Electron Configurations
Electron Configurations
Shell
1
2
3
4
Sublevels
s
sp
spd
spdf
Electron Configurations
Orbitals
s
p
d
f
1
3
5
7
Electron Configurations
Electron Configurations
When you’re filling an
atom with electrons,
where do you put them?
Aufbau Principle
Rule 1:
Each electron occupies the
lowest energy level available.
Pauli Exclusion Principle
Rule 2:
Only two electrons per orbital,
and they must have opposite
spins.
Hund’s Rule
Rule 3:
In each sublevel, first put one
electron in each orbital, then
go back and start putting a
second electron in each.
Electron Configurations
Electron Configurations
STOP
Electron Configurations
We’re not going
to talk about atoms.
Electron Configurations
We are not even going
to think about atoms.
Electron Configurations
We’re going to book a concert.
Electron Configurations
Seating levels further from the
stage have more sections
Electron Configurations
Seating levels further from the
stage have more sections
Electron Configurations
Seating levels further from the
stage have more sections
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Section
S
P
D
F
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Section
S
P
D
F
Your ticket says ROW 3 - SEC P - SEAT 2.
Where is your seat?
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Section
S
P
D
F
Your ticket says ROW 3 - SEC P - SEAT 2.
Where is your seat?
STAGE
Row 1
Rule 1
Row 2
Row 3
Row 4
Row 5
Everybody wants to sit as close
to the stage as they can.
-Mr. Aufbau
STAGE
Row 1
Rule 2
Row 2
Row 3
Row 4
Row 5
Seats are in pairs. Every pair of
seats can hold only two people.
-Mr. Pauli
STAGE
Row 1
Rule 3
Row 2
Row 3
Row 4
Row 5
People would rather sit next to an empty
seat. But they will sit next to a stranger if
it means they can be in a better section.
-Mr. Hund
STAGE
Row 1
Order of filling
Row 2
Row 3
Row 4
Row 5
Which seats are really closest to the stage?
STAGE
Row 1
Order of filling
Row 2
Row 3
Row 4
Row 5
Which seats are really closest to the stage?
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Now let’s fill some seats!
STAGE
Row 1
Now let’s fill some seats!
Row 2
Row 3
Row 4
Row 5
You sold 25 tickets.
STAGE
Row 1
Now let’s fill some seats!
Row 2
Row 3
Row 4
Row 5
You sold 25 tickets.
Which seats are filled?
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Section
S
P
D
F
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Section
S
P
D
F
STAGE
Row 1
Row 2
Row 3
Row 4
3
4
Row 5
Section
S
P
D
F
STAGE
Row 1
Row 2
Row 3
Row 4
3
4
Row 5
4
5
Row 6
4
5
Row 7
5
6
This is the order that you will sell tickets.
STAGE
Row 1
Row 2
Row 3
Row 4
3
4
Row 5
4
5
Row 6
4
5
Row 7
5
6
This is the order that you will sell tickets.
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
3
4
5
6
4
5
6
7
S
D
P
4
5
F
This is the order that you will sell tickets.
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
3
4
5
6
4
5
6
7
S
D
P
4
5
F
We’re going to hire an usher to be in
charge of each row in our chart.
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
Helen
Neal
Aaron
3
4
5
6
4
5
6
7
S
D
Kris
Xavier
Ron
Unice
P
4
5
F
We’re going to hire an usher to be in
charge of each row in our chart.
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
Helen
Neal
Aaron
3
4
5
6
4
5
6
7
S
D
Kris
Xavier
Ron
Unice
P
4
5
F
We’re going to hire an usher to be in
charge of each row in our chart.
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
Helen
Neal
Aaron
3
4
5
6
4
5
6
7
S
D
Kris
Xavier
Ron
Unice
P
4
5
F
You sold 25 tickets.
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
Helen
Neal
Aaron
3
4
5
6
4
5
6
7
S
D
Kris
Xavier
Ron
Unice
P
4
5
F
Which seats are filled?
Which seats are filled?
Row
1
2
2
3
3
4
3
Section
S
S
P
S
P
S
D
Seats
2
2
6
2
6
2
5
Usher
Helen
Neal
Aaron
1S2 2S2 2P6 3S2 3P6 4S2 3D5
Which seats are filled?
Row
1
2
2
3
3
4
3
Section
S
S
P
S
P
S
D
Seats
2
2
6
2
6
2
5
Usher
Helen
Neal
Aaron
Aaron’s row is full, plus 4S2 3D5
Which seats are filled?
Row
1
2
2
3
3
4
3
Section
S
S
P
S
P
S
D
Seats
2
2
6
2
6
2
5
[Ar] 4S2 3D5
Usher
Helen
Neal
Aaron
STAGE
Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
Helen
Neal
Aaron
3
4
5
6
4
5
6
7
S
D
Kris
Xavier
Ron
Unice
P
4
5
F
Try some others!
Homework
Read Section 5.3
Practice Problems
18-22 on page 139