NOMENCLATURE
IONIC BONDING
Thursday - Day 3 Notes
Click the link below to watch the video:
VIDEO CLIP ON HOW
ATOMS BOND: IONIC
COMPOUNDS
http://www.nbclearn.com/portal/site/learn/chemistry
-now/how-atoms-bond
Quick Review

_Ions_____ - atoms that have lost or gained one or
more electrons.
__cation___ – positively charged ion
 _____anion___ – negatively charged ion
 The charge on the ion is known as the ___oxidation
number____


__Polyatomic ion____ – ion consisting of two or
more atoms
+
2+
3+ 4-+ 3- 2- 1-
0
Practice - write the ion with the charge for the following
elements
* Li
+
* Be
* Al
* Na
*F-
2+
3+
+
2+
* Ca
* Si
+-4
* H
* K
+
+
2-
* O 2-
* Fr +
* N 3-
* Cl -
* P
*S
3-
NOTES #2: Binary Ionic Chemical Names
and Formulas



Ionic bonds are formed between a
metal and a nonmetal OR
cation + anion.
The bond involves the transfer of electrons from the
metal to the nonmetal.
 The electron is transferred from the cation to the
anion so that both atoms have a complete valence
shell (usually 8 electrons in valance).
The overall charge of ionic compounds must equal
zero.
Naming
Ionic Compounds
* First
name the cation and then the anion.
(metal)
(nonmetal)
* Change the ending of the anion to –ide.
Example:
•MgCl2
magnesium chloride
•Li2S
Lithium sulfide
_________________________
Magnesium
oxide
MgO _________________________
K3P
Potassium
phosphide
________________________
CsCl
________________________
Ba3N2
Cesium chloride
Barium nitride
________________________
Practice
DRAWING Lewis Dot Structures for Ionic Compounds
•
•
The overall charge on the compound must equal zero, that is, the number of
electrons lost by one atom must equal the number of electrons gained by the
other atom.
The Lewis Structure (electron dot diagram) of each ion is used to construct the
Lewis Structure (electron dot diagram) for the ionic compound.
The Lewis Dot structures show the location of the valence
electrons after the electrons have been transferred.
Examples: Lithium fluoride
•
Lithium atom loses one electron to form the cation Li+
•
Fluorine atom gains one electron to form the anion F•
Lithium fluoride compound can be represented as
Remember the Octet rule….
DRAWING Lewis Dot Structures for Ionic Compounds
Draw the Lewis structure of Lithium oxide.
formula for this compound?
What would be the chemical
Writing Formulas for Binary
Ionic Compounds
Balance
 When given two ions, __________________
the charges and make them the
subscripts
___________________.
 Do NOT keep the +/- signs
 _______________
Reduce subscripts if possible
This means we must reduce the subscripts if they have a common
denominator.
Example: Ca4F8
CaF2
Writing Formulas for Binary
Ionic Compounds
A. Using Balanced charges Method:
B. Using the Crisscross method:
**Sum of charges must equal zero.
Ex:
a. Na+1 + Cl-1  NaCl
 Example: Li+1 O-2
(+1 + -1 = 0)
b. Mg+2 + O-2  MgO * (+2 + -2 = 0)
* Don’t write this Mg2O2 because it must be
reduced.
Now, let’s use the name to write the chemical formula
Name

Lithium oxide
cation
anion
Li+1
O-2
_______ _______
Li+1
formula
Li2O
_____________
Lewis Dot Structure
Important Facts about Ionic Compounds
• We use subscripts to represent the
number of each ion.
Al2O3
2 Aluminum Ions and 3 Oxide Ions
For example 2…Change it from Magnesium sulfide to Magnesium phosphide
A. Using Balanced charges Method:
Mg2+
Mg2+
Mg2+
6+
and
B. Using the Crisscross method:
Mg2+
P3P3=0
6-
Name
cation

Mg
______
Magnesium phosphide
Mg 3
2+
anion
formula
Mg3P2
P
_______
____________
3-
and
P3S2
Lewis Dot Structure
Homework: Page 9


For added help: watch this video
And use your periodic table!!!!
Notes 3: Binary Ionic Compounds with
Transition Metals (Multivalent cations)

Multivalent Cations are found mostly in
the group B elements. (the middle of
the periodic table)
These elements are also known as the Transition metals.
Roman
Charge
Numeral
If your cation is a transition metal,
then you must specify the charge
with a Roman numeral.
Example: Iron (III) Sulfide
Just like the compounds we looked at
yesterday, the sum of charges must
equal zero . and we can still use the
Criss-cross method when writing the
chemical formula.
I
II
III
IV
V
VI
VII
VIII
+1
+2
+3
+4
+5
+6
+7
+8
Writing & Naming Formulas
with Roman Numerals Practice
Cu+
S2-
Cu2S
Mn2+
O 2-
MnO
Sn4+
F-
SnF4
Lead II iodide
Pb2+
I-
Iron III oxide
Fe3+
O2-
Lead IV oxide
Pb4+
Cobalt III phosphide
Co3+
P3-
Naming Ionic Compounds with
Roman Numerals

If there is a transition metal (B
group element) present in the
formula, you will need to include a
roman numeral when you name the
compound.
So, which metals DO NOT require a
roman numeral?
3+
2+
2+ and Ag+
 Al , Zn , Cd

Writing Multivalent Compounds
HOMEWORK

Complete page 11
REMEMBER:
How can you determine the charge or roman
numeral?
You will have to work backwards.
And
Roman Numeral = Charge of the Metal
Polyatomic Ions

A polyatomic ion are groups of
atoms that behave as one unit.



They are treated like single ions in formulas, but use parenthesis
when more than one is used in a formula.
NEVER change name or look of polyatomic. If you change the
subscripts for any part of the polyatomic, then it is no longer that
same polyatomic ion.
Otherwise….use all the same rules for naming and writing
compounds as with any other Binary Ionic compound.
EX:
NH4+ is not the same as NH+
CO32- is not the same as CO22- or CO2-
Naming Ionic Compounds with
Polyatomic Ions


When you name a compound with a
polyatomic ion, the polyatomic ion
keeps its name.
It is easy to identify a compound
with a polyatomic ion because it
will have more than 2 elements
(more than 2 capital letters).
Polyatomic Ion Practice
Formula
Al+3
CO3 -2
Al2(CO3)3
Ca+2
NO3 -1
Ca(NO3)2
K+1
ClO3 -1
KClO3
Name
Aluminum carbonate
Calcium nitrate
Potassium chlorate
Question: How would potassium chlorite be different?
K+1
ClO2 -1
KClO2
Name the following compounds
Ba(OH)2
Change CaSO4 to Cu
Barium hydroxide
CuSO4
Copper II sulfate
(NH4)3P
Ammonium phosphide
Write the formula for the following
compounds:
cation
anion
Strontium phosphate
2+
Sr
________
3PO
4
_________
Lithium acetate
+
Li
________
C
H
O
2
3
2
_________
Sodium sulfate
Na
_________
+
2-
S04
_________
formula
Sr3(PO4)2
______________
LiC2H3O2
______________
Na2S04
______________
Homework: Complete page 13
Keys to Success

Before naming ANY compound,
Identify
the type of compound.
Molecular?
If
Ionic? Acid?
it is molecular, remember to use your
prefixes.
If it is ionic, ask yourself.
Does
the metal need a roman numeral?
Does it contain a polyatomic ion?
If
it is an acid, which pattern does it
follow?
PUZZLE PIECE ACTIVITY ON WRITING
FORMULAS FOR IONIC COMPOUNDS
•Work in pairs to assemble the various compounds.
•Let’s try the first one together.
•What is the compound formed between Mg and F?
Mg2+
Magnesium
Metal
Mg
Metal’s
Charge
+2
Ffluoride
Ffluoride
Nonmetal’s
Nonmetal
Charge
F
-1
A perfectly assembled
compound should be a
square or a rectangle.
Picture of
Puzzle
Pieces
Formula
Name
MgF2
magnesium
fluoride
Sum of
Charges
0