Transcript Electron Configuration Notes File

Electron Orbits
Pick-up Sheets on the Table
Orbit Notes
Orbit cut-outs in notebook
Quantum Mechanics
Heisenberg Uncertainty Principle
 Impossible to know both the velocity and
position of an electron at the same time
Quantum Mechanics
Orbital (“electron cloud”)
 Region in space where there is 90%
probability of finding an e-
Orbital
Radial Distribution Curve
Quantum Numbers
Four
Quantum
Numbers:
 Specify the
“address” of
each
electron in
an atom
Pauli Exclusion Principle
No two electrons in an
atom can have the same
four quantum numbers.
Wolfgang Pauli
Quantum Numbers
Pauli Exclusion Principle
No two electrons in an atom can have the same 4
quantum numbers.
Each e- has a unique “address”:
1. Principal #
2. Ang. Mom. #
3. Magnetic #
4. Spin #




energy level
sublevel (s,p,d,f)
specific orbital
electron
Quantum Numbers
1. Principal Quantum Number ( n )
 Energy level
 Size of the orbital
 n2 = # of orbitals in
the energy level
Principal Quantum Number
Generally symbolized by n, it denotes the shell
(energy level) in which the electron is located.
Number of electrons
that can fit in a shell:
2n2
Quantum Numbers
2. Angular Momentum Quantum # ( l )
 Energy sublevel
 Shape of the orbital
s
p
d
f
S orbit
Sphere
Hold 2 Electron in 1 orbit
P Orbit
Dumbell Shape
Hold 2 electrons in 3 orbits
Total of 6 Electrons
d-orbital
X shape
5 orbitals that hold 2 electrons each
10 total e-
F-orbital
Flower Shape
7 orbitals that hold 2 electrons each
14 total electrons
Quantum Numbers
3. Magnetic Quantum Number ( m or ml )
Orientation of orbital
Specifies the exact plane that the orbit
is on
C. Johannesson
Quantum Numbers
4. Spin Quantum Number ( ms )
Electron spin  +½ or -½
An orbital can hold 2 electrons that spin in
opposite directions.
C. Johannesson
Electron Configurations
Configuration
Notes
Configuration
Practice
C. Johannesson
Orbital filling table
Periodic Patterns
Example - Hydrogen
1
2
3
4
5
6
7
1st column of
s-block
1
1s
1st Period
s-block
C. Johannesson
Electron configuration of the elements of the
first three series
Steps to Writing Electron Configuration
1. Determine the # of electrons
2. Use the redesigned PT to get the configuration
3. Superscripts will equal the electrons
Periodic Patterns
s
p
1
2
3
4
5
6
7
f (n-2)
d (n-1)
6
7
© 1998 by Harcourt Brace & Company
C. Johannesson
Notation
Longhand Configuration
S 16e-
2
1s
2
2s
Core Electrons
6
2p
S
4
3p
Valence Electrons
Shorthand Configuration
16e
2
3s
2
4
[Ne] 3s 3p
C. Johannesson
Periodic Patterns
Example - Germanium
1
2
3
4
5
6
7
[Ar]
2
4s
10
3d
C. Johannesson
2
4p
Orbital Notation - shows the position of each electron in the
orbitals
Use the electron Configuration
1. draw boxes for the sublevel…
1 for s, 3 for p, 5 for d and 7 for f.
2. Fill the orbits with arrows to represent electrons.
A. General Rules
Pauli Exclusion Principle
Each orbital can hold TWO electrons with opposite
spins.
C. Johannesson
A. General Rules
Aufbau Principle
Electrons fill the
lowest energy
orbitals first.
C. Johannesson
General Rules
Hund’s Rule
Within a sublevel, place one e- per orbital before pairing
them.
WRONG
C. Johannesson
RIGHT
Notation
Orbital Diagram
O
8e-
1s
2s
Electron Configuration
2
2
4
1s 2s 2p
C. Johannesson
2p
Examples
H
Li
C
F
Ne
P
Mn