Science 10 Unit A: Chemistry
Part 2: Nomenclature
Nomenclature = Naming
Binary Ionic Compounds – are made up of one metal
and one non-metal ion. Electrons are exchanged
between ions.
Multivalent Ions – are metal ions
which can form different charges.
Polyatomic Ions (Complex Ions) – are
groups of ions bonded together acting
as a single ion. They are named in a
similar way as binary ionic
compounds.
In order to distinguish between the two
ions, we use roman numerals.
The polyatomic ions are listed on your
periodic table.
ex) Write the formula for iron (II) oxide.
To write the formula: write the metal ion symbol
first, then the non-metal ion symbol. Cross the
charges found on each ion.
ex) Al3+ + O2-  Al2O3
Tips:
- if the subscripts have a common factor,
divide by the common factor.
ex) Mg2+ + O2-  Mg2O2 MgO
Fe2+ + O2-  FeO
ex) Write the formula for iron (III) oxide.
Fe3+ + O2-  Fe2O3
Na+ + OH-  NaOH
When writing the name, we have to check
to see which charge was used to make the
compound.
Tip: If after crossing charges, there is a
new subscript behind the polyatomic
ion, the polyatomic ion must be
bracketed.
ex) Name CuCl2.
ex) Write the formula for aluminum
hydroxide.
To write the name: write the metal name first,
followed by the non-metal ion. Change the ending
on the non-metal to “ide”.
Step 1: “Uncross” the charges:
ex) K2S = potassium sulfide
Step 2: Write the name, including the
roman numeral.
CuCl2  Cu2+ + Cl-
Al3+ + OH-  Al(OH)3
ex) CaBr2 = calcium bromide.
Tips: the numbers don’t appear in the name (yet).
ex) Write the formula for sodium
hydroxide.
CuCl2 = copper (II) chloride
ex) What is the name of Mg(NO3)2?
Mg = magnesium NO3- = nitrate
magnesium nitrate
Practice: Nomenclature Assignment (pg 1-8)
Molecular Nomenclature
Molecules to Memorize
A molecular compound is made up of two or more
nonmetals bonded together. In this type of bond,
electrons are not exchanged, but shared between
atoms.
Latin and Greek prefixes are used to indicate the
number of atoms of each atom present in a molecule.
Acid Nomenclature
For now, we consider most compounds that dissolve in water and contain hydrogen an
acid. We deal with two types of acids in Science 10:
Binary Acids: consist of two elements, the first always hydrogen, the second a nonmetal ion. Binary acids end in “ide”.
Oxy acids: consist of two ions, the first always hydrogen, the second a polyatomic ion
containing oxygen. Oxy acids end in “ate” or “ite”.
ex) CO2 = carbon dioxide
Tip: we add an (aq) behind the acid to indicate it is aqueous, or soluble in water.
ex) P2O5 = diphosphorous pentaoxide
Use the chart to name acids:
ex) nitrogen dioxide = NO2
Tip: the mono is only used for the second element,
not for the first.
Tip: the suffix on the last element changes to “ide”.
Practice: to end of
Nomenclature Book.