5.6 Ionic
compounds
Making ionic compounds
 Metal + Non-metal
 Made up of positive and negative ions
 Cations and anions attract each other to form ionic compounds
 The non-metal atom takes electrons from the metal atom
 To form a compound, the correct ratio of positive and negative ions
is required that makes the overall compound neutral
 Example: Sodium chloride (table salt) is an ionic compound made
up of sodium ions (Na+) and chloride ions (Cl -)
Na
Cl
[Na]+ [ Cl ]-
Ionic bond
 Attraction that holds oppositely charged ions
together in a compound
 Ionic compounds are those held together by
ionic bonds
 When ionic compounds are placed in water
they dissolve
 Solutions that contain dissolved ions are
good conductors of electricity
Practice: Ionic bonding
 1. Mg and Cl
 2. Al and O
 3. Na and P
5.7 Names and
Formulas of Ionic
Compounds
Naming ionic compounds
1. Write the name of the metal first, then
the name of the non-metal
2. Change the ending of the second element
to ‘–ide’
“-ide’ indicates a binary compound (only 2
different types of elements form the
compound)
Example:
NaCl is named sodium chloride
Practice:
1. AlCl3
______________
2. Na2O
______________
3. K2S
______________
4. CaBr2
______________
5. KCl
______________
Writing chemical
formulas for ionic
compounds
1. Write the symbols for each element in the
correct order (metal first, non-metal
second)
2. Add the ionic charge of each ion above
the symbol
3. Cross-over the ionic charge – this
balances the charge
4. Simplify if necessary
Example: magnesium oxide is MgO
Practice:
1. lithium fluoride
______________
2. sodium oxide
______________
3. calcium sulfide
______________
4. aluminum oxide
______________
5. calcium chloride
______________
Elements with multiple
ionic charges
 Some metals have more than one ionic charge
so they need a ROMAN NUMERAL in their
name to differentiate which ionic charge is used.
 For



example
Copper forms ions with a + and 2+ charge
Cu+ + Cl-  CuCl
Cu2+ + Cl-  CuCl2
 These ions are named like other cations, except
that Roman numerals in rounded brackets are
used to indicate ionic charge of the metal.
 Example: Cu+ ion is called copper(I) ion
Cu2+ ion is called copper(II) ion
Examples of Elements
with multiple ionic
charges
Metal
Chemical Symbols
of Ions
Names of ions
Copper
Cu+
Cu2+
copper(I)
copper(II)
Iron
Fe2+
Fe3+
iron(II)
Iron(III)
Lead
Pb2+
Pb4+
lead(II)
lead(IV)
Manganese
Mn2+
Mn4+
manganese(II)
manganese(IV)
Tin
Sn2+
Sn4+
tin(II)
tin(IV)
Practice:
Write the formulas for the following compounds:
1. copper(I) chloride
______________
2. copper(II) chloride ______________
3. iron(II) oxide
______________
4. tin(IV) sulfide
______________
5. tin(II) bromide
______________
Practice:
Name the following compounds:
1. CuO
______________
2. SnBr4
______________
3. FeO
______________
4. PbCl2
______________
5. MnO2
______________