1. Electron Configuration

2. Quantum Number
Number that specifies the properties of the atomic orbitals
Tells us the distance from the nucleus and the shape of the orbital

3. Principal Quantum Number
Main level or shell
These are the Bohr energy levels
n = 1, n = 2, n = 3
As n increases, the distance from the nucleus increases

4. Sublevel Each main level is divided into sublevels
Four types of sublevels s p d f

5. S orbitals
Spherical

6. P orbitals
Dumbell shaped
One dumbell in each axis

7. P Orbitals

8. D orbitals

9. F orbitals

10. Orbital Each sublevel is made of orbitals
Every orbital can hold 2 electrons

11. s – 1 orbital – 2 electrons
p – 3 orbitals – 6 electrons
d – 5 orbitals – 10 electrons
f – 7 orbitals – 14 electrons

12. Main Level
Sublevel
# orbitals
# e in
sublevel
Total e

13. Electron Configuration
Arrangement of electrons in an atom
Aufbau Principle – electrons fill into an atom starting with the lowest energy levels

14. Electron Configuration Polka
F:\Documents\electron configuration.avi

15. Electron Spin Way which the electrons rotate on their axis
Pauli Exclusion Principle – in order for two electrons to occupy the same orbital, they must have opposite spin
Write configuration for C S

16. Higher Order
There are exceptions to the order of filling as you move to higher levels Br

17. Valence Electrons Electrons in the last main energy level
These are the electrons involved in chemical reactions
There are a maximum of 8 valence electrons

18. How to find valence e-
Write configuration and count electrons in last main energy level
Examples: Find valence electrons for C Fe Cl

19. Draw Dot Structure C Fe Cl

20. Periodic Table

21. Demitri Mendeleev First to publish a chart of the elements
Arranged by increasing atomic mass with similar elements in columns

22. Moseley’s Table
He suggested that the elements are arranged by atomic number rather than atomic mass
Periodic Law – chemical and physical properties are periodic functions of their atomic numbers

23. Table Properties Horizontal Rows are called Periods
Vertical Columns are called Groups or Families
For every group or family, the electron arrangement is the same

24. Configuration from the Table
Group tells end configuration, period tells tells the highest energy level
Ca in group 2 period 4 so it ends in 4s2

25. Blocks
Chart is broken into blocks based on the orbitals they fill last
Groups 1 and 2 fill s last – called s block
Groups 3 –12 called d block
Groups 13 – 18 called p block
Bottom two rows are the f block

26. Name the element with the following end configuration
5s1
2s22p3
4s23d6
3s23p6
6s25d9