1. Naming Ions and Writing Formulas for Ionic Compounds

2. Monoatomic ions single atom with a charge
Cation - + charge from losing e-
Anion - - charge from gaining e-
Cations are the name of the element. For example:
Na+ sodium ion
Mg2+ magnesium ion
Anions change the ending to –ide. For example:
O2- oxide
Cl- chloride

3. Polyatomic ions composed of more than one atom
-1 Charge
Acetate CH3COO- or C2H3O2-
Nitrite NO2-
Nitrate NO3-
Cyanide CN-
Hydroxide OH-
Hypochlorite ClO-
Chlorite ClO2-
Chlorate ClO3-
Perchlorate ClO4-
-2 Charge
Sulfite SO32-
Sulfate SO42-
Carbonate CO32-
-3 Charge
Phosphate PO43-
+1 Charge
Ammonium NH4+

4. NAMING/WRITING BINARY IONIC COMPOUNDS
Binary – compound made of two kinds of elements
Examples: NaCl, MgBr2, FeI3

5. Writing the formulas
Cation (+) first
Anion (-) last
“criss-cross” method
Naming the formulas
Examples:
NaCl
sodium chloride
MgBr2
magnesium bromide
FeI3
iron iodide

6. NAMING/WRITING COMPOUNDS WITH POLYATOMIC IONS
Writing the formulas
Cation (+) first
Anion (-) last
“criss-cross” method
Naming the formulas
Examples:
NH4Cl
ammonium chloride
Ca(OH)2
calcium hydroxide
Na2SO4
sodium sulfate

7. Stock System using Roman numerals in nomenclature
Used for transition metals with more than one possible charge (there are others)
FOR EXAMPLE:
FeCl2 and FeCl3 are both iron chloride.
To differentiate, use the stock system:
FeCl2 = iron (II) chloride
FeCl3 = iron (III) chloride

8. Hinge Questions:
Write the names for these formulas.
CaI2
NiO
Al2S3