orbital of the same principal
quantum number
2. What element is element X if it has the following electron
configuration and orbital diagram?
a. Aluminum
b. Boron
c. Neon
d. Phosphorus
3. How many electrons can the p-orbital hold?
a. 2
b. 6
c. 10
d. 14
4. Which is the correct way of writing the orbital diagram of the element
Nitrogen?
a.
b.
c.
d.
18

21. 5. Which of the following elements can generate electromagnetic field?
a. Br
b. Ca
c. He
d. K
6. Which of the following is the correct sequence of increasing energy level?
a. 2s, 3p, 3d, 4s
b. 4s, 3d, 3p, 4p
c. 3s, 3p, 4s, 5f
d. 6s, 4f, 5d, 6p
7. What type of orbital must an electron with principal quantum number n=2
occupy?
a. cone-shaped orbital
b. either an s or p orbital
c. low density region of space
d. the orbital closest to the nucleus
8. Which element is diamagnetic?
a. Antimony
b. Barium
c. Sodium
d. Polonium
9. The total number of unpaired electrons of Cobalt (Co – 27) is ________.
a. 2
b. 3
c. 4
d. 5
10.In a subshell of an atom, the total number of allowed orbitals is equal to:
a. ℓ
b. ℓ + 1
c. ℓ + 2
d. 2ℓ + 1
19

22. Additional Activities
Congratulations! You’ve come this far. I know you’ve learned a lot in Electronic
Structure: Electron Configuration. Do additional reading on the significance of spin
quantum number (ms).
Suppose that the spin quantum number could have three allowed values instead of
two. How would this affect the number of elements in the first four rows of the
periodic table?
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20

23. Rubric for Evaluation:
21

24. Answer Key
What’s More
Activity 1:
Activity 2:
What
I
Know:
1.b
2.
d
3.
a
4.
b
5.
b
6.
a
7.
b
8.
c
9.
d
10.
c
Assessment:
1.
d
2.
a
3.
b
4.
c
5.
d
6.
d
7.
b
8.
b
9.
b
10.
d
22

25. References
Pettrucci, Ralph H. General Chemistry: Principles and Modern Applications.
9th. Upper Saddle River: Pearson Prentice Hall, 2007
Sherman, Alan, Sharon J. Sherman, and Leonard Russikoff. Basic Concepts of
Chemistry Fifth Edition. Boston, MA: Houghton Mifflin Company, 1992.
Print. Provided by:
https://chem.libretexts.org/Courses/Mount_Royal_University/Chem_1201
/Unit_2._Periodic_Properties_of_the_Elements/2.07%3A_Magnetic_Propertie
s_of_Atoms_and_Ions
Electron configuration. Provided by: Wikipedia. Located
at: http://en.wikipedia.org/wiki/Electron_configuration. License: CC BY-SA:
Attribution-ShareAlike
Free High School Science Texts Project, The Atom: Energy Quantisation and
Electron Configuration. August 22, 2020. Provided by: OpenStax
CNX. Located at: http://cnx.org/content/m39967/latest/. License: CC BY:
Attribution
Aufbau principle. Provided by: Wikipedia. Located
at: http://en.wikipedia.org/wiki/Aufbau_principle. License: CC BY-SA:
Attribution-ShareAlike
Pauli Exclusion Principle. Provided by: Wikipedia. Located
at: http://en.wikipedia.org/wiki/Pauli%20Exclusion%20Principle. License:
CC BY-SA: Attribution-ShareAlike
Hund's rules. Provided by: Wikipedia. Located
at: http://en.wikipedia.org/wiki/Hund's_rules. License: CC BY-SA:
Attribution-ShareAlike
High School Chemistry/Orbital Configurations. Provided by: Wikibooks. Located
at: http://en.wikibooks.org/wiki/High_School_Chemistry/Orbital_Configura
tions. License: CC BY-SA: Attribution-ShareAlike
Diamagnetic. Provided by: Wikipedia. Located
at: http://en.wikipedia.org/wiki/Diamagnetic. License: CC BY-SA:
Attribution-ShareAlike
Paramagnetic. Provided by: Wikipedia. Located
at: http://en.wikipedia.org/wiki/Paramagnetic. License: CC BY-SA:
Attribution-ShareAlike
Periodic Table of Elements. Provided by: viosplatter. Located at:
https://search.creativecommons.org/photos/4a469070-109d-4ff0-ba36-
910f038097ff. License:
23

26. EDITOR’S NOTE
This Self-Learning Module (SLM) was developed by DepEd
SOCCSKSARGEN with the primary objective of preparing for and addressing
the new normal. Contents of this module were based on DepEd’s Most Essential
Competencies (MELC). This is a supplementary material to be used by all
learners of SOCCSKSARGEN Region in all public schools beginning SY 2020-
2021. The process of LR development was observed in the production of this
module. This is Version 1.0. We highly encourage feedback, comments, and
recommendations.
For inquiries or feedback, please write or call:
Department of Education – SOCCSKSARGEN
Learning Resource Management System (LRMS)
Regional Center, Brgy. Carpenter Hill, City of Koronadal
Telefax No.: (083) 228 8825 / (083) 228 1893
Email Address: region12@deped.gov.ph