This document discusses electron configuration and orbital diagrams. It defines electron configuration as the arrangement of electrons in atomic orbitals, following standard notation. Orbital diagrams visually represent electron arrangement using labeled circles for orbitals. The document explains the Aufbau principle, Pauli exclusion principle, and Hund's rule for determining electron configuration. It provides examples of writing configurations and drawing diagrams for various elements like Li, Na, N, Al, Cl, Fe, O, and Ca. The document emphasizes that rules are important in electron configurations as they are in other areas of life.

1. ELECTRON
CONFIGURATION

2. Objectives:
a) Define electron configuration.
b) Write electron configuration and draw
the orbital diagram of different elements.
c) Appreciate the importance of having
rules in writing the electron
configuration of elements and also in
real life situation.

3. Recall

4. Engage
Community vs. Atom
barangay energy level
Purok sublevel
house atomic orbital

6. To summarize

7. What is electron configuration?
 The electron configuration of an element
describes how electrons are distributed in
its atomic orbitals. Electron configurations
of atoms follow a standard notation in
which all electron-containing atomic
subshells are placed in a sequence.

8. What is orbital diagram?
 An orbital filling diagram is the more visual way to
represent the arrangement of all the electrons in a
particular atom. In an orbital filling diagram, the
individual orbitals are shown as circles (or squares)
and orbitals within a sublevel are drawn next to each
other horizontally. Each sublevel is labeled by its
principal energy level and sublevel. Electrons are
indicated by arrows inside the circles. An arrow
pointing upwards indicates one spin direction, while a
downward pointing arrow indicates the other
direction.

9. Example of electron configuration

10. Example of Orbital Diagram

11. Rules in writing electron configurations
1. Aufbau’s Principle – this is also known
as the “building up principle, states that
electrons occupy orbitals in order of
increasing energy.
It follows the electron distribution
mnemonic in filling up the orbital.

12. Electron Distribution Mnemonics

13. Example:
Write the electron configuration of
the following:
a. Li – 3
1s2 2s1
b. Na – 11
1s2 2s2 2p6 3s1

14. 2. Pauli’s Exclusion principle – Electrons
occupying the same orbital must have
opposite spin
Example: a)Consider the electron
configuration of 3Li -1s2 2s1
Three Rules Applied in Deriving
Electron Configurations

15. Example b)
Consider the electron of Sodium:
1s2 2s2 2p6 3s1

16. 3. Hund’s Rule of Multiplicity
When electrons enter a sublevel with more than one
orbital, they will spread out to the available orbitals
with the same spin before pairing.
Example: Considering the electron configuration of
7N – 1s2 2s2 2p3
Three Rules Applied in Deriving
Electron Configurations

17. Electron Configuration and Orbital Diagram of
Lighter Elements

18. More Examples
Write the electron configuration and
draw the orbital diagram of the
elements below:
a. 13Al
b. 17Cl

19. a. 13Al
Electron Configuration
Orbital Diagram

20. b. 17Cl
Electron configuration
Orbital Diagram

21. Practical Application
 In everything that we do in life, we always
follow certain rules. As a student for example,
you need to follow the rules imposed by the
school. As a daughter/son, you need to follow
the rules imposed by your parents. And in this
time of pandemic, we also follow certain rules
such as wearing of facemask and face shield
every time we go out and when we are in
group.

22. Summary
 Electron configuration is an arrangement of electrons in a
successive sublevels and atomic orbitals. In writing
electron configuration electron distribution mnemonics is
used.
 Orbital Diagram is a pictorial descriptions of the electrons
in an atom.
 Orbital Diagram and electron configuration follow:
a. Aufbau principle
b. Pauli Exclusion Principle
c. Hunds Rule

23. Try this in ½ sheet of paper
A. Write the electron configuration and draw the
orbital diagram of the following elements
1. 26Fe
2. 8O
3. 20Ca
Note: Answer this for 5 mins. You can pause the
video while answering.

24. Let’s check
1. 26Fe – 1s2 2s2 2p6 3s2 3p6 4s2 3d6
1s 2s 2p 3s 3p 4s 3d
2. 8O - 1s2 2s2 2p4
1s 2s 2p

25. c. 20Ca – 1s2 2s2 2p6 3s2 3p6 4s2
1s 2s 2p 3s 3p 4s

26. Assignment:
1. What is valence configuration?
2. Explain how is periodic table used in
determining the valence configuration of an
element?

27. THANK YOU!