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Quantum Electron Model Chapter 5 Mr. Hines
Part A - INTRODUCTION TO THE QUANTUM ELECTRON MODEL
1 Recall basic knowledge from chapter 4 – energy levels, valence electrons, periods, and groups
2 Describe atoms using 2 dimensional space and 3 dimensional space.
3 Explain the spatial orientation of electrons as orbitals.
4 Distinguish between the different types/shapes of orbitals.
5 Determine the maximum number of electrons that each orbital can hold.
6 Speak and write common terminology – Coefficient, character, superscript
Part B – ADVANCED QUANTUM ELECTRON MODEL
7 Define the 2 methods for describing electron orbitals.
8 Define the 3 rules for writing electron configurations and orbital diagrams.
9 Write electron configurations and use shortcuts.
10 Write electron orbital diagrams.
11 Write the arrow diagram for electron structure.
12 Identify s, p, d, and f blocks on the periodic table.
13 Explain why the f block is located below the d block on a traditional periodic table.
14 Compare the quantum model of electrons to the classical model of the electrons.
15 Describe electrons in ground state compared to excited state.
16 Explain the what causes light (and the different colors of light)
PART A – INTRODUCTION TO THE QUANTUM ELECTRON MODEL
Vocabulary Parts C and D
Electron Nucleus Energy level Period Group horse
3-D Emit Orbital S orbital P orbital D orbital
Electron
configuration
Valence
electron
Spacial
orientation
Pauli exclusion
principle
Quantum
model
Coordinate
system
Opposite spin Ground state Excited state Light Electricity color
Superscript Coefficient Element Stable Noble gas 2-D
Quantum model Space calculator Location Coefficient Character
Superscript Clockwise Counterclockwise Proton Heat Mass
Sun Star Orbital diagram spin Hund’s rule Aufbau principle
Target 1- Recall basic knowledge from chapter 4 – energy levels, valence
electrons, periods, groups.
A. Electrons are found around the nucleus in 7 energy levels.
B. Each energy level can hold a certain amount of electrons before filled.
C. An element’s number of energy levels is equal to its period number.
D. The electrons in the outer most energy level of an element are called valence electrons.
E. An element’s number of valence electrons is equal to its group number.
Questions
1. How many energy levels does Phosphorus have? ________
2. How many valence electrons does Phosphorus have? _________
3. What Period is Phosphorus in? _______
4. What Group is Phosphorus in? _______
5. What is the pattern? _______________________________________________________
Target 2 - Describe the 3-dimensional model of the atom using the x, y, z axes.
A. So far we have used models of atoms in 2 dimensions (flat 2-D)
B. The real story of atoms is more complex and requires 3 dimensions (volumetric – 3D)
C. The quantum model of electrons requires 3 dimensions. Pg 131
D. To discuss 3-D space, we need a 3 coordinate system.
E. These coordinate systems are known as x, y, z axes.
Target 3 - Explain the spatial orientation of electrons as orbitals. A. Electrons exist in energy levels around the nucleus. Pg 131
B. Within the energy levels, electrons will occupy a specific space.
C. The 3-Dimensional space where electrons exist is called an orbital.
D. An orbital is the location in space around the nucleus where electrons exist.
E. These orbitals have different shapes and names.
F. An orbital’s shape describes the location of the specific electrons.
Target 4 - Distinguish between the different types/shapes of orbitals. A. Orbitals are specific locations around the nucleus where electrons exist; orbitals can have different
shapes.
B. The first orbital is the “s” orbital and is spherical (round).
C. The second orbital is the “p” orbital and these are dumbbell shaped.
D. The third orbital is the “d” orbital and these are balloon shaped.
E. The forth orbital is the “f” orbital and these are irregular in shape.
Orbital notes
Dog on chain
Questions
1. What is an orbital? _________________________________________________________
2. What does an orbital shape describe? ____________________________________________
3. What is the shape of an “s” orbital? _________________________
4. What is the shape of a “p” orbital? __________________________
5. What is the shape of a “d” orbital? __________________________
s orbitals p orbitals d orbitals
f orbitals - The seven f orbitals are not understood well enough to have agreement on their orientation in space. Their
directional characteristics are too complex to be shown – and are therefore not part of this course.
Target 5 - Determine the maximum number of electrons that each orbital can
hold. Remove answers for student version
Each orbital can only hold a certain amount of electrons.
Orbital Maximum electrons held
s 2
p 6
d 10
f 14
Target 6 - Speak and write common terminology – Coefficient, character,
superscript
1. Coefficient – a number or quantity placed (generally) before and multiplying another quantity
2. Character – a symbol (as a letter or number) that represents information; represents the orbital type for
this section
3. Example - 2S – 2 is the coefficient of S 4. Superscript – A number that is written above and to the right of a character.
5. Example – S2 - 2 is the superscript of S
Practice – Complete the chart
Character Coefficient Write it Character Superscript Write it
S 3 S 3
P 2 P 2
D 4 D 4
a 5.5 a 5.5
Questions
1. What is a coefficient? _______________________________________________
2. What is a character? ________________________________________________
3. What is a superscript? _______________________________________________
Part B – ADVANCED QUANTUM ELECTRON MODEL
Target 7 – Define the 2 methods for describing electron orbitals. A. Since electrons are difficult to keep track of, 2 different systems for describing their locations have
been developed.
1. Electron configurations - notation used to explain the arrangement of electrons in 3-D
2. Orbital diagrams – notation used to explain the arrangement and spin of electrons
Target 8 – Define the 3 rules for writing electron configurations and orbital
diagrams. A. There are 3 rules for writing electron configurations and orbital diagrams. Pg 133
1. Aufbau principle – Electrons occupy the orbitals of lowest energy first.
2. Pauli exclusion principle – Only 2 electrons may
occupy a single orbital at one time. This is only
possible if the 2 electrons have opposite spins***
3. Hund’s rule – electrons will enter each orbital 1 at a time until each orbital contains 1
electron. Only then can a second electron enter the same orbital.
***spin – electrons not only revolve around the nucleus, but they spin on an axis similar to the earth spinning as
it revolves around the sun. Opposite spin just means that 2 electrons will spin in opposite directions (clockwise
and counter-clockwise) pg 134
Target 9 - Write electron configurations and use shortcuts.
Visit these websites for more practice:
These don’t work anymore – look for new ones.
http://intro.chem.okstate.edu/WorkshopFolder/Electronconfnew.html
http://www.chemcollective.org/applets/pertable.php
Complete the chart - pg 133
Element Electron configuration Short cut Electron Configuration
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Target 10 - Write electron orbital diagrams Element Electron configuration Orbital Diagrams
H
1s1
He 1s2
Li
1s2 2s1
Be 1s2 2s2
B
1s2 2s2 2p1
C 1s2 2s2 2p2
N
1s2 2s2 2p3
O 1s2 2s2 2p4
F
1s2 2s2 2p5
Ne 1s2 2s2 2p6
Na
1s2 2s2 2p6 3s1
Mg 1s2 2s2 2p6 3s2
Al 1s2 2s2 2p6 3s23p1
Si 1s2 2s2 2p6 3s23p2
P 1s2 2s2 2p6 3s23p3
S 1s2 2s2 2p6 3s23p4
Cl 1s2 2s2 2p6 3s23p5
Ar
1s2 2s2 2p6 3s23p6
K 1s2 2s2 2p6 3s23p64s1
Ca 1s2 2s2 2p6 3s23p64s2
Sc 1s2 2s2 2p6 3s23p64s23d1
Ti 1s2 2s2 2p6 3s23p64s23d2
V 1s2 2s2 2p6 3s23p64s23d3
Cr 1s2 2s2 2p6 3s23p64s23d4
Mn 1s2 2s2 2p6 3s23p64s23d5
Fe 1s2 2s2 2p6 3s23p64s23d6
Target 11 - Write the arrow diagram for electron structure.
A. There are 2 models for the diagram, we will use the model on the left; you
should also be aware of the model to the right.
Target 12 - Identify s, p, d, and f blocks on the periodic table.
Target 13 - Explain why the f block is located below the d block on a
traditional periodic table.
Target 14 - Compare the quantum model of electrons to the classical model of
the electrons.
Summary
Electrons occupy a large amount of space around the nucleus of an atom. Electrons are organized
in energy levels and orbitals (where the electrons are located). Since atoms are 3 dimensional, we must
account for all space around the nucleus. When we bring in 3-D, the locations of electrons takes on a
shape – these shapes have names (s, p, d, f). To help keep track of all of the electrons, we write out
electron configurations and orbital diagrams.
Target 15 - Describe electrons in ground state compared to excited state.
1. So far, we have been talking about electrons around the nucleus that are highly organized.
2. When energy is added to atoms such as electricity or heat, the electrons will jump to a higher energy
level.
3. When this happens, all bets are off and the organization of the electrons becomes enormously
complex and is not part of this course.
4. When this happens, we say that the electrons are in an EXCITED STATE.
5. Electrons will NOT stay in excited state for long and will fall back to GROUND STATE.
6. Ground state describes electrons when they are in their normal organized positions.
Notes box – ground state and excited state
Questions
1. What is meant by ground state? _____________________________________
2. What is meant by excited state? _____________________________________
Target 16 - Explain what causes light (and the different colors of light)
a. Light is a form of energy that is released from atoms when electrons fall from excited state to
ground state
b. Right now in the lights in this room, electricity is forcing electrons to the excited state.
c.When the electrons fall back to ground state, the light is emitted which enables you to see.
d. Different atoms will emit different colors of light.
e. When we see things of different color, we are seeing the different forms of electron light
emissions from different elements.
f. This is how we know what our sun is made of and objects in space such as stars.
Use this later for a practice sheet.