Nomenclature
Chemical Formula – type of notation made with
numbers and chemical symbols
– indicates the composition of a compound
– indicates the number of atoms in one molecule
Molecule - Bonded collection of two or more atoms
of the same element or different elements
- monatomic molecule – one atom molecules
- diatomic molecule – two atom molecules
(seven) MEMORIZE
Br, I, N, Cl, H, O, F
Nonmetals
METALS
Metals
Semi-metals
Location: Left side of Periodic Table
Properties:
Ductile – drawn into wires
Malleable – hammered into sheets
Metallic Luster – shine
Good Conductors of Heat and Electricity
Nonmetals
Location: Right side of Periodic Table
Properties:
Brittle
Lack Luster – not shiny
Poor Conductors of Heat and Electricity
Semi-metals
Location: Along Stair-step
Properties:
Have properties of metals and nonmetals
also called METALLOIDS Si, Ge, As, Sb, Te, Po, At
Naming
1. Ionic Compounds – Formed from a metal and a non-metal
When a metallic element combines chemically with a non-metallic
element to form an ionic compound one or more electrons are
transferred from each atom of the metal to one or more atoms of the
nonmetal
charged atom – ion
net charge on compound = 0
Na+1
+
Cl-1

NaCl
Loses
Gains
compound
electron
electron
NO CHARGE
Cation – positive ion – metal
Anion – negative ion - nonmetal
Ions Formed
0
+1
+3 ±4 -3 -2 -1
+2
varies
Rules for writing formulas for Ionic
Compounds
Binary compound – compound formed by two elements
Tertiary compound - compound formed by more than two elements
Polyatomic ion – groups of atoms of more than one element that carries a
charge
– bound tightly together
– don’t break apart during a chemical reaction, function as a unit
1. Write the symbols – cation first, anion second
2. Determine the charge on the atoms of each element
3. Select subscripts that make the lowest ratio
TOTAL POSITIVE CHARGE = TOTAL NEGATIVE CHARGE
– When using subscripts with polyatomic ions, the formula for the ion is
placed in parentheses and the subscript is placed outside the
parenthesis
+1
-2
+3
-2
+1
Na
O
Al
S
K
SO4-2
Examples:
Sodium Oxide
Aluminum Sulfide
Potassium Sulfate
Na2O
NH4+1
PO4-3
Ammonium Phosphate
Al2S3
(NH4)3PO4
K2SO4
Naming Ionic Compounds
Name the Cation first – Name of the metal
the anion is the name of the nonmetal altered by adding the suffix -ide to the root word
chlorine  chloride
fluorine  fluoride
sulfur  sulfide
oxygen  oxide
phosphorus  phosphide
etc…
Polyatomic name is not altered
Some metals can form more than one kind of ion (Type II)
Fe, Cu, Co, Sn, Pb, Hg …
Stock System – name the metal followed by a roman numeral in parenthesis. The
Roman numeral tells the charge.
I, II, III, IV, V, VI, …
Exception: Mercury (I) = Hg2+2
Examples:
NaCl = sodium chloride
KNO3 = potassium nitrate
MgBr2 = magnesium bromide
CuO = copper (II) oxide
Li2SO4 = lithium sulfate
Cu2O = copper (I) oxide
K3N = potassium nitride
SnS2 = tin (IV) sulfide
Molecular Compounds
2. Molecular Compounds (molecules) – compounds made from two nonmetals
- electrons are shared by two atoms
Naming Molecular
Prefixes: (MEMORIZE)
Mono-1
tetra-4
hepta-7
deca-10
di-2
penta-5
octa-8
tri-3
hexa-6
non-9
prefixes are used with both the first named and second named element. Exception:
mono- is not used on the first word
second word ends in –ide
If a two syllable prefix ends in a vowel, the vowel is dropped before the prefix is attached
to a word beginning with a vowel
monooxide
Writing molecular formulas
Translate prefixes
Examples:
N2O = Dinitrogen monoxide
dihydrogen monoxide = H2O
Si8O5 = Octasilicon pentoxide
tetrasulfur hexachloride = S4Cl6
NH3 = Nitrogen trihydride
carbon monoxide = CO
P3I10 = Triphosphorus deciodide
carbon dioxide = CO2
Naming Acids
Acid - has one or more H+1 ions attached to an anion Second Word is Acid
If the anion doesn’t contain oxygen, the acid is named with the prefix hydroand the suffix –ic attached to the root
When the anion contains oxygen, the suffix –ic or -ous is added
-ate becomes –ic
-ite becomes –ous
Writing formulas for acids
Balance charges between H+1 and anion.
Examples:
HCl = Hydrochloric acid
hydroiodic acid = HI
HClO3 = Chloric acid
hydronitric acid = H3N
HClO4 = Perchloric acid
nitric acid = HNO3
HClO2 = Chlorous acid
nitrous acid = HNO2
HClO = hypochlorous acid
sulfuric acid = H2SO4