3.2
All about ionic compounds !
Names and Chemical Formulas of
Ionic Compounds
Review of ionic compounds:
 They are between metals and non-metals
 They are between metals and polyatomic ions!
 They gain and lose electrons ( a transfer)
Ex: calcium bromide
 Today we will learn how to write the names and
formulas of ionic compounds 
Rules for writing names of
ionic compounds
Rules:
The (metal) positive ion is always the first part of the
name and its name does NOT change.
Calcium Calcium
The (non-metal) negative ion is always the second
part of the name and its name changes.
The non-metal ‘s name changes to the suffix/ending
“ide”
Bromine  Bromide
If the non-metal is a polyatomic ion, then write
its original name with no changes at all
e.g. Ca(NO3)2 calcium nitrate
Practice naming NON-METAL IONS
Take off the original ending and add an “ide”
ending.
Element Name
Ion Name
Florine (F) 
Sulphur (S) 
Write the names of the following ions:
a) Br- = __________________________
b) Cl- = __________________________
c) I- = __________________________
d) O-2 = __________________________
e) N-3 = __________________________
Write the names for the following ionic compounds:
NaCl
LiNO3
CaBr2
Ba3(PO4)2
MgO
KOH
Rules continued
How to write the CHEMICAL FORMULA for the ionic
compound????
We need to use the charges/combining capacity for
each ion when we do this.
So how does it work?
How to write chemical formulas of ionic compounds
Aluminum Chloride
Potassium Nitride
How to write chemical formulas of ionic compounds
Sodium phosphate
Magnesium oxide
How to write chemical formulas of ionic compounds
Iron(III) oxide
NAMING MONATOMIC METAL IONS
If a metal has more than one possible charge,
the charge has to be indicated by a Roman
numeral, in parenthesis, immediately following
the name.
Ex: Fe+3
Fe+2
Roman numerals are:
I
1
V
5
II 2
VI
6
III 3
VII 7
IV 4
VIII 8
IX
X
9
10
P. 86
P. 87
Back to multivalent metals
What is the name for
Fe2O3
MnO
Hg3N2
p. 89
p. 90
Practice naming with
polyatomic ions
Potassium chromate
CaSO4
p. 91
Homework
 Homework is to finish all the questions given in this
set of notes.
 You should be feeling a little Y Zr (wiser) after this
lecture.
Credit to Alexander the great and his gang