1. Electrons in Atoms

2. Quantum Theory
EQ: What is the relationship between energy levels and sublevels?

3. A. Atomic Orbitals
Home for electrons

4. A. Atomic Orbitals
Principal Quantum Number (n) = major energy level (rows in P-Table)
Each principal energy level has Energy sublevels (shapes)

5. S orbital

6. P orbitals

7. D orbitals

8. F orbitals

9. B. Sublevel Shapes sublevel Shape # of orbitals s Spherical 1 p Peanut3 d
daisy 5 f
flower 7

10. C. Sublevels and “n”
The # of energy levels tells you how many sublevels (shapes) you have n
# of sublevels
Which sublevels? 1 1 1s 2 2 2s 2p 3 3 3s 3p 3d 4 4 4s 4p 4d 4f

11. D. Sublevels and electrons
Each orbital can hold two electrons
sublevel
# of orbitals
# electrons s 1 2 p 3 6 d 5 10 f 7 14

12. Electron configuration (1)
How do you write electron configurations?

13. A. Orbital Diagrams 1s 2s 2p Show the arrangement of electrons
1st Energy Level 1s
1 shape
2nd Energy Level 2s
2 shapes 2p

14. B. Rules Electrons fill the lowest energy orbitals first.
1. Aufbau (Build up) Principle
Electrons fill the lowest energy orbitals first.

15. B. Rules 2. Pauli Exclusion Principle
Each orbital can hold TWO electrons with opposite spins.

16. B. Rules
3. Hund’s Rule
Within a sublevel, place one e- per orbital before pairing them.
WRONG
RIGHT

17. C. Electron Configuration
Orbital Diagram 1s 2s 2p O
8e-
Ground State Electron Configuration
1s2 2s2 2p4
Ground State = lowest possible energy

18. e- configuration practice 1
Element
e- configuration
Bohr
Diagram
orbital Diagram H He Be F S Cl Mg Si

19. s p d (n-1) f (n-2) D. Periodic Patterns 1 2 3 4 5 6 7 6 7
© 1998 by Harcourt Brace & Company

20. D. Periodic Patterns p s d (n-1) f (n-2)
© 1998 by Harcourt Brace & Company

21. 1s1 D. Periodic Patterns 1st column of s-block 1st Period s-block
Example - Hydrogen
1s1
1st column of s-block
1st Period
s-block

22. D. Periodic Patterns
Example: S
1s2
2s2
2p6
3s2
3p4

23. D. Periodic Patterns
Example: Ge
1s2
2s2
2p6
3s2
3p6
4s2
3d10
4p2

24. Group Work: Write the e- config forA B C D E
# 1 Si N Ca Ne
# 2 In I Ru La Sn
# 3 Nd Re Rf Pu Ho
Person

25. Noble Gases
E. Notation 8A He Ne Ar Kr Xe Rn

26. E. Notation
Example - Ge (Noble gas notation)
[Ar]
4s2
3d10
4p2

27. S 16e- 1s2 2s2 2p6 3s2 3p4 S 16e- [Ne] 3s2 3p4 E. Notation
Longhand
S 16e-
1s2
2s2
2p6
3s2
3p4
Core Electrons
Valence Electrons
(inside)
(outside)
Shorthand (Noble gas configuration)
S 16e- [Ne] 3s2 3p4

28. E. Notation
Core electrons
Valence electrons

29. F. Stability Copper EXPECT: [Ar] 4s2 3d9 ACTUALLY: [Ar] 4s1 3d10
1. Full sublevel
Copper
EXPECT: [Ar] 4s2 3d9
ACTUALLY: [Ar] 4s1 3d10
Copper gains stability with a full d-sublevel.

30. F. Stability EXPECT: [Ar] 4s2 3d4 ACTUALLY: [Ar] 4s1 3d5
2. Half-Full Sublevel
Chromium
EXPECT: [Ar] 4s2 3d4
ACTUALLY: [Ar] 4s1 3d5
Cr gains stability with a half-full d-sublevel.

31. F. Stability

32. G. Electron Dot Structures
Show # valence electrons
Ex: Sulfur = [Ne] 3s23p4
It has 6 valence electrons S

33. e- configuration practice 2
Element
E-config
(Longhand)
Dot
structure
Noble gas
(shorthand) #
valence e- N
Skip 3 lines Se
Skip 4 lines Sr Pd Mo Ag