This document provides information on electron configuration and the quantum mechanical model of the atom. It discusses electron configuration notation which uses symbols of orbitals and superscripts to indicate the number of electrons in each orbital. It also covers various principles like the Aufbau principle, Pauli exclusion principle, and Hund's rule. Additionally, it defines the four quantum numbers - principal, angular, magnetic, and spin quantum numbers - which describe the properties of electrons in atomic orbitals. It also gives examples of orbital shapes and capacities for different principle quantum levels.

2. Anagrams

3. Electron Location

4. Electron Configuration
 It is the assignment of all of the electrons
in an atom into specific shells and
subshells
 Uses symbols of the orbitals and the
number of electrons (written of
superscripts) that occupy each orbital.

5. 1s1
subshell
Number of
electrons in
the orbital
Principal energy
level

6. Maximum electrons per subshell
s = 2 e-
p = 6 e-
d = 10 e-
f = 14 e-

8. Exercise
First 10!!

9. Orbital Diagram/ Orbital
Notation
 Consists of boxes and arrows that
represent the orbitals and the electrons,
respectively.
 The up and down orientations of the
arrows represent the two magnetic spins
of the electrons.

10.  Clockwise rotation  Counter clockwise
rotation

11. s
p

12. Aufbau Principle
 States that electrons should occupy first
the orbitals with lower energy before those
with higher energy.
 Example, 1s orbital should be filled first
before the 2s orbital.
 4s orbital has lower energy than the 3d
orbital.

13. Pauli exclusion principle
 States that no two electrons in an atom can
possess the same set of quantum numbers.
 This principle emphasizes the significance of the
spin quantum numbers.
 If two electrons in an atom have the same n, l,
and ml, they should still have different ms.
 One electron must have ms= -1/2 and the other
should be ms= +1/2

14. Hund’s rule of maximum
multiplicity
 Suggests that the most stable
arrangement of electrons in subshells is
the one with the greatest number of
parallel spins.
 This means that each orbital in a subshell
is singly occupied before pairing of
electrons occurs.

15. Exercise
First 10!!

16. Quiz!!

17. Quiz # 6 (1/2 crosswise)
Write the electron
configuration and draw the
orbital diagram of the elements
with atomic number 21 to 25.

18. Louis de Broglie
 Initially thought that electrons behave both
like a wave and a particle.
 However, he later emphasized that
electrons behave more like a wave.
 Proposed that electrons be considered as
a wave confined in the space surrounding
an atomic nucleus.

19. Ernst Schrödinger 1887-1961
 Quantum Mechanical Model
1926
Electrons are in probability zones
called “orbitals”, not orbits and
the location cannot be pinpointed
Electrons are particles and waves
at the same time
Developed quantum numbers
based on theories of Einstein and
Planck
Werner Heisenberg 1901-1976

20. Orbitals

21. Quantum Mechanical Theory
Electron in a Hydrogen atom

22.  Quantum number describe the atomic
orbitals as well as the properties of the
electrons in those orbitals.
Quantum Numbers

23.  Principal quantum number (n) - describes the
SIZE of the orbital or ENERGY LEVEL of the
atom.
 Angular quantum number (l) or sublevels -
describes the SHAPE of the orbital.
 Magnetic quantum number (m) - describes an
orbital's ORIENTATION in space.
 Spin quantum number (s) - describes the SPIN
or direction (clockwise or counter-clockwise) in
which an electron spins.
Quantum Numbers

24. Principle Quantum Number (n) or
Energy Level
 integer values used to specify the shell/size/level
the electron is in
 describes how far away from the nucleus the
electron shell or level under consideration is
 the lower the number, the closer the energy level
is to the atom's nucleus and less energy
 maximum # of electrons that can fit in an energy
level is given by formula 2n2

27. Angular/Azimuthal Quantum
Number (l) or Sub-level
 determines the shape of the orbital
 they are numbered but are also given
letters referring to the orbital type
l=0 refers to the s-orbitals
l=1 refers to the p-orbitals
l=2 refers to the d-orbitals
l=3 refers to the f-orbitals

29. Orbital Letter Designation
l Letter Maximum
Number of
Electrons
0 s 2
1 p 6
2 d 10
3 f 14

30. Magnetic quantum number (ml)
or Orbitals
 the third of a set of quantum numbers
 tells us how many orbitals there are of a
particular type and their orientation in
space of a particular orbital
 only two electrons can fit in an orbital
 = electron

31. S – orbitals
only holds two electrons

32. P – orbitals
holds up to six electrons

33. http://www.ul.ie/~walshem/fyp/porbital.gif
P - orbitals

34. D – orbitals
holds up to 10 electrons

36. F – orbitals
holds up to 14 electrons

38. http://www.shsu.edu/~chm_tgc/BbAIF/PDB
s/applet/PDBorbitals.html

40. Spin quantum number (s)
 the fourth of a set of quantum numbers
 number specifying the direction of the spin
of an electron around its own axis.
only two electrons of opposite spin may
occupy an orbit
the only possible values of a spin quantum
number are +1/2 or -1/2.

42. Principle
Quantum # (n)
LEVEL/SIZE 1 2 3 4
Angular
Quantum # (l)
ORBITAL
SHAPE or
SUBLEVEL
s s p s p d s p d f
Magnetic
Quantum #
(m)
AXIS/
ORIENTATION
or ORBITALS
1
1
orbital
1 3
4 total
orbitals
1 3 5
9 total orbitals
1 3 5 7
16 total orbitals
Spin
Quantum # (s)
DIRECTION
OF
ELECTRON
SPIN
2 e- 8 e- 18 e- 32 e-

43. Table 3-6b Orbitals and Electron Capacity of the First Four Principle Energy
Levels
Principle
energy
level (n)
Type of
sublevel
Number of
orbitals
per type
Number of
orbitals
per
level(n2)
Maximum
number of
electrons
(2n2)
1 s 1 1 2
2
s 1
4 8
p 3
3
s 1
9 18
p 3
d 5
4
s 1
16 32
p 3
d 5
f 7

45. Writing quantum mechanical
model of an atom
 STEP 1: Give the ground state
electron configuration.
 STEP 2: Give the orbital diagram.
 STEP 3: Determine its quantum
numbers (n, l, ml, ms)

46. Quiz!!