unit 5: light and electron...
TRANSCRIPT
C H E M I S T R Y
2 0 1 4 - 1 5
M R . R O N G
Unit 5: Light and Electron Configuration
Historical Models of the Atom
Dalton Thomson Rutherford Bohr
What do you notice about where the electrons are?
Bohr Model
How many electrons can fit in a level?
Energy levels Maximum # of Electrons
1 2
2 8
3 18
Lewis Structures
Hog Hilton
Congratulations, managers of the Hog Hilton! You’ve successfully booked rooms for all our guests!
Now let’s learn how this relates to how electrons fit within the atom.
States of Electrons
Normally, an electron is at the lowest state of energy possible, the ground state.
If energy is added, an electron can move an energy level and is then considered to be in an excited state.
States of Electrons
Since this is unstable, when the electron falls back down, it emits energy in the form of light.
Hog Hilton
Pauli Exclusion Principle:
No 2 electrons can have exactly the same “energy address” (same 4 quantum numbers).
To be in the same orbital, they must have opposite spins.
Hog Hilton
Aufbau Principle:
Fill lower sublevels before moving up electrons to higher sublevels
Hog Hilton
Hund’s Rule:
Electrons are placed in individual orbitals before they are paired up.
Maximum Number of Electrons In Each Sublevel Maximum 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
General Rules
Aufbau Principle
Electrons fill the
lowest energy
orbitals first.
“Lazy Tenant
Rule”
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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
4d 5s
5p
6s
7s
6p
6d
4f
5f
5d
En
erg
y
Energy Level Diagram of a Many-Electron Atom
Arbitrary
Energy Scale
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
General Rules
Pauli Exclusion Principle
Each orbital can hold TWO electrons with opposite spins.
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Wolfgang Pauli
RIGHT WRONG
General Rules
Hund’s Rule
Within a sublevel, place one electron per orbital
before pairing them.
“Empty Bus Seat Rule”
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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”
O
8e-
Orbital Diagram
• Electron Configuration
1s2 2s2 2p4
Notation
1s 2s 2p
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O 15.9994
8
Orbital Filling
Element 1s 2s 2px 2py 2pz 3s Configuration
Orbital Filling
Element 1s 2s 2px 2py 2pz 3s Configuration
Electron Configurations
Electron
H
He
Li
C
N
O
F
Ne
Na
1s1
1s22s22p63s1
1s22s22p6
1s22s22p5
1s22s22p4
1s22s22p3
1s22s22p2
1s22s1
1s2
NOT CORRECT Violates Hund’s
Rule
Electron Configurations
Electron
H
He
Li
C
N
O
F
Ne
Na
1s1
1s22s22p63s1
1s22s22p6
1s22s22p5
1s22s22p4
1s22s22p3
1s22s22p2
1s22s1
1s2
Orbital Filling
Element 1s 2s 2px 2py 2pz 3s Configuration
Electron Configurations
Electron
H
He
Li
C
N
O
F
Ne
Na
1s1
1s22s22p63s1
1s22s22p6
1s22s22p5
1s22s22p4
1s22s22p3
1s22s22p2
1s22s1
1s2
Energy Level Diagram A
rbitra
ry E
ne
rgy 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
Energy Level Diagram A
rbitra
ry E
ne
rgy 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 = 1s1
Hydrogen
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy 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
He = 1s2
Helium
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy 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
Li = 1s22s1
Lithium
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy 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
C = 1s22s22p2
Carbon
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy S
cale
1s
2s 2p
3s 3p
4s 4p 3d
5s 5p 4d
6s 6p 5d 4f
NUCLEUS
Electron Configuration
CLICK ON ELEMENT TO FILL IN CHARTS
N
N = 1s22s22p3
Bohr Model
Nitrogen
Hund’s Rule “maximum
number of unpaired
orbitals”.
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy 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
F = 1s22s22p5
Fluorine
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy 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
Al = 1s22s22p63s23p1
Aluminum
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy S
cale
1s
2s 2p
3s 3p
4s 4p 3d
5s 5p 4d
6s 6p 5d 4f
NUCLEUS
Electron Configuration
CLICK ON ELEMENT TO FILL IN CHARTS
N
Ar = 1s22s22p63s23p6
Bohr Model
Argon
H He Li C N Al Ar F Fe La
Energy Level Diagram A
rbitra
ry E
ne
rgy S
cale
1s
2s 2p
3s 3p
4s 4p 3d
5s 5p 4d
6s 6p 5d 4f
NUCLEUS
CLICK ON ELEMENT TO FILL IN CHARTS
Fe = 1s22s22p63s23p64s23d6
N
H He Li C N Al Ar F Fe La
Bohr Model
Iron
Electron Configuration
Energy Level Diagram A
rbitra
ry E
ne
rgy S
cale
1s
2s 2p
3s 3p
4s 4p 3d
5s 5p 4d
6s 6p 5d 4f
NUCLEUS
CLICK ON ELEMENT TO FILL IN CHARTS
La = 1s22s22p63s23p64s23d10
4s23d104p65s24d105p66s25d1
N
H He Li C N Al Ar F Fe La
Bohr Model
Lanthanum
Electron Configuration
s p
d (n-1)
f (n-2) 6
7
Periodic Patterns
1s
2s
3s
4s
5s
6s
7s
3d
4d
5d
6d
1s
2p
3p
4p
5p
6p
7p
4f
5f
1
2
3
4
5
6
7
Periodic Patterns
Period #
energy level (subtract for d & f)
A/B Group #
total # of valence e-
Column within sublevel block
# of e- in sublevel
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s-block 1st Period
1s1 1st column
of s-block
1
2
3
4
5
6
7
Periodic Patterns
Example - Hydrogen
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Full energy level
1
2
3
4
5
6
7
• Full sublevel (s, p, d, f)
• Half-full sublevel
Stability
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