1. QUANTUM MECHANICAL MODEL
Determines the allowed energies an electron can have
Determines how likely it is to find the electron in various locations

2. QUANTUM MECHANICAL MODEL
CLOUD or ORBITAL MODEL
PROPABILITY OF FINDING AN ELECTRON WITHIN A CERTAIN VOLUME OF SPACE AROUND THE NUCLEUS (orbital)
High density =high propability
Low density =low probability
Shape of the cloud represents a 90% probability

3. QUANTUM MECHANICAL MODEL GENERAL PLAN
PRINCIPLE ENERGY LEVEL (n)
ENERGY SUBLEVELS (l)
indicate the shape of orbital which contains
ATOMIC ORBITALS (m)
Orientation of orbital around nucleus
(Electrons found here)
Number of electrons per atomic orbital =2

4. QUANTUM MECHANICAL MODEL principle energy levels
LABELED BY PRINCIPLE QUANTUM NUMBERS (n) n=1,2,3,4,5,6,etc.
As n> the electrons energy > and distance from nucleus >
Can be called a shell
Within a given energy level there may be several sublevels that have orbitals

5. QUANTUM MECHANICAL MODEL energy sublevels
ENERGY SUBLEVEL (l)
Each energy sublevel corresponds to orbitals of different shapes where the electron is likely to be found
Sublevel could be called a subshell

6. QUANTUM MECHANICAL MODEL energy sublevels
ENERGY SUBLEVEL (l)
(Orbital shapes)
Labeled by letters
s = spherical shape
p = dumbbell shape
d = clover leaf +
f = too complicated

7. QUANTUM MECHANICAL MODEL atomic orbitals
ATOMIC ORBITAL (m)
(Orbital orientation)
THE s SUBLEVEL HAS ONLY ONE ORBITAL, s

8. QUANTUM MECHANICAL MODEL atomic orbitals
Atomic orbital (orbital orientation)
THE p SUBLEVEL HAS THREE ORBITALS—px, py, pz

9. QUANTUM MECHANICAL MODEL atomic orbitals
Atomic orbital (orbital orientation)
THE d SUBLEVEL HAS 5 ORBITALS– dxy, dxz, dyz, dx2-y2,dz2

10. QUANTUM MECHANICAL MODEL atomic orbitals
Atomic orbital(orbital orientation)
THE f SUBLEVEL HAS 7 ORBITALS
They are too complicated to show or name

11. QUANTUM MECHANICAL MODEL electron location
Within each orbital there can be a maximum of 2 electrons
EACH ELECTRON MUST HAVE AN OPPOSITE SPIN-+1/2 or -1/2

12. QUANTUM MECHANICAL MODEL RELATIONSHIPS
Relationships between
Energy levels n=energy level
SUBLEVELS n=number OF SUBLEVELS
ORBITALS n2=number OF ORBITALS PER ENERGY LEVEL
ELECTRONS 2n2= MAXIMUM NUMBER OF ELECTRONS PER ENERGY LEVEL
Energy Level #sublevels # orbitals and type # electrons
n=1
n=2
n=3
n=4

13. QUANTUM MECHANICAL MODEL SUMMARY
Organization
Designation
Principle energy level (shell)
Sublevel (subshell)
Atomic orbital
Spin

14. Energy Level
Subshells or sublevel
# of Orbitals
Maximum number of
e-s per orbital
Total number of
e-s per energy level
n = 1
n = 2
n = 3
n = 4

15. QUANTUM MECHANICAL MODEL
Electron configuration
The relationship between energy and stability
Electrons and nucleus interact to make the most stable arrangment possible (lowest energy)
There are three rules for electron configurations

16. QUANTUM MECHANICAL MODEL
Electron configuration
Aufbau princple
Electrons occupy the orbitals of lowest energy first

17. QUANTUM MECHANICAL MODEL
AUFBAU RULE

18. QUANTUM MECHANICAL MODEL
AUFBAU ORDER FILLING

19. QUANTUM MECHANICAL MODEL
Electron configuration
Pauli exclusion principle
One orbital may describe at most 2 electrons
To occupy the same orbital, the two electrons must have opposite spins ↑↓

20. QUANTUM MECHANICAL MODEL
Electron configuration
Hunds rule
When filling orbitals of equal energy, one electron occupies each orbital until all orbitals contain one electron with the same spin direction

21. QUANTUM MECHANICAL MODEL
Electron arrangement
Orbital notation
Electron configuration notation
Exceptions
Half-filled sublevels are less stable than filled sublevels but more stable than other configurations