Chapter 4:
Quantum Mechanical
Model
Foldable #2
1 Key Concepts
5 Explanation
6
2
7
8
3
9
4
10
11
front
Definition
12
inside
Background
13
14
15
16
back
1
A star will tell you
where to write your
notes in the foldable.
Quantum Mechanical Model
oatomic model in which electrons are
treated as waves
came up with it?
Who?
oLouis de Broglie – “wave theory”
Electrons have particle AND wave-like
properties
●
oErwin Schrodinger
Created equation to treat hydrogen’s
electron as a wave
●
14 -15
Why?
othe wave equation is drawn as an
“electron cloud” it shows the probability of
finding the electron
16
More connections to line spectra
oThe big gaps correspond to the energy
released when an electron jumps from one
energy level to another.
oThe closely spaced lines represent the
movement of electrons from levels that are not
very different in energy, or sublevels.
A sublevel is a division within an energy level.
●
Key Concepts for Foldable
1
The Quantum Mechanical Model can
be broken down into 4 parts:
Energy level
2
Sublevel
3
4
Orbital
Electron Spin (3 rules of orbital box
diagrams)
Energy Level =
6
oRow number on the periodic table
8
Sublevel =
Block on the periodic table
Increasing Energy
As size increases, energy
increases.
1s
2s
lower energy
2p
3p
3s
higher energy
4p
10
Orbital
Sublevel:
# of orbitals
it contains:
s
p
d
f
1
3
5
7
oOrbitals within a sublevel have the same
energy, but different orientation (spin).
9
Note:
The d and f orbitals are more complex and
do not all have the same shape.
To review…
oEach energy level consists of one or more
sublevels and each sublevel consists of
one of more orbitals.
oThere are…
1 orbital in an s sublevel
●3 equal-energy orbitals in a p sublevel
●5 equal-energy orbitals in a d sublevel
●7 equal-energy orbitals in a f sublevel
●
How to Write Electron
Configuration
Steps:
1. start at H
2. travel row by row
3. list row number
4. list “letter” of block (s,p,d,f)
5. count over the number of squares
Blocks on Periodic Table
S
s
p
d
f
Blocks on Periodic Table
S
s
p
d
f
Blocks on Periodic Table
S
s
p
d
f
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3 Rules of Orbital Box
Diagrams
oAufbau Principle – electrons are added one at a
time to the lowest energy levels first
oPauli Exclusion Principle – an orbital can hold a
maximum of 2 electrons with opposite spin
oHund’s Rule – electrons occupy equal energy
orbitals singly before pairing
Orbital Box Diagram
o A way of showing how electrons fill orbitals
3s
2p
2s
1s
What is Oxygen electron
configuration?
1. start at H
2. travel row by row
3. list row number
4. list “letter” of block (s,p,d,f)
5. count over the number of squares
Oxygen’s Electron configuration:
1s22s22p4
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2p
2s
1s
Orbital Box Diagram
According to the Pauli Exclusion Principle…
o Put 2 arrows in each box maximum
o Arrows in opposite directions to represent spin
3s
2p
2s
1s
Orbital Box Diagram
According to Aufbau…
o Start at bottom, not top
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s
Orbital Box Diagram
According to Hund…
o Put arrows in one at a time before pairing
them up
3s
2p
2s
1s