1. 3.3 Electron Configuration

2. 1s
2 s
3 s
4 s
5 s
6 s
7 s
2 p
3 p
4 p
5 p
6 p
7 p
3 d
4 d
5 d
6 d
4 f
5 f 5d
Color and label your blank periodic table 6d

4. Notes: Electron Configuration
These three principles govern the filling of orbitals by electrons:
Aufbau Principle: Electrons enter orbitals of lowest energy first.
Pauli Exclusion Principle: An atomic orbital contains a maximum of two electrons.
Hund’s Rule: When electrons occupy orbitals of equal energy, one electron enters each orbital until the orbital is filled.

5. There are a total of 7 energy levels (shells).
Each energy level contains a sublevel made up of orbitals.
These are the following sublevels (orbitals):
 orbitals (#)
 s (1) 
p (3)
d (5)
f (7)
 Maximum # of electrons
  2 6
10 
 14

6. Orbital notation represents the number of electrons and their spin
Orbital notation represents the number of electrons and their spin. Since only 2 electrons occupy the 1s orbital, and their spin is opposite, the orbital notation for helium is: written as
“1s2”
Arrows are used in opposite direction to show the opposite spin.
The orbital notation for boron, atomic number 5, is:
1s2 2s2 2p1

7. Noble Gas Configuration: The last noble gas before the element of interest is the noble gas we put in the brackets. For example the element aluminum (atomic number 13) we write:
[Ne] 3s2 3p1
Sulfur: [Ne] 3s2 3p4
Barium: [Xe] 6s2
Arsenic: [Ar] 4s2 3d10 4p3

8. Do not copy

9. Do not copy

10. Note the number of electrons and its energy level