D
o
o
r
2A Seating Chart
W
i
n
d
o
w
s
Lydia
Desiree
Taylor
Kendra
Emily
Mya
Jordan
Destiny
Brooke
Ashley
Lauren
Jake
Rachael
Jackie
Drew
Allie
Ben
Tabitha
Colleen
Chris
Stephanie
Krits
Austin
Paityn
Connor
Megan
Front of Room
D
o
o
r
1B Seating Chart
W
i
n
d
o
w
s
Kelsey
Sydney
Andy
Emily
Morgon
Krysta
Rachel M.
Rachel D.
Kyle
Allie
Hunter
Michael
Whitney
Mason
Ashley
Autumn
Christian
Alyssa
Phoenix
Front of Room
D
o
o
r
3B Seating Chart
W
i
n
d
o
w
s
Kaitlyn
Allysa
Danika
Tom
Michelle
Adam
RJ
Alexandra
Noah
Eryn
Holly
Dylan
Molly
Justin
Shelby
Kellie
Merik
Kenzie
Hunter
Front of Room
Friday, Jan. 10th: “A” Day
Monday, Jan. 13th: “B” Day
Agenda
 Collect movie worksheet
 Begin Chapter 5: “Ions and Ionic Compounds”
 Sec. 5.1: “Simple Ions”
Octet rule, ion, cation, anion
 In-Class: Section 5.1 review, pg. 165: #1-13
 Homework:
“Ions and Subatomic Particles” worksheet
 Concept Review: “Simple Ions”
Next time:
Quiz over section 5.1
Chemical Reactivity
How much an element reacts depends on its
electron configuration.
Noble gases are the least reactive elements
because their outer energy levels are full with 8
electrons. (except He, which is full with 2)
In most chemical reactions, atoms try to match
the electron configurations of the noble gases by
either gaining or losing electrons.
Most atoms want to become “noble”.
Chemical Reactivity
Octet Rule: a concept of chemical bonding
theory that is based on the assumption that
atoms tend to have either empty valence
shells or full valence shells of eight electrons.
“8 is Great!”
*Alkali Metals and Halogens are the
Most Reactive Elements*
As members of Group 1, alkali metals have only 1
electron in their outermost energy level.
By losing that 1 electron, an alkali metal can get
an electron configuration like a noble gas, with 8
electrons in its outermost energy level.
- 1 electron
1s22s22p63s23p64s1
1s22s22p63s23p6
Which alkali metal is this?
Potassium (K)
*Alkali Metals and Halogens are the
Most Reactive Elements*
Remember, potassium’s electron configuration
was:
1s22s22p63s23p64s1
Question: Why doesn’t potassium gain 7
electrons to achieve a stable octet instead of
losing 1?
Answer: Removing 1 electron requires
far less energy than adding 7 electrons.
Alkali Metals and Halogens are the
Most Reactive Elements
As members of Group 17, the halogens have 7
electrons in their outermost energy level.
By gaining 1 electron, a halogen can get an
electron configuration like a noble gas, with 8
electrons in its outermost energy level.
+ 1 electron
1s22s22p63s23p5
1s22s22p63s23p6
Which halogen is this?
Chlorine (Cl)
Valence Electrons
After it loses one electron, potassium has the
same electron configuration as chlorine does
after it gains one electron.
Both are the same as the noble gas argon.
1s22s22p63s23p6
The atoms of many elements become stable
by achieving the electron configuration of a
noble gas.
Remember, the electrons in the outermost
energy level are called valence electrons.
The Periodic Table Reveals an Atom’s
Number of Valence Electrons
To find out how many valence electrons an atom
has, check the periodic table.
Magnesium, Mg, has the shorthand electron
configuration:
[Ne]3s2
The outermost energy level is the 3rd energy level.
This means that a magnesium atom has two
valence electrons, located in the 3s orbital.
The Periodic Table Reveals an Atom’s
Number of Valence Electrons
The shorthand electron configuration of
phosphorus, P, is:
[Ne]3s23p3
The outermost energy level is the 3rd energy level.
This means that each phosphorus atom has five
valence electrons: two in the 3s orbital and three
in the 3p orbital.
Atoms Gain or Lose Electrons to Form
Stable Ions
All atoms are uncharged because they have
equal numbers of protons and electrons.
For example, a potassium atom has 19
protons and 19 electrons.
After losing one electron, potassium still has
19 protons but now only has 18 electrons.
Because the numbers are not the same, there
is a net electrical charge.
Atoms Gain Or Lose Electrons to Form
Stable Ions
Ion: an atom, radical, or molecule that has
gained or lost one or more electrons and has a
negative or positive charge.
The following equation shows how a
potassium atom forms an ion with a 1+ charge.
K  K+ + e
Cation: an ion that has a positive charge.
Atoms Gain Or Lose Electrons to Form
Stable Ions
In the case of chlorine, far less energy is
required for an atom to gain one electron
rather than lose its seven valence electrons to
become stable.
The following equation shows how a chlorine
atom forms an ion with a 1− charge.
Cl + e → Cl
Anion: an ion that has a negative charge
Characteristics of Stable Ions
Both an atom and its ion have the same
number of protons and neutrons, so the nuclei
are the same.
But, an atom and its ion have
different numbers of electrons.
The chemical properties of an
atom depend on the number
and configuration of its electrons.
So, an atom and its ion have different
chemical properties.
Many Stable Ions Have Noble-Gas
Configurations (pg. 162)
Some Stable Ions Do Not Have
Noble Gas Configurations
Transition metals often form ions without
complete octets.
The stable transition metal ions are all cations.
Some elements, mostly transition metals, can
form several stable ions that have different
charges…
Some Stable Ions Do Not Have
Noble Gas Configurations (pg. 163)
**Metals Form Cations**
Nearly all metals form cations, which means
they lose electrons. For example, magnesium
metal, Mg, has the electron configuration:
1s22s22p63s2
To achieve a noble-gas configuration,
magnesium must lose two electrons.
Losing two electrons requires less energy than
gaining six.
Atoms are lazy,
just like us!
**Non-metals Form Anions**
The atoms of all non-metal elements form
anions, which means they gain electrons. For
example, oxygen, O, has the electron
configuration
1s22s22p4
To achieve a noble-gas configuration, oxygen
must gain two electrons.
Acquiring two electrons requires
less energy than losing six.
In-Class/Homework
In-Class:
Section 5.1 review, pg. 165: #1-13
Homework:
“Ions and Subatomic Particles” WS
Concept Review: “Simple Ions”
Next time:
Quiz over Section 5.1
D
o
o
r
4A Seating Chart
W
i
n
d
o
w
s
Abby
Daleah
Sarah
Korey
Eric
Ashley
Mason
Rebecca
Brooklyn
Cody
Anna
Tate
Troy
Jordan
Josh
Morgan
Front of Room