1. Energy Levels & Orbitals

2. The Hydrogen Orbitals
Orbitals do not have sharp boundaries.

3. The Hydrogen Orbitals Hydrogen has discrete energy levels.
Called principal energy levels
Labeled with whole numbers
photon - An elementary particle, the quantum of the electromagnetic interaction and the basic unit of light. In other words a photon is a little packet of energy which can carry light.

4. The Hydrogen Orbitals
Each principal energy level is divided into sublevels.
Labeled with numbers and letters
Indicate the shape of the orbital

5. The Hydrogen Orbitals
The s and p types of sublevel

6. The Hydrogen Orbitals
Hydrogen Orbitals
Why does an H atom have so many orbitals and only 1 electron?
An orbital is a potential space for an electron.
Atoms can have many potential orbitals.

7. The Wave Mechanical Model: Further Development
Atoms Beyond Hydrogen
The Bohr model was discarded because it does not apply to all atoms.

8. The Wave Mechanical Model: Further Development
Pauli Exclusion Principle - an atomic orbital can hold a maximum of 2 electrons and those 2 electrons must have opposite spins

9. General Rules Pauli Exclusion Principle
Each orbital can hold TWO electrons with opposite spins.

10. General Rules WRONG RIGHT Hund’s Rule
Within a sublevel, place one e- per orbital before pairing them.
“Empty Bus Seat Rule”
WRONG
RIGHT

11. General Rules Aufbau Principle
Electrons fill the lowest energy orbitals first.
“Lazy Tenant Rule”

12. Sublevel Orbitals s----------- p----------- d----------- f-----------1 3 5 7

13. Electron Arrangements in the First 18 Atoms on the Periodic Table
Classifying Electrons
Valence electrons – electrons in the outermost (highest) principal energy level of an atom
Core electrons – inner electrons
Elements with the same valence electron arrangement show very similar chemical behavior.

14. 1s2 2s2 2p4 O Notation 1s 2s 2p 8e- Orbital Notation
Electron Configuration
1s2 2s2 2p4

16. S 16e- 1s2 2s2 2p6 3s2 3p4 S 16e- [Ne] 3s2 3p4 Notation Core Electrons
Longhand Configuration
S 16e-
1s2
2s2
2p6
3s2
3p4
Core Electrons
Valence Electrons
Shorthand Configuration
S 16e- [Ne] 3s2 3p4

17. Electron Configurations and the Periodic Table
Orbital filling and the periodic table

18. 1 2 3 4 5 6 7 s p
d (n-1) 6 7
f (n-2)

20. Periodic Patterns p s d (n-1) f (n-2) Shorthand Configuration
Core e-: Go up one row and over to the Noble Gas.
Valence e-: On the next row, fill in the # of e- in each sublevel. s
d (n-1)
f (n-2) p

21. Periodic Patterns
Example - Germanium
[Ar]
4s2
3d10
4p2

22. H atom Electron configuration – electron arrangement – 1s1
Orbital diagram – orbital is a box grouped by sublevel containing arrow(s) to represent electrons

23. He atom
Electron configuration– 1s2
Orbital diagram

24. Li atom
Electron configuration– 1s2 2s1
Orbital diagram

25. H He Li C N O F Energy Level Diagram Bohr Model Arbitrary Energy Scale
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p
2s p 1s
Electron Configuration
NUCLEUS
H He Li C N O F
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26. Electron Configuration
Energy Level Diagram
Hydrogen
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p 1s
Electron Configuration
NUCLEUS
H = 1s1
H He Li C N Al Ar F Fe La
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27. Electron Configuration
Energy Level Diagram
Helium
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p 1s
Electron Configuration
NUCLEUS
He = 1s2
H He Li C N Al Ar F Fe La
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28. Electron Configuration
Energy Level Diagram
Lithium
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p 1s
Electron Configuration
NUCLEUS
Li = 1s22s1
H He Li C N Al Ar F Fe La
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29. Electron Configuration
Energy Level Diagram
Carbon
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p 1s
Electron Configuration
NUCLEUS
C = 1s22s22p2
H He Li C N Al Ar F Fe La
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30. Electron Configuration
Energy Level Diagram
Nitrogen
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
Hund’s Rule “maximum
number of unpaired orbitals”.
2s p
Electron Configuration 1s
NUCLEUS
N = 1s22s22p3
H He Li C N Al Ar F Fe La
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31. Electron Configuration
Energy Level Diagram
Fluorine
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p
Electron Configuration 1s
NUCLEUS
F = 1s22s22p5
H He Li C N Al Ar F Fe La
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32. Electron Configuration
Energy Level Diagram
Aluminum
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p
Electron Configuration 1s
NUCLEUS
Al = 1s22s22p63s23p1
H He Li C N Al Ar F Fe La
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33. Electron Configuration
Energy Level Diagram
Argon
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p 1s
Electron Configuration
NUCLEUS
Ar = 1s22s22p63s23p6
H He Li C N Al Ar F Fe La
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34. Electron Configuration
Energy Level Diagram
Iron
6s p d f
Bohr Model
5s p d
4s p d
Arbitrary Energy Scale
3s p N
2s p 1s
Electron Configuration
NUCLEUS
Fe = 1s22s22p63s23p64s23d6
H He Li C N Al Ar F Fe La
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35. Electron Configuration
Energy Level Diagram
Lanthanum
6s p d f
Bohr Model
5s p d
4s p d N
Arbitrary Energy Scale
3s p
2s p 1s
Electron Configuration
NUCLEUS
La = 1s22s22p63s23p64s23d6
4s23d104p65s24d105p66s25d1
H He Li C N Al O F Fe La
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36. B. Electron Configurations and the Periodic Table
Look at electron configurations for K through Kr

37. Electron Configurations and the Periodic Table

38. C. Periodic Patterns Period # A/B Group # Column within sublevel block
energy level (subtract for d & f)
A/B Group #
total # of valence e-
Column within sublevel block
# of e- in sublevel

39. Atomic Properties and the Periodic Table
Metals and Nonmetals
Metals tend to lose electrons to form positive ions.
Nonmetals tend to gain electrons to form negative ions.

40. Atomic Properties and the Periodic Table
Atomic Size
Size tends to increase down a column.
Size tends to decrease across a row.

41. Atomic Properties and the Periodic Table
Ionization Energies
Ionization Energy – energy required to remove an electron from an individual atom (gas)
Tends to decrease down a column
Tends to increase across a row