Science 10: Chemical Reactions
NAMING
& MOLECULAR COMPOUNDS
Naming, Naming, Formula?!
 Why is this important?
IUPAC
 International Union of Pure and Applied
Chemistry (est. 1919)
 Developed the system you are learning to
ensure that each pure substance has a unique
name (systematic name)
 What are some advantages of this system?
Properties of Ionic
Compounds
 Metal & Non-Metal
 Atoms held together with ionic bonds
 One element gains electrons (anion)
 One elements loses electrons (cation)
 Form large, repeating, cubic lattice structures
Properties of Molecular
Compounds
 Usually two non-metals
 Atoms joined by covalent bonds to form
molecules
 Atoms share electrons like a “tug-of-war”
 Molecular compounds are made up of many
molecules attracted to one another
Naming Molecular Compounds
1. The first element in the name is usually the
one that is farther left on the periodic table.
2. The suffix “-ide” is attached to the name of
the second element
3. Prefixes are used to indicate the how many
of each type of atom are present in one
molecule (ex. mono-, di-, tri-)
4. Only use the prefix mono if it applies to the
second element in the name
Example
 How would we write the name of a
compound that is one part C and one part O?
 Answer: carbon monoxide
Example
 How would we write the name of a
compound that is two parts N and three parts
O?
 Answer: dinitrogen trioxide
Writing Formula for
Molecular Compounds
 Like in the name, the element that is farther
left on the periodic table is listed first in the
formula.
 Just like in the formula of ionic compounds,
the formula of molecular compounds are
written to show the ratio of one element to
another with subscripts
Example
 What is the formula for the compound
nitrogen tribromide?
 Answer:
NBr3
Example
 What is the formula for the compound
disulfur difluoride?
 Answer:
S2F2