1. Quantum Mechanics

2. Can only refer to the probability of finding an e- in a region of space. Cannot specify the path
4 Quantum #’s are required to describe the energy of any electron in an atom (Pauli Exclusion Principle)
No 2 e-’s can have the same 4 #’s

3. Quantum Mechanics Heisenberg Uncertainty Principle
Impossible to know both the velocity and position of an electron at the same time

4. 1st Quantum Number (n) Given by the energy level
n= 1,2,3,4 to infinity
Value of n is the main factor in determining the energy of an electron therefore, its average distance from the nucleus.

5. 2nd Quantum Number (l) p s d f Angular momentum Gives the sublevel (l)
l= n-1
n=1,2,3,4
l =0,1,2,3
Value of l=
letter s p d f f d s p

6. Magnetic Quantum Number ( ml )
Orientation of orbital
Specifies the exact orbital within each sublevel

7. 3rd Quantum Number (ml) Magnetic quantum number
l=0 s sublevel ml=0 only one suborbital
l=1 p sublevel ml=-1,0,+1
3 suborbitals
l=2 d sublevel ml=-2,-1,0,1,2
5 suborbitals
l=3 f sublevel m1=-3,-2,-1,0,1,2,3
7 suborbitals

8. 4th Quantum Number (ms)
Spin Number
½ or -1/2

9. Feeling overwhelmed?
Read Section 4-2!

10. For example
Orbital Diagram 1s 2s 2p O
8e-