electron configurations h = 1s 1 1s1s he = 1s 2 1s1s li = 1s 2 2s 1 1s1s 2s2s be = 1s 2 2s 2 1s1s...

H = 1s1

1s

He = 1s2

1s

Li = 1s2 2s1

1s 2s

Be = 1s2 2s2

1s 2s

C = 1s2 2s2 2p2

1s 2s 2px 2py 2pz

S = 1s2 2s2 2p4

1s 2s 2px 2py 2pz 3s 3px 3py 3pz

THIS SLIDE IS ANIMATEDIN FILLING ORDER 2.PPT

H = 1s1

1s

He = 1s2

1s

Be = 1s2 2s2

1s 2s

+1e-

+2e-

e-

+4e-

e-e-

e-

Coulombic attraction holds valence electrons to atom.

Coulombic attraction holds valence electrons to atom.

Valence electrons are shielded by the kernel electrons. Therefore the valence electrons are not held as tightly in Be than in He.

Fe = 1s1 2s22p63s23p64s23d6

1s 2s 2px 2py 2pz 3s 3px 3py 3pz

+26

e-

e-

e-

e-

4s 3d 3d 3d 3d

Iron has ___ electrons.26

3d

ArbitraryEnergy Scale

18

18

32

8

8

2

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

e-

e-e-

e-

e- e-

e-

e-

e-

e-

e-

e-

e-e-

e-

e-

e-

e-

e- e-

e-

e-

Orbital Filling

Element 1s 2s 2px 2py 2pz 3s Configuration

Orbital Filling


Electron ConfigurationsElectron

H

He

Li

C

N

O

F

Ne

Na

1s1

1s22s22p63s1

1s22s22p6

1s22s22p5

1s22s22p4

1s22s22p3

1s22s22p2

1s22s1

1s2

NOT CORRECTViolates Hund’s

Rule


H

He

Li

C

N

O

F

Ne

Na

1s1

1s22s22p63s1

1s22s22p6

1s22s22p5

1s22s22p4

1s22s22p3

1s22s22p2

1s22s1

1s2

Orbital Filling



H

He

Li

C

N

O

F

Ne

Na

1s1

1s22s22p63s1

1s22s22p6

1s22s22p5

1s22s22p4

1s22s22p3

1s22s22p2

1s22s1

1s2

Filling Rules for Electron Orbitals

Aufbau Principle: Electrons are added one at a time to the lowest energy orbitals available until all the electrons of the atom have been accounted for.

Pauli Exclusion Principle: An orbital can hold a maximum of two electrons.To occupy the same orbital, two electrons must spin in opposite directions.

Hund’s Rule: Electrons occupy equal-energy orbitals so that a maximum number of unpaired electrons results.

*Aufbau is German for “building up”







18

18

32

8

8

2

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

North

S

South

N

- -

Spin Quantum Number, ms

North

South

The electron behaves as if it were spinning about an axis through its center.This electron spin generates a magnetic field, the direction of which dependson the direction of the spin.

Brown, LeMay, Bursten, Chemistry The Central Science, 2000, page 208

- -S

N

Electron aligned with magnetic field,

ms = + ½

Electron aligned against magnetic field,

ms = - ½

Energy Level Diagram of a Many-Electron Atom


18

18

32

8

8

2

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 177

Maximum Number of Electrons In Each SublevelMaximum Number of Electrons In Each Sublevel

Maximum Number Sublevel Number of Orbitals of Electrons

s 1 2

p 3 6

d 5 10

f 7 14

LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 146

Quantum Numbers

n shell

l subshell

ml orbital

ms electron spin

1, 2, 3, 4, ...

0, 1, 2, ... n - 1

- l ... 0 ... +l

+1/2 and - 1/2

Order in which subshells are filled with electrons

1s

2s

3s

4s

5s

6s

7s

2p

3p

4p

5p

6p

3d

4d

5d

6d

4f

5f

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d … 2 2 6 2 6 2 10 6 2 10

4f

4d

4p

4s

n = 4

3d

3p

3s

n = 3

2p

2s

n = 2

1sn = 1

En

erg

y

Sublevels

2s

3s

4s

5s

6s

7s

1s

2p

3p

4p

5p

6p

3d

4d

5d

6d

4f

5f

1s

2s2p

3s

3p4s

4p3d

4d5s

5p6s

7s6p

6d

4f

5f

5d

En

erg

y

4f

4d

4p

4s

n = 4

3d

3p

3s

n = 3

2p

2s

n = 2

1sn = 1

En

erg

y

Sublevels

s

s

s

s

p

p

p

d

d f

1s22s22p63s23p64s23d104p65s24d10…

Energy Level Diagram of a Many-Electron Atom


18

18

32

8

8

2

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 177

Electron capacitiesElectron

capacities

Copyright © 2006 Pearson Benjamin Cummings. All rights reserved.

Electron capacitiesElectron

capacities

Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

3232

1818

88

2

Energy Level Diagram

Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model

Electron Configuration

CLICK ON ELEMENT TO FILL IN CHARTS

N

H He Li C N Al Ar F Fe La


Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

H = 1s1

Hydrogen



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

He = 1s2

Helium



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

Li = 1s22s1

Lithium



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

C = 1s22s22p2

Carbon



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS



N

N = 1s22s22p3

Bohr Model

Nitrogen

Hund’s Rule “maximum number of unpaired

orbitals”.



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

F = 1s22s22p5

Fluorine



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

Al = 1s22s22p63s23p1

Aluminum



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS



N

Ar = 1s22s22p63s23p6

Bohr Model

Argon



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS


Fe = 1s22s22p63s23p64s23d6

N


Bohr Model

Iron



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS


La = 1s22s22p63s23p64s23d10

4s23d104p65s24d105p66s25d1

N


Bohr Model

Lanthanum


neon's electron configuration (1s22s22p6)

Shorthand Configuration

[Ne] 3s1

third energy level

one electron in the s orbital

orbital shape

Na = [1s22s22p6] 3s1 electron configuration

AA

BB

CC

DD

Shorthand Configuration

[Ar] 4s2

Electron configurationElement symbol

[Ar] 4s2 3d3

[Rn] 7s2 5f14 6d4

[He] 2s2 2p5

[Kr] 5s2 4d9

[Kr] 5s2 4d10 5p5

[Kr] 5s2 4d10 5p6

[He] 2s22p63s23p64s23d6

Ca

V

Sg

F

Ag

I

Xe

Fe [Ar] 4s23d6

General Rules

• Pauli Exclusion PrinciplePauli Exclusion Principle

– Each orbital can hold TWO electrons with

opposite spins.

Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

Wolfgang Pauli

General Rules

Aufbau PrincipleAufbau Principle

– Electrons fill the lowest energy orbitals first.

– “Lazy Tenant Rule”


2s

3s

4s

5s

6s

7s

1s

2p

3p

4p

5p

6p

3d

4d

5d

6d

4f

5f

1s

2s

2p

3s

3p

4s

4p

3d

4d5s

5p6s

7s

6p

6d

4f

5f

5d

En

erg

y

RIGHTWRONG

General Rules

• Hund’s RuleHund’s Rule

– Within a sublevel, place one electron per orbital before pairing them.

– “Empty Bus Seat Rule”


O

8e-

• Orbital Diagram

• Electron Configuration

1s1s22 2s2s22 2p2p44

Notation

1s 2s 2p


O15.9994

8

• Shorthand Configuration

S 16e-

Valence ElectronsValence ElectronsCore ElectronsCore Electrons

S 16e- [Ne] 3s2 3p4

1s2 2s2 2p6 3s2 3p4

Notation

• Longhand Configuration


S32.066

16

sp

d (n-1)

f (n-2) 67

Periodic Patterns

11ss

22ss

33ss

44ss

55ss

66ss

77ss

33dd

44dd

55dd

66dd

11ss

22pp

33pp

44pp

55pp

66pp

77pp

44ff

55ff

1234567

Periodic Patterns

• Period #– energy level (subtract for d & f)

• A/B Group # – total # of valence e-

• Column within sublevel block– # of e- in sublevel


s-block1st Period

1s11st column of s-block

Periodic Patterns

• Example - Hydrogen


1

2

3

4

5

6

7

Periodic Patterns

• Shorthand Configuration– Core electrons:

• Go up one row and over to the Noble Gas.

– Valence electrons: • On the next row, fill in the # of e- in each sublevel.


[Ar] 4s2 3d10 4p2

Periodic Patterns

• Example - GermaniumGermanium


Ge72.61

32

• Full energy level

1

2

3

4

5

6

7

• Full sublevel (s, p, d, f)• Half-full sublevel

Stability


This fills the valenceshell and tends to givethe atom the stabilityof the inert gasses.

The Octet Rule

Atoms tend to gain, lose, or share electrons until they have eight valence electrons.

8

ONLY ss- and pp-orbitals are valence electrons.

• Electron Configuration Exceptions– Copper

EXPECT: [Ar] 4s2 3d9

ACTUALLY: [Ar] 4s1 3d10

– Copper gains stability with a full d-sublevel.

Stability


• Electron Configuration Exceptions– ChromiumChromium

EXPECT: [Ar] 4s2 3d4

ACTUALLY: [Ar] 4s1 3d5

– Chromium gains stability with a half-full d-sublevel.

Stability


Electron Filling in Periodic Table

K4s1

Ca4s2

Sc3d1

Ti3d2

V3d3

Mn3d5

Fe3d6

Co3d7

Ni3d8

Cr3d4

Cu3d9

Zn3d10

Ga4p1

Ge4p2

As4p3

Se4p4

Br4p5

Kr4p6

1

2

3

4

s

d

p

s

Cr4s13d5

Cu4s13d10

4f

4d

4p

4s

n = 4

3d

3p

3s

n = 3

2p

2sn = 2

1sn = 1

Ene

rgy

4s 3d

Cr4s13d5

4s 3d

Cu4s13d10

Cr3d5

Cu3d10

Stability

• Ion Formation– Atoms gain or lose electrons to become more

stable.– Isoelectronic with the Noble Gases.


O2- 10e- [He] 2s2 2p6

Stability

• Ion Electron Configuration

– Write the e- configuration for the closest Noble Gas

• EX: Oxygen ion O2- Ne


Orbital Diagrams for Nickel

2s 2p 3s 3p 4s 3d1s

2s 2p 3s 3p 4s 3d1s

2s 2p 3s 3p 4s 3d1s

2s 2p 3s 3p 4s 3d1s

Excited State

Pauli Exclusion

Hund’s Rule

Ni58.6934

28

2 2 6 2 6 2 8

2 2 6 2 6 1 9

Orbital Diagrams for Nickel

2s 2p 3s 3p 4s 3d1s

2s 2p 3s 3p 4s 3d1s

2s 2p 3s 3p 4s 3d1s

2s 2p 3s 3p 4s 3d1s

Excited State

VIOLATES Pauli Exclusion

VIOLATES Hund’s Rule

Ni58.6934

28

2 2 6 2 6 2 8

2 2 6 2 6 1 9

Write out the complete electron configuration for the following:1) An atom of nitrogen

2) An atom of silver

3) An atom of uranium (shorthand)

Fill in the orbital boxes for an atom of nickel (Ni)

2s 2p 3s 3p 4s 3d1s

Which rule states no two electrons can spin the same direction in a single orbital?

Extra credit: Draw a Bohr model of a Ti4+ cation.

Ti4+ is isoelectronic to Argon.

POP QUIZ

Write out the complete electron configuration for the following:1) An atom of nitrogen

2) An atom of silver

3) An atom of uranium (shorthand)

Fill in the orbital boxes for an atom of nickel (Ni)

2s 2p 3s 3p 4s 3d1s

Which rule states no two electrons can spin the same direction in a single orbital?

1s22s22p3

1s22s22p63s23p64s23d104p65s24d9

[Rn]7s26d15f3

Extra credit: Draw a Bohr model of a Ti4+ cation. 22+n = n

Pauli exclusion principle

Ti4+ is isoelectronic to Argon.

Answer Key

electron configurations h = 1s 1 1s1s he = 1s 2 1s1s li = 1s 2 2s 1 1s1s 2s2s be = 1s 2 2s 2 1s1s...

Documents

s n electron

f nucleus ee

s north south

f nucleus north s south

valence electrons

electron configurations

electron spin

kernel electrons