Catalyst
1. The periodic table is arranged by what?
2. What is the number the arrow is point to
referred to as? What does it tell us?
End
Homework Review and Exit Slip Grading
Lecture 1.4 – Electron Configurations
and the Octet Rule
Build an Atom Simulator
Today’s Learning Target
• LT 1.4 – I can determine the number of
valence electrons for an element, draw a Bohr
electron configuration for an element and
explain how the Octet rule leads to the
formation of ions.
Essential Point
• Atoms do not have a charge
• Neutral atoms have equal numbers of protons
and electrons.
• So, atomic number also tells us the number of
electrons.
Periodic Table Nomenclature
• Groups – Vertical columns on the Periodic
Table
• Periods – Horizontal rows on the Periodic
Table
• Periods Push Across
• Groups Go Down
Bohr Model of the Atom
Electron Orbits
• The first orbit holds 2 electrons
• Every other orbit after the first orbit holds 8
electrons.
Valence Electrons
• Valence Electrons – The number of electrons
that are in the outermost electron orbit
Class Example
• Draw the Bohr electron configuration for
lithium. Determine the number of valence
electrons.
Table Talk
• Draw the Bohr electron configuration for
sodium. Determine the number of valence
electrons.
Stop and Jot
• Draw the Bohr electron configuration for
potassium. Determine the number of valence
electrons.
SHORTCUT!
• All elements in the same group (1A, 2A, etc.)
have the same number of valence electrons.
SUMMARIZE
Around the World
• There are 8 problems
posted around the room.
• You and your partner must
complete all 8 as a team.
• When completed, show to
Mr. Astor
• You must complete all 8
problems.
5 MINUTE BREAK
The Octet Rule
• Atoms like to have a full outer valence shell
• They will gain or lose electrons in order to
have an outer orbit with 8 electrons (or 2 if it
is the first energy level).
• They will gain/lose based on what is easiest.
Class Example
• Draw the Bohr electron configuration for
beryllium after it has satisfied the Octet Rule.
Table Talk
• Draw the Bohr electron configuration for
magnesium after it has satisfied the Octet
Rule.
Stop and Jot
• Draw the Bohr electron configuration for
calcium after it has satisfied the Octet Rule.
SHORTCUT!
• All elements in the same group, gain/lose the
same number of valence electrons.
Ions
• When atoms gain/lose electrons, they gain a
charge.
• Ion – An atom or molecule where the number
of protons does not equal the number of
electrons, giving the atom a charge.
• Cation – A positively charged ion
• Anion – A negatively charged ion
Cats make people feel positive
Class Example
• Determine the ion that forms for fluorine after
the Octet Rule has been satisfied.
Table Talk
• Determine the ion that forms for nitrogen
after the Octet Rule has been satisfied.
Stop and Jot
• Determine the ion that forms for oxygen after
the Octet Rule has been satisfied.
SHORTCUT!
• All elements in the same group, form ions
with the same charge.
SUMMARIZE
Rally Coach
1) Each of you will pair up with the person that is across
from you.
2) Pick who is Partner A and who is Partner B.
3) You will grab a whiteboard and a marker.
4) When I say go. Partner A will read the question aloud
to Partner B. Then, Partner A will walk Partner B
through the steps that need to be taken to get the
final answer. MAKE SURE TO DO ALL THE STEPS!
5) I will call time after 30 seconds and each pair will raise
their board in the air.
6) After I ask groups about your answers, the partners
switch roles and Partner B does the questioning and
reasoning and Partner A does the writing.
Question 1
• Draw the Bohr electron configuration for
Neon.
Question 2
• Draw the Bohr electron configuration for
Sulfur
Question 3
• Determine the number of electrons
Phosphorus would gain or lose to satisfy
the octet rule.
Question 4
• Determine the number of electrons
magnesium would gain or lose to satisfy
the octet rule.
Exit Ticket
1. Draw the Bohr structure for Phosphorus
2. How many electrons must it gain/lose to
satisfy the Octet Rule? What will the charge
of its ion be?
3. What is wrong with the drawing below?
Rate Yourself
• Based on the exit ticket and your current level of
understanding, rate yourself 1 – 4 on LT 1.1 - 1.4
Closing Time
• Homework 1.3 – Octet Rule and Bohr
Structures
• Quiz Wed on LTs 1.1 – 1.4