The document outlines the development of the quantum mechanical model of the atom, focusing on how it describes the energies and positions of electrons through various quantum numbers. Key contributions from physicists like Niels Bohr, Erwin Schrödinger, and Werner Heisenberg are highlighted, including the uncertainty principle and the mathematical equations that define electron behavior. Additionally, the document includes a group activity and assessments related to quantum numbers and their connection to the periodic table.

1. Development of the
Electronic Structure of
the Atom

2. Objectives:
Explain how the Quantum
Mechanical model of the
atom describe the energies
and positions of the
electrons.

3. GUESS WHAT?

4. E R N E S T
R U T H E R F O R D
R N
T H R O D

5. N I E L B O H R
N L B H

6. E L E C T R O N
C L O U D
E C O
C O D

7. E L E C T R O N
C O N F I G U R A T I O N
L E R
O N I U I O N

8. B O H R M O D E L
O R O L

9. Question: using this
model, do you think it
would be possible to tell
the exact location of the
electrons?

10. In 1926 Erwin Schrödinger, an Austrian physicist, took the
Bohr atom model one step further. Schrödinger used
mathematical equations to describe the likelihood of finding an
electron in a certain position. This atomic model is known as
the quantum mechanical model of the atom.

11. GROUP ACTIVITY – QUANTUM
MODEL OF ATOM
AND
GROUP PRESENTATION

12. - In 1911, 25 years of age Niels Bohr received
his Ph. D in Physics.
- He believed that electron can jump in other
orbit by absorbing and emitting a photon of
light with exactly correct energy content.
- Bohr’s model fitted well in hydrogen atom
ONLY.

13. Louie de Broglie proposed that the
electron (which is thought of as a
particle) could also be thought of as
a wave.

14. Schrodinger used this idea to
develop a mathematical equation
to describe the hydrogen atom.

15. Werner Karl Heisenberg discovered that
for a very small particle like the electron,
its location cannot be exactly known and how
it is moving, thus he was able to formulate the
Heisenberg’s uncertainty principle.

16. The quantum mechanical model also
gives information about the energy of
the electron and describes the region
of space around the nucleus as
consisting of shells, known as the
principal or main energy levels.
s (sharp), p (principal), d
(diffuse), and f (fundamental).

18. Schrodinger’s Equation
Quantum Numbers – describe electrons within
corresponding to the orbital size, shape and orientation in
space
1.Principal Quantum Number
2.Angular Momentum Quantum Number
3.Magnetic Quantum Number
4.Electron Spin Quantum Number

19. PRINCIPAL QUANTUM
NUMBER (n)
- Designating the shell the
electron is occupying.
- The smaller the value of “n”
has a lower energy. The
bigger the value of “n” has
a highest energy.
FORMULA: n – 1
Possible values: 1,2,3,4…
Example:
If n=7, what is the principal
electron shell?

20. ANGULAR MOMENTUM
QUANTUM NUMBER (L)
- Describes the shape of
orbitals.
- Related to Principal
Quantum Number and
allowing the number of
zero to n – 1.
L = 0, 1, 2, 3
always start at 0 to get a value of L.
s orbit (0) – Sharp
- spherical shape
p orbit (1) – Principal
- dumbbell shape
(2 lobes)
d orbit (2) – Diffuse
- 4 lobes with
variety of shapes
f orbit (3) – Fundamental
- more complex
shapes
The greater the value of ‘n’ the larger is
the sphere.

21. Example:
If n=4, what is the value of L?

22. MAGNETIC QUANTUM NUMBER (mL)
- Describes the orientation of the orbital sound around the nucleus.
If the Angular Momentum Quantum Number reached to 3 (L – 3),
The Magnetic Quantum Number value…
mL = -3, -2, -1, 0, +1, +2, +3
- Don’t forget to put a negative (-) & positive (+) signs.
Example:
If n = 3 and L = 2, then what are the possible values of mL?

23. ELECTRON SPIN QUANTUM NUMBER (ms)
- Indicates the direction the electron is
spinning. A positive electron has an upward
spin, which can be referred to as “spin up”,
when it is negative electron has a
downward spin can be referred to as “spin
down”.
- Only two possible answer for this quantum.
+ 1 & -1 called “spin paired electron”
2 2

24. ASSESSMENT:
Answer the following questions.
1. If n=8, what is the principal electron shell?
2. If n=8 and L=7, then what are the possible values of mL?
3. If n=7, what is the value of L?
4. List the possible combinations of all four quantum numbers when n=8,
L=7, mL=6.
5. Explain how the Quantum Numbers related to each other, and relate
it to the periodic table.