NOMENCLATURE
Binary Molecular Compounds
Periodic Table
Ionic Vs. Covalent
• Ionic
• Metal/nonmetal
• Large differences in
EN (>1.7)
• Transfer electrons
• Results in cations and
anions
• Follows octet rule
• Covalent (Molecular)
• Nonmetals only
• EN differences <1.7
• Share electrons
• No ions are formed,
but sharing might not
be equal all the time
• Follows octet rule
Activity
Binary Molecular Compound
Binary Ionic Compound
SO3
Al2O3
N2F2
CaF2
NaCl
S2Cl2
Prefix Chart
mono
1
di
2
tri
3
tetra
4
penta
5
hexa
6
hepta
7
octa
8
nona
9
deca
10
Naming from the formula
 Write the name of the first element.
 Write the name of the second element.
 Change the ending of the second element to
"IDE"
Put the correct prefix in front of each element
to tell how many atoms of that element are in
the molecule.
oxide
Carbon diOxygen
Naming from the Formula
• Only use “mono” for the second element
• “ide” still only used for second element
• CO2 = carbon dioxide; NOT
monocarbon dioxide.
• H2O = dihydrogen monoxide
Try it
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SO2
NH3
N2H4
CCl4
NO
Naming the formula from the name:
Dinitrogen monoxide
 Write the symbol of the first element.
 Write the symbol of the second element.
 Use the prefix in the name to acquire the
correct subscript.
dinitrogen monoxide
N
N2O
O
Try it
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Diarsenic trioxide
Phosphorus trichloride
Sulfur dibromide
Chlorine trifluoride
Carbon monoxide
Assessment
1.
Name the compound CCl4
2.
Name the compound CO
3.
Write the formula for tetraphosphorus
decaoxide
4.
Write the formula for sulphur trioxide