1. Electrons are important because they determine how elements will bond and react with other elements.  

2. Bohr versus the REAL THING
Electrons are important because they determine how elements will bond and react with other elements.   
Bohr versus the REAL THING

3. Quantum Mechanical Model of the Atom (today’s model)
Electrons DO occupy energy levels but their path is not definite; it is unknown!

4. Quantum Mechanical Model of the Atom (today’s model)
Electrons DO occupy energy levels but their path is not definite; it is unknown!
Heisenberg Uncertainty Principle - It is impossible to know the exact location and speed of an electron

5. Electron Configuration
Tells us the probable location of an element’s electrons.

6. Electron Configuration
Tells us the probable location of an element’s electrons.
If YOU were an electron….
Atom = school

7. Electron Configuration
Tells us the probable location of an element’s electrons.
If YOU were an electron….
Atom = school
Energy Levels = hallways

8. Electron Configuration
Tells us the probable location of an element’s electrons.
If YOU were an electron….
Atom = school
Energy Levels = hallways
Sub levels = classrooms
Does every classroom have the same size and shape?

9. Electron Configuration
Tells us the probable location of an element’s electrons.
If YOU were an electron….
Atom = school
Energy Levels = hallways
Sub levels = classrooms
Orbitals = desks

10. Electron Configuration
Tells us the probable location of an element’s electrons.
If YOU were an electron….
Atom = school
Energy Levels = hallways
Sub levels = classrooms
Orbitals = desks
Electrons = students

11. give the general distance from the nucleus
Energy Levels –
give the general distance from the nucleus
E N E R G Y

12. Energy Levels –
give the general distance from the nucleus
Sublevels – the areas within the energy levels where the electrons are found.

13. give the general distance from the nucleus
Energy Levels –
give the general distance from the nucleus
Sublevels – the areas within the energy levels where the electrons are found. s
“sphere”

14. 1 2 3 4 5 6 7 1s 1s 2s 3s 4s 5s 6s 7s

15. give the general distance from the nucleus
Energy Levels –
give the general distance from the nucleus
Sublevels – the areas within the energy levels where the electrons are found.
s p
“sphere”
“propeller”

16. 1 2 3 4 5 6 7 1s 1s 2s
2 p 3s
3 p 4s
4 p 5s
5 p 6s
6 p
7 p 7s

17. give the general distance from the nucleus
Energy Levels –
give the general distance from the nucleus
Sublevels – the areas within the energy levels where the electrons are found.
s p d
“sphere”
“propeller”
“double
propeller”

18. 1 2 3 4 5 6 7 1s 1s 2s
2 p 3s
3 p 4s
3 d
4 p 5s
4 d
5 p 6s
5 d
6 p
6 d
7 p 7s

19. give the general distance from the nucleus
Energy Levels –
give the general distance from the nucleus
Sublevels – the areas within the energy levels where the electrons are found.
s p d f
“sphere”
“propeller”
“double
propeller”
“flower”
(too complex)

20. 1 2 3 4 5 6 7 1s 1s 2s
2 p 3s
3 p 4s
3 d
4 p 5s
4 d
5 p 6s
5 d
6 p 7s
6 d
7 p 4f 5f

21. Electron Configuration
1s2
Energy Level –
Principal Quantum #
(possibilities are 1-7)

22. Electron Configuration
1s2
Energy Level –
Principal Quantum #
(possibilities are 1-7)
Sublevel
(s, p, d, or f)

23. Electron Configuration
1s2
# of electrons
s: 1 or 2
p: 1-6
d: 1-10
f: 1-14
Energy Level –
Principal Quantum #
(possibilities are 1-7)
Sublevel
(s, p, d, or f)

24. Electron Configuration
1s2
# of electrons
s: 1 or 2
p: 1-6
d: 1-10
f: 1-14
Energy Level –
Principal Quantum #
(possibilities are 1-7)
Sublevel
(s, p, d, or f)
If you add up all of the electrons, it should equal the atomic # of the element

25. Aufbau Principle
Electrons fill sublevels of the lowest energy first.

26. 1 2 3 4 5 6 7 1s 1s 2s
2 p 3s
3 p 4s
3 d
4 p 5s
4 d
5 p 6s
5 d
6 p 7s
6 d
7 p 4f 5f

27. Name the element and circle the sublevel with the highest energy:
_____ 1s2 2s2 2p6 3s2 3p6 4s2 3d6
_____ 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d6
_____ 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p3 Fe Os Bi

28. Write the electron configuration:Br Pb Er
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p2
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f11

29. Noble Gas Configuration – shortcut to electron configs based on the last noble gas.
Noble gases are found in Group 18.
Example:
[Ar] 4s2 3d8
Where [Ar] represents
Argon – the last noble gas filled

30. Name the element: S _____ [Ne] 3s2 3p4 _____ [Xe] 6s2 4f14 5d6 Os
_____ [Kr] 5s2 4d10 5p3 Os Sb

31. Write the noble gas configuration:Se Mo Ar
[Ar] 4s2 3d10 4p4
[Kr] 5s2 4d4
[Ne] 3s2 3p6

32. Orbital Notation – visually shows the location of the electrons.
Only 2 electrons fit in each orbital.
Example:
__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
[Xe] 6s f d p5
You must draw each orbital, even if it is empty.
Hund’s Rule –
One electron enters each orbital
until all orbitals have one electron
with parallel spins
Pauli Exclusion Principle –
No 2 electrons can have the
same location and same spin ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑
Energy
Levels
Sublevels
# of
Orbitals
Maximum
# of electrons s p d f
1 - 7 1 2
2 - 7 3 6
3 - 6 5 10
4 - 5 7 14

33. Draw the orbital notations for the following elements:
Fe –
O –

34. Lewis Dot Structures – shows the valence electrons.
Valence Electrons – outershell electrons
You can count valence electrons by looking at the group #. (if it’s a double digit, subtract 10)
Remember Hund’s Rule when drawing Lewis Dots BUT draw all “s” electrons together on the right.
Examples:
C Br Ba N