1. Squares on the Periodic Table

2. Electron Configurations
When two atoms interact, the electrons (not the nuclei) are interacting
More importantly the outside orbitals
The Valence Electrons
The orbitals fill up in a regular pattern
The outside orbital electron configuration repeats
So.. the properties of atoms repeat.

3. Rules for Filling
1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 6f 7s 7p 7d 7f 8s 8p 8d 8f

4. S- block s1 s2 Alkali metals all end in s1
Alkaline earth metals all end in s2
really have to include He but it fits better later
He has the properties of the noble gases

5. The P-block p1 p2 p3 p4 p6 p5

6. Transition Metals -d block

7. F - block f1 f5 f2 f3 f4 f6 f7 f8 f9 f10 f11 f12 f14 f13
inner transition elements f1 f5 f2 f3 f4 f6 f7 f8 f9
f10
f11
f12
f14
f13

8. Each row (or period) is the energy level for s and p orbitals1 2 3 4 5 6 7
Each row (or period) is the energy level for s and p orbitals

9. d orbitals fill up after previous energy level so first d is 3d even though it’s in row 41 2 3 4 5 6 7 3d

10. 1 2 3 4 5 6 7 4f 5f
f orbitals start filling at 4f

11. H 1 Li 3 Na 11 K 19 Rb 37 Cs 55 Fr 87
1s1
1s22s1
1s22s22p63s1
1s22s22p63s23p64s1
1s22s22p63s23p63d104s24p65s1
1s22s22p63s23p63d104s24p64d105s2 5p66s1
1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p67s1

12. 1s2
1s22s22p6
1s22s22p63s23p6
1s22s22p63s23p63d104s24p6
1s22s22p63s23p63d104s24p64d105s25p6
1s22s22p63s23p63d104s24p64d105s24f14 5p65d106s26p6 He 2 Ne 10 Ar 18 Kr 36 Xe 54 Rn 86

13. Writing Electron configurations the easy way
Yes there is a shorthand

14. Electron Configurations repeat
The shape of the periodic table is a representation of this repetition.
When we get to the end of the row the outermost energy level is full.
This is the basis for our shorthand

15. The Shorthand
Write the symbol of the noble gas before the element in brackets [ ]
Then the rest of the electrons.
Aluminum - full configuration
1s22s22p63s23p1
Neon (Ne) is the closest Noble Gas with a lower atomic mass
1s22s22p6
so Al is [Ne] 3s23p1

16. The Shorthand Sn- 50 electrons The noble gas before it is Kr
Takes care of 36
Next 5s2
Then 4d10
Finally 5p2
[ Kr ]
5s2
4d10
5p2

17. Practice
Write the shorthand configuration for S Mn Mo W

18. Electron configurations and groups
Representative elements have s and p orbitals as last filled
Group number = number of electrons in highest energy level
Transition metals- d orbitals
Inner transition- f orbitals
Noble gases s and p orbitals full

19. Try it! Do “Classifying Elements” worksheet
Do “Electron Configuration Practice”