Catalyst 12/19/12
1. An electron jumps from energy level 1 to
energy level 2. Energy is _________
(absorbed or released).
2. How many valence electrons does a
neutral Arsenic atom have?
3. *Honors: Predict what the electron
configuration of an excited sodium atom
might look like.
Agenda 12/19/12
• Catalyst
• Announcements
o Exam#3 on Thursday, 12/20/12
o Packet#4 DUE Thursday, 12/20/12
o HW: 1) Finish all unanswered packet
questions 2) Pages 125 – 126, #26 – 41, DUE
FRIDAY, 12/21/12 (Honors: Complete all
questions on pages 124 – 127; DUE January
5th.).
• Quantum Numbers*/Unit#4 Review
• Unit#4 Review – Around the World Bingo
Your class can earn class
points if:
everyone in class:
 Comes to class quietly
and on time
 Stays focused and on
task during class
 Leaves classroom neat
and organized
 Students are teaching
other students
 Majority of class
participates
 Follows all classroom
expectations and
procedures
Class Points
P3: 28 pts
(focused, neat
room)
P4: 31 pts (on
time, on task)
P6: 36 pts (on
time, neat room)
Objective
We will be able to list the four quantum numbers
and explain their significance.
Quantum Numbers
Quantum Numbers
• Currently, chemists and physicists accept the
quantum model of the atom. The Heisenberg
uncertainty principle and the Schroedinger
wave equation laid the foundation for modern
quantum theory. Quantum theory describes
mathematically the wave properties of
electrons and other very small particles.
Quantum Numbers
• Quantum numbers specify the properties
of atomic orbitals and the properties of
electrons in orbitals.
• Electrons are found in orbitals according
to quantum theory.
Quantum Numbers
• There are four quantum numbers that describe the
properties of atomic orbitals and the electrons inside
of them
• Think of them as an electron’s “address”
• The numbers are:
1. Principal Quantum Number
2. Angular Momentum Quantum Number
3. Magnetic Quantum Number
4. Spin Quantum Number
1. Principal Quantum
Number
• Tells you the MAIN ENERGY LEVEL an
electron is in
• Symbol is n
• Values for n are integers (whole
numbers) like 1, 2, 3, etc. N CANNOT be
zero.
• As n increases, the energy of an
electron increases.
Quick Review: Bohr
Model of the Atom
• Energy Level 1 = 2
electrons
• Energy Level 2 = 8
electrons
• Energy Level 3 = 18
electrons
• Energy Level 4 = 32
electrons
N values
2. Angular Momentum (or
Azimuthal) Quantum Number
• Tells you the SHAPE OF THE ORBITAL.
• Symbol is l
• Angular momentum quantum number
can have values from 0 to n-1.
(Remember n is your principal quantum
number.)
o Ex: If your n value is 3, your l values
are 0, 1, 2 because 3 -1 = 2.
o Ex: If your n value is 5, your l values
are 0,1,2,3,4
angular momentum
quantum number tells you
what shape it has
Orbital Shapes
Angular Momentum
Value (l)
Letter
shape
0
s
sphere
1
p
Dumbbell shape
2
d
clover shape
3
f
complex
COPY THIS.
3. Magnetic Quantum
Number
• Tells you the orientation of an orbital
around the nucleus
• Symbol is ml (fix this in your worksheet)
• the Magnetic Quantum Number has
values of –l to +l including zero.
o For example, if l = 3, my m values
are -3, -2, -1, 0, 1, 2, 3.
4. Spin Quantum Number
• Indicates the “spins states” of an
electron in an orbital
• Symbol ms
• Can have two values: +1/2, -1/2
When you put them all
together…
• The quantum numbers are written in this
exact order:
• (n, l, ml, ms)
During Classwork Time
1. Stay focused on the assignments you are
given.
2. Do the questions INDEPENDENTLY (on your
own).
3. Keep the noise level down.
4. Ask THREE before you ask ME.
5. You may put earphones on and listen to
music quietly as you do your work.
6. You must finish a certain number of questions
(depends on the person) by the end of the
period.
DO NOT FORGET YOUR STAMPS! You cannot get them once you
leave the class.
Objective 12/18/12
We will be able to determine the number of inner shell and
outer shell electrons by looking at the electron
configuration of an atom.
 
Open up the .pdf file
uploaded on Edmodo.
• Open the file in Notability.
• Follow along and take notes.
Outer Shell/Valence
Electrons
• Valence electrons or outer shell electrons
are found in the outermost region of the
atom. These are the electrons that
participate in chemical reactions and
chemical bonding.
Valence Electrons
Example#1:
• An atom with the following electron
configuration: 1s22s22p6 has _______
valence electrons.
Valence Electrons
• Example#2:
An atom with the following electron configuration:
1s22s22p63s23p4 has ________ valence electrons.
Inner Shell Electrons
• Inner shell electrons are found in the
innermost parts of the atom. All electrons
that are NOT valence electrons are
considered to be inner shell electrons.
Inner Shell Electrons
Example#1:
An atom with the following electron
configuration: 1s22s22p6 has _______ inner shell
electrons.
Example#2:
An atom with the following electron
configuration: 1s22s22p63s23p4 has ________
inner shell electrons.
3 Different Ways of Showing
Electron Configuration
Orbital
Notation
Electron
Configuration
Notation
1s22s22p5
Noble Gas
Notation
[He]2p5
When writing the electron
configuration…
1. Remember the THREE RULES (Aufbau,
Pauli Exclusion, and Hund’s)
2. Number of orbitals per subshell*
•
•
•
•
S subshells have 1 orbital
p subshells have 3 orbitals
d subshells have 5 orbitals
f subshells have 7 orbitals
3. Look up the number of electrons on the
Periodic Table
4. Only TWO electrons per orbital
Rules Governing Electron
Configuration
1. Aufbau Principle: ELECTRONS FILL LOWEST
ENERGY LEVEL FIRST
2. Pauli Exclusion Principle: ONLY TWO
ELECTRONS PER ORBITAL WITH OPPOSITE SPINS
3. Hund’s Rule: (ONLY for P, D, F orbitals):
ELECTRONS FILL ORBITALS ONE AT A TIME
BEFORE PAIRING UP
Order of energy shells
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p
INCREASING ENERGY
Electron Configuration
Exceptions…
Copper: 1s22s22p63s23p64s13d10
Chromium: 1s22s22p63s23p64s13d5
Why?
-Half-filled d orbitals are more stable
-Fully filled d orbitals are more stable
Around the Room Bingo
• All students must participate to receive credit for
today’s review
• Open the Around the Room Bingo.pdf file uploaded
on Edmodo in Notability.
• Go around the room and answer whichever questions
you’d like to try first.
• The first three people to get the correct answers
across, diagonally, or vertically, will receive 5 points
extra credit on tomorrow’s exam.
• If you complete all the questions, you will receive 3
points extra credit.
• Email all .pdf files to gutierrezbr@elizabeth.k12.nj.us
• Copying someone else = zero for the day