Transcript Electron Configurations

32
32
18
18
8
Energy
2
8
6d
5f
7s
6p 7s
5d
4f
6s
5p 6s
4d
5s
4p
5s
3d
4s
4s
3p
6d
6p
5d
5p
4d
4p
3d
3p
3s
3s
2p
2s
2p
2s
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1s
5f
4f
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”
General Rules
6d
Aufbau Principle
7s
6p
5d
– Electrons fill the
lowest energy
orbitals first.
6s
4d
3p
5f
7s
6p
5d
6s
5p
5s
4p
4s
6d
4f
5p
Energy
– “Lazy Tenant
Rule”
5f
4d
5s
3d
4p
3d
4s
3p
3s
3s
2p
2p
2s
2s
1s
1s
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4f
General Rules
• Pauli Exclusion Principle
– Each orbital can hold TWO electrons with
opposite spins.
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Wolfgang Pauli
General Rules
• Hund’s Rule
– Within a sublevel, place one electron
per orbital before pairing them.
– “Empty Bus Seat Rule”
WRONG
RIGHT
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Electron Configurations
Orbital Filling
Element
1s
2s
2px 2py 2pz
3s
Electron
Configuration
H
1s1
He
1s2
Li
1s22s1
C
1s22s22p2
N
1s22s22p3
O
1s22s22p4
F
1s22s22p5
Ne
1s22s22p6
Na
1s22s22p63s1
Electron Configurations
Orbital Filling
Element
1s
2s
2px 2py 2pz
3s
Electron
Configuration
H
1s1
He
1s2
C
NOT CORRECT
1s22s1
Violates Hund’s
Rule
1s22s22p2
N
1s22s22p3
O
1s22s22p4
F
1s22s22p5
Ne
1s22s22p6
Na
1s22s22p63s1
Li
Maximum Number of Electrons
In Each Sublevel
Maximum Number of Electrons In Each Sublevel
Sublevel
Number of Orbitals
Maximum Number
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
Order in which subshells are filled
with electrons
1s
2s
2p
3s
3p
3d
4s
4p
4d
4f
5s
5p
5d
5f
6s
6p
6d
7s
2
2
6
2
6
2
10
6
2
10
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d …
4f
Sublevels
4d
Energy
6d
5f
7s
6p
5d
4f
6s
5p
4d
5s
4p
3d
4s
3p
6d
7s
6p
5d
6s
4f
n=3
5p
4p
3d
4s
3p
3s
4d
5s
4p
3d
4s
3p
3s
2p
2s
5f
Energy
n=4
2p
3s
2p
n=2
2s
2s
1s
1s
n=1
1s
4f
Sublevels
4d
s
p
s
d
p
s
n=4
f
d
p
Energy
s
n=3
4p
3d
4s
3p
3s
1s22s22p63s23p64s23d104p65s24d10…
2p
n=2
2s
n=1
1s
8
O
Notation
15.9994
• Orbital Diagram
O
8e-
1s
2s
• Electron Configuration
2
2
4
1s 2s 2p
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2p
16
Notation
S
32.066
• Longhand Configuration
S 16e- 1s2 2s2 2p6 3s2 3p4
Core Electrons
Valence Electrons
• Shorthand Configuration
S
16e
2
4
[Ne] 3s 3p
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Shorthand Configuration
(a.k.a Noble Gas Notation)
A neon's electron configuration (1s22s22p6)
B
third energy level
[Ne] 3s1
C
D
one electron in the s orbital
orbital shape
Na = [1s22s22p6] 3s1
electron configuration
Shorthand Configuration
(a.k.a Noble Gas notation)
Element symbol
Electron configuration
Ca
[Ar] 4s2
V
[Ar] 4s2 3d3
F
[He] 2s2 2p5
Ag
[Kr] 5s2 4d9
I
[Kr] 5s2 4d10 5p5
Xe
[Kr] 5s2 4d10 5p6
Fe
Sg
22p64s
[He] 2s[Ar]
3s223d
3p664s23d6
[Rn] 7s2 5f14 6d4
Periodic Patterns
s
1
2
3
4
5
6
7
p
1s
2s
f
2p
3s
d (n-1)
3p
4s
3d
4p
5s
4d
5p
6s
5d
6p
7s
6d
7p
6
(n-2) 7
4f
5f
1s
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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Periodic Patterns
• Example - Hydrogen
1
2
3
4
5
6
7
1
1s
1st Period
1st column
of s-block
s-block
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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.
1
2
3
4
5
6
7
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32
Periodic Patterns
• Example - Germanium
1
2
3
4
5
6
7
[Ar]
2
4s
10
3d
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2
4p
Ge
72.61
Stability
• Full energy level
• Full sublevel (s, p, d, f)
• Half-full sublevel
1
2
3
4
5
6
7
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Stability
• Electron Configuration Exceptions
– Copper
EXPECT:
[Ar] 4s2 3d9
ACTUALLY:
[Ar] 4s1 3d10
– Copper gains stability with a full
d-sublevel.
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Stability
• Electron Configuration Exceptions
– Chromium
EXPECT:
[Ar] 4s2 3d4
ACTUALLY:
[Ar] 4s1 3d5
– Chromium gains stability with a half-full
d-sublevel.
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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)
POP
QUIZ
Fill in the orbital boxes for an atom of nickel (Ni)
1s
2s
2p
3s
3p
4s
3d
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.
Answer Key
Write out the complete electron configuration for the following:
1) An atom of nitrogen 1s22s22p3
1s22s22p63s23p64s23d104p65s24d9
2) An atom of silver
3) An atom of uranium (shorthand)
[Rn]7s25f4
Fill in the orbital boxes for an atom of nickel (Ni)
1s
2s
2p
3s
3p
4s
3d
Which rule states no two electrons can spin the same direction in a single orbital?
Pauli exclusion principle