1. Electron Configuration
What is it?
A list of orbitals that contain electrons for an element.
Ex. 1s22s22p63s1
What are the different ways:
Orbital notation _______ 1s
Complete configuration 1s22s22p63s1
Abbreviated configuration(noble gas configuration) [He] 2s2

2. S orbitals are spherical
Lowest energy orbital

3. P orbitals are dumbell shaped

4. D orbitals

5. F orbitals (highest energy orbital level)

6. Rules of Electron Configuration
1. Afbau principle
An electron occupies the lowest energy orbital that can receive it.
2. Pauli exclusion principle
No two electrons in the same atom can have the same four quantum numbers.
3. Hund’s rule
Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron and all electrons in singly occupied orbitals must have the same spin state.

7. Notations Orbital Notation- Electron Configuration Notation
An unoccupied orbital is represented by ____
An orbital containing one electron is represented by ______ 1s
An orbital containing two electrons is represented by _______
Electron Configuration Notation
1s2 2s2 2p6

9. Steps 1. determine the number of electrons to be “addressed”.
2. Look at the template or periodic table and “count”
3. You must fill “up” arrows in the orbitals before filling “down” arrows.
4. The order of filling is 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p (these are lowest energy to highest)

10. Blocks on the periodic table
Can you find a pattern

11. Electron configuration practice

12. Additional items Isoelectric Outer shell configuration Diamagnetic
When these atoms lose or gain electrons, they would have the same number of electrons.
Outer shell configuration
Valence electrons orbitals and placement
Diamagnetic
When all of the electrons in orbitals are paired (up spin and down spin). If one is unpaired it is called paramagnetic)

13. Quantum Theory and Electron Configuration

14. Quantum model of the atom
Quantum theory of an atom
A theory that uses mathematical equations to describe wave properties of electrons and other small particles.
Quantum Numbers
These numbers completely describe orbitals.

15. Quantum numbers 4 sets of numbers house #, street, city, zip code
area code, prefix, number, extension
1. Principal quantum number
2. Angular momentum quantum number
3. magnetic quantum number
4. spin quantum number

16. Principal Quantum Number
Symbolized by n
Indicates the energy level of the electron
As n increases the electron’s energy and its distance from the nucleus increase.
1-7

17. Angular Momentum Quantum Number
Symbolized by l
Indicates the shape of the orbital in a specific energy level.
l = n-1
For l=0, s orbital (spherical)
For l=1, p orbital (dumbbell)
For l=2, d orbital
For l=3, f orbital

18. Magnetic Quantum Number
Symbolized by m
M numbers are whole, including 0 from –l to +l.
Indicates the orientation of an orbital around the nucleus.
S has only 1 possible orientation
P has 3 orientations
D has 5 orientations
F has 7 orientations

19. Spin Quantum Number Values are +1/2 and -1/2
Indicates direction of spin
2 electrons that are occupying the same orbital have to have opposite spins.