Catalyst – March 24x4/6/4, 2010
LAB HOMEWORK OUT PLEASE!
How many electrons will the following atoms
need to gain or lose to be stable?? Be sure
to directly answer the question.
1. Na
2. Cl
3. Pb
4. Xe
5. Ca
Today’s Objectives
SWBAT show the formation of
ionic bonds.
 SWBAT write formulas for
balanced ionic compounds.
 SWBAT name ionic compounds.

Today’s Agenda
Catalyst
 Lab Results and Review
 Writing Ionic Formulas!
 Naming Ionic Compounds!
 Practice!
 Exit Question
Homework: Bond/Formula Worksheet!
Study for Quiz 3.1!

Higher
rd
3
IE – B or Ca?
Higher
st
1
IE – F or Mg?
F
Mg
Test Prep Review

Which general trend is demonstrated by the
Group 17 elements as they are considered in
order from top to bottom on the Periodic
Table?
 (1)
a decrease in atomic radius
 (2) a decrease in electronegativity
 (3) an increase in first ionization energy
 (4) an increase in nonmetallic behavior
Test Prep Review

An atom of aluminum in the ground state and
an atom of gallium in the ground state have
the same
 (1)
mass
 (2) electronegativity
 (3) total number of protons
 (4) total number of valence electrons
Let’s think about this…

What does lithium do to become stable?

What does chlorine do to become stable?

How do they come together???
Let’s think about this…

What does beryllium do to become stable?

What does oxygen do to become stable?

How do they come together???
Let’s think about this…

What does beryllium do to become stable?

What does chlorine do to become stable?

How do they come together???
Alright…
That process takes a long
time…scientists aren’t going to do it
every single time
 WE HAVE A SHORCUT TO FIND WHAT
IONIC COMPOUND WILL FORM!
 Get ready for it…

Kris Kross Method!
2+
3Ca As
Ca3As2
Key Point #1: To write ionic formulas,
write down the stable ions and cross
the oxidation numbers (charges) to
make them subscripts
1+
1Na Cl
1+
2Li O
NaCl
Li2O
Use the charges:
Group
1
2
3 4 5 6 7 8
Charge
1+ 2+ 3+ 4- 3- 2- 1- 0
The two ionic charges must
balance to ZERO!!!
Or use the ionic cheat
sheet to find the charges.
Remember! The two ionic
charges must balance to
ZERO!!!
Kris Kross Method!
2+
3Ca As
Ca3As2
Which charge
ALWAYS
comes first?
POSITIVE!!!
Which type of
element ALWAYS
comes first?
METAL!!!
K F
Ba N
Ga O
Ca Cl
K Si
Co I
1+
1K F
Ba N
Ga O
Ca Cl
K Si
Co I
KF
Ba N
Ga O
Ca Cl
K Si
Co I
KF
2+
3Ba N
Ga O
Ca Cl
K Si
Co I
KF
Ba3N2
Ga O
Ca Cl
K Si
Co I
KF
Ba3N2
3+
2Ga O
Ca Cl
K Si
Co I
KF
Ba3N2
Ga2O3
Ca Cl
K Si
Co I
KF
Ba3N2
Ga2O3
2+
1Ca Cl
K Si
Co I
KF
Ba3N2
Ga2O3
CaCl2
K Si
Co I
KF
Ba3N2
Ga2O3
CaCl2
1+
4K Si
Co I
KF
Ba3N2
Ga2O3
CaCl2
K4Si
Co I
K F
Ba N
Ga O
Ca Cl
K Si
Co I
You don’t know about transition
metals! So.. the problem must tell you
the number of electrons. Cobalt (II)
means that Cobalt gives up 2
electrons
K F
Ba N
Ga O
Ca Cl
K Si
2+
1Co I
K F
Ba N
Ga O
Ca Cl
K Si
CoI2
Polyatomics
3-
3-
1 Phosphate Ion
2 Phosphate Ions
PO4
(PO4)2
Calcium Phosphate
2+
Ca
3PO4
63-
Ca2+
Ca2+
Ca2+
6+
3-
For POLYATOMICS it gets
a bit more complex
4+
2Pb SO4
1+
3NH4 PO4
Pb2(SO4)4
(NH4)3 PO4
You have a little memorizing to do…
You have to memorize the
formula and charges for these
polyatomic ions for the test…


And life
Naming Ionic Compounds
Formula for
Ionic Compound
Name for
Ionic Compound
NaCl
Sodium chloride
CaCl2
Calcium chloride
KBr
Potassium bromide
MgF2
???
NaBr
???
Naming Ionic Compounds
Key Point #2: To name ionic compounds,
• Write name of first element
(metal).
• Second element ends in -ide.
• Ignore subscripts!
Naming Ionic Compounds
Draw a mental line
between the ions.
+
Na
Cl
Naming Ionic Compounds
Binary Ionic Compound –
an ionic compound
composed of two
elements
Naming Ionic Compounds
CaCl2
Naming Ionic Compounds
CaCl2
Calcium Chloride
Naming Ionic Compounds
Al2O3
Naming Ionic Compounds
Al2O3
Aluminum Oxide
Naming Ionic Compounds
ZnO
Naming Ionic Compounds
ZnO
Zinc (II) Oxide
Naming Ionic Compounds
BaCO3
Barium
Naming Ionic Compounds
If the first element is +2,
where should we find
the second?
(Remember, charges
must balance!)
Naming Ionic Compounds
BaCO3
Barium
Naming Ionic Compounds
BaCO3
Barium Carbonate
Naming Ionic Compounds
AlPO4
Naming Ionic Compounds
AlPO4
Aluminum
Naming Ionic Compounds
AlPO4
Aluminum Phosphate
Naming Ionic Compounds
H2SO4
Naming Ionic Compounds
FeSO4
Naming Ionic Compounds
FeSO4
What do we do about
transition metals??
Naming Ionic Compounds
FeSO4
Sulfate
Naming Ionic Compounds
FeSO4
Since Sulfate is -2, Fe
must be +2
Naming Ionic Compounds
FeSO4
Iron(II) Sulfate
Naming Ionic Compounds
FeSO4
Iron(II) Sulfate or
Ferrous Sulfate
Exit Ticket
Write the formulas and compound
names for the following elements.
1. Ga Cl
2. K
S
3. Mg PO4
Exit Question
1.
2.
What is the formula for ammonium
sulfate?
Write the formulas formed from the
following atoms/ions:
A) K O
B) Na Br
C) Mg S