You will learn how to write:electron configurationnoble gas configurationorbital configurationLewis Dot

You will learn the principals of:AufbauHund’sPauli Exclusion

QUANTUM MECHANICS

It’s all about electrons Only electrons are involved with chemical reactions

Review electron: location charge symbol

Quantum # tell you 4 things: l. Main energy level 2. shape of orbit 3. orientation4. spin

Principle Quantum #: energy level of electron indicates distance from

nucleus

) 2 ) 8 ) 18 ) 32 )

2N2

ENERGY INCREASES AS ATOM GET BIGGER

Principle Quantum #: energy level of electron indicates distance from nucleus

) 2 ) 8 ) 18 ) 32 )

Principle quantum number represented by 2n2

7 periods on PT

7 energy levels for e-

Calculate #e- using 2n2

N represents energy level

Angular Momentum Quantum #

Indicates shape of orbit

s

p

d

f

S (can hold) 2e-

P (can hold) 6e-

D (can hold) 10e-

F (can hold) 14e-

Now that you have learned principle quantum number and angular momentum

quantum number you can now learn to write

“ Electron Configuration”

2 ) 8 ) 18 ) 32 )

1s2 ) 2s2 2p6 ) 3s2 3p6,3d10 ) 4s2 4p6 4d10 ) 5s2 5p6 5d10

B

O

Al

Aufbau Principle : an e- will occupy lowest level of energy available

4s2 will fill before 3d10

1s2 ) 2s2 2p6 ) 3s2 3p6, 4s2 3d10 4p6 5s2 4d10 5p6…

Cobalt

Krypton

Silver

1s2

2s2 2p6

3s2 3p6 3d10

4s2 4p6 4d10 4f14

5s2 5p6 5d10 5f14

6s2 6p6 6d10 6f14

7s2 7p6 7d10 7f14

Noble Gas NotationDid you notice how you had to write the first few electron configurations over and over?

Uck!!! Simplify using Noble Gas Notation

On periodic chart elements on far right are called … noble gases

He

Ne

Ar

Kr

Xe

Rn

The have nice complete energy levels with no e- left over. They do not react with anything.

To simplify electron configuration we can use the noble gases.

Na

P

Co

K

Magnetic Quantum # …orientation…x y z

1s2 , 2s2 2p6

px , py , pz

1s2, 2s2 2p6, 3s2 3p6 4s2, 3d10

dx2y2, dxy, dyz, dxz, dz2

Spin Quantum # … which way e- spins – ½ +½

Orbital Notation

Hund’s principle: orbitals of equal energy are each occupied by one e- before any orbitals are occupied by a 2nd e-.

Orbital notation shows magnetic & spin quantum #

Boron

Phosphorus

Chromium

Can you identify these elements….backwards

• 5p3

• 4s1

• 4d8

• 2p2

• 5p4

• 5d1

• 4d11

• 3d8

3 rules governing electron configuration

Aufbau Principle

Hund’s Principle :

Pauli’s Exclusion Principle:

.

Aufbau Principle

An electron occupies

The lowest-energy level that can receive it.

Hund’s Principle:• Orbital's of equal energy are occupied by one electron before

any orbital is occupied by a second electron

• and all electrons in single occupied orbital's must have the same spin.

Pauli’s Exclusion Principle:

No two electrons in the same atom

can have the same set of four quantum numbers.

Block location tells what orbital being filled. s p d f

Group location tells # of valence electrons

4s1

6s2

4p1

4p5

4s2 3d3

5s2 4d9

3 methods to represent electron locations

1. Electron configuration

2. Noble Gas configuration

3. Orbital Notation

Fourth and final….

Lewis Dot configuration

Lewis Dot configurationValence electrons: electrons in outer energy level.

**** only outside electrons involved in Chemical Reactions****

B

O

Al

K

Cl

There is a secret=== group # tells valence electrons

Ws. 4.5 Lewis Dot

1. Carbon

2. Nitrogen

3. Phosphorus

4. Sulfur

5. Aluminum

6. Krypton

7. Calcium

8. Sodium

9. Potassium

10.Fluorine

11.Silicone

12.Bromine

13.Beryllium

14.Sulfur

15.Chlorine

You will learn how to write:electron configurationnoble gas configurationorbital configurationLewis Dot

You will learn the principals of:AufbauHund’sPauli Exclusion