1. Electron Configurations and Orbital diagrams

2. When doing electron configuration remember we follow the periodic table

3. So lets do the electron configuration for Sulfer
2p6
3s2
3p4
1s22s22p63s23p4

4. So lets do the electron configuration for iron
2p6
3s2
3p6
4s1
1s22s22p63s23p64s1

5. When you have the larger elements such as Bromine or iodine, this could take a lot of writing.
Writing the configurations is very repetitive.
You just keep adding the elements and rows
Is there an easier way to write this.
Why yes there is
Noble Gases

6. Noble Gases Found in Group 8 of the periodic table
The valence shells of the Nobel gases are completely filled
So like nobility-They are content. Don’t need to bond with any other element because they are full –their valence shell is anyway.

7. Short hand configuration-AKA-Nobel Gas configurations
I can use my Nobel gases to write my electron configurations
Example
Iodine
Regular Electron Configuration
1s12s22p63s23p64s23d104p65s24d105p5
Short Hand Configuration
[Kr] 5s24d105p5

8. Short hand configuration-AKA-Nobel Gas configurations
Write the shorthand configuration, or the Nobel Gas configuration for
Chlorine
[Ne] 3s23p5
Bromine
[Ar]4s23d104p5

9. The Big Questions
Now that we know how electrons are arranged into atoms, how are they arranged into sublevels and orbitals?
How can we communicate the arrangement of atoms in orbitals?

10. Review Electrons arranged into energy levels.
n = 1, n = 2, n = 3, etc...
Energy levels broken into sublevels.
n = 1 made of 1s.
n = 2 made of 2s and 2p.
n = 3 made of 3s, 3p, and 3d.
n = 4 made of 4s, 4p, 4d, and 4f.

11. Review
In an atom, electrons fill the lowest sublevels first (aufbau principle).
Fill higher energy sublevels only when lower ones are already filled.
Order of filling is not as expected.

12. Order of Sublevel Filling5p 7p
5p6 4f
4f14 7s 5s 3d
5s2
4d10
3d10 3p
4p6
3p6 4d 3s
3s2
4s2 4p 4s
6s2 6p 6d 6s
2p6 2p 2s
2s2
Electron Configuration for Platinum (Element 78) 1s
1s2

13. Hund’s Rule
In a sublevel, every orbital gets one electron before any orbital gets a pair.
Example:
Electron configuration for carbon: 1s2 2s2 2p2 1s 2s 2p
orbitals
sublevel
energy level

14. Hund’s Rule electron config. for oxygen: 1s22s22p4 1s 2s 2p orbitals
sublevel
energy level

15. Orbital Diagrams
Show the arrangement of electrons in orbitals within an atom.
Use boxes to represent orbitals.
One arrow (↑) represents 1 electron.
2 arrows (↑↓) rep. 2 electrons.

16. Orbital Diagrams
So like with electron configuration, orbital diagrams follow similar rules
In the s level-you can only fit 2 electron, when doing orbital diagrams you have one box that can only fit two arrows
In the p level-you can only fit 6 electrons so you have three boxes
In the d level-you can only fit 10 electrons so you have five boxes
In the f level-you can only fit 14 electrons so you have seven boxes
Each box can fit two arrow, however, you have to fill in each box with one arrow first before you can place the second arrow.

17. Orbital Diagrams
Orbital diagram for hydrogen.
electron config: 1s1 1s

18. Orbital Diagrams
Orbital diagram for helium.
electron config: 1s2 1s

19. Orbital Diagrams Orbital diagram for lithium. electron config: 1s2 2s1

20. Orbital Diagrams Orbital diagram for beryllium.
electron config: 1s2 2s2 1s 2s

21. Orbital Diagrams Orbital diagram for carbon.
electron config: 1s2 2s2 2p2 1s 2s 2p

22. Orbital Diagrams Orbital diagram for magnesium.
electron config: 1s2 2s2 2p6 3s2 1s 2s 2p 3s