iv. electron configuration electrons in atoms. a. general rules zpauli exclusion principle yeach...
TRANSCRIPT
IV. Electron Configuration
Electrons in Atoms
A. General Rules
Pauli Exclusion Principle
Each orbital can hold 2 electrons
with opposite spins.
“Opposites Attract”
A. General Rules
Aufbau Principle
Electrons fill the lowest energy orbitals first.
“Lazy Tenant Rule”
A. General Rules
More on Aufbau
Order Orbitals Fill
RIGHTWRONG
A. General Rules
Hund’s Rule
Within a sublevel, place one e- per orbital before pairing them.
“Empty Bus Seat Rule”
H
1e-
Orbital Diagram
Electron Configuration
1s1
B. Notation
1s
He
2e-
Orbital Diagram
Electron Configuration
1s2
B. Notation
1s
Li
3e-
Orbital Diagram
Electron Configuration
1s2 2s1
B. Notation
1s 2s
Be
4e-
Orbital Diagram
Electron Configuration
1s2 2s2
B. Notation
1s 2s
B
5e-
Orbital Diagram
Electron Configuration
1s2 2s2 2p1
B. Notation
1s 2s 2p
C
6e-
Orbital Diagram
Electron Configuration
1s2 2s2 2p2
B. Notation
1s 2s 2p
N
7e-
Orbital Diagram
Electron Configuration
1s2 2s2 2p3
B. Notation
1s 2s 2p
O
8e-
Orbital Diagram
Electron Configuration
1s2 2s2 2p4
B. Notation
1s 2s 2p
F
9e-
Orbital Diagram
Electron Configuration
1s2 2s2 2p5
B. Notation
1s 2s 2p
Ne
10e-
Orbital Diagram
Electron Configuration
1s2 2s2 2p6
B. Notation
1s 2s 2p
Shorthand Configuration
S 16e-
Valence Electrons
Core Electrons
S 16e- [Ne] 3s2 3p4
1s2 2s2 2p6 3s2 3p4
B. Notation
Longhand Configuration
B. Notation
Practice with Electron Configuration
Worksheet
© 1998 by Harcourt Brace & Company
nsnp
(n-1)d
(n-2)f
n=1n=2n=3n=4n=5n=6n=7
C. Periodic Patterns
C. Periodic Patterns
Period # energy level (subtract for d & f)
Column within sublevel block # of e- in sublevel
s-block
1st Period
1s11st column of s-block
C. Periodic Patterns
Example - Hydrogen
1
2
3
4
5
6
7
C. Periodic Patterns
Shorthand Configuration Core e-: Go up one row and over to the Noble Gas.
Valence e-: On the next row, fill in the # of e- in each sublevel.
[Ar] 4s2 3d10 4p2
C. Periodic Patterns
Example - Germanium
C. Periodic Patterns
Periodic Patterns Activity
Most stable = Full energy level
1
2
3
4 5
6
7
Full sublevel (s, p, d, f)Half-full sublevel
D. Stability
Electron Configuration Exceptions
Copper
EXPECT: [Ar] 4s2 3d9
ACTUALLY: [Ar] 4s1 3d10
Copper gains stability with a full d-sublevel.
D. Stability
Electron Configuration Exceptions
Chromium
EXPECT: [Ar] 4s2 3d4
ACTUALLY: [Ar] 4s1 3d5
Chromium gains stability with a half-full d-sublevel.
D. Stability
D. Stability
Ion Formation Atoms gain or lose electrons to become
more stable. Isoelectronic with the Noble Gases.
O2- 10e- 1s2 2s2 2p6
D. Stability
Ion Electron Configuration
Write the e- config for the closest Noble Gas
EX: Oxygen ion O2- Ne
D. Stability
Practice with Stability & Electron Configuration Worksheet