We can predict which atoms will bond based
on their oxidation numbers
Ionic Bonds – Results from the complete transfer of electrons
Results in a formation of two charged atoms called ions
The atom that gains electrons becomes negatively
charged and is called an anion
The atom that loses electrons becomes positively
charged and is called a cation
The attraction of the positive and negative charges results
in a very weak bond
Covalent Bonds – Results from the sharing of electrons
The shared electrons create a very strong bond
These are the bonds that make molecules possible
We can predict which atoms will bond based
on their oxidation numbers
◦ Ex 1: Na has a +1 Oxidation Number; it wants to
lose one electron; Cl has a -1 Oxidation Number; it
wants to gain one electron
◦ Ex 2: Ca has a +2 Oxidation Number; it wants to
lose two electron; F has a -1 Oxidation Number; it
wants to gain one electron
These atoms will react quickly and violently in a 1:1
ratio to give NaCl
Ca will give one of its valence electrons to one F and
the second electron to a second F, giving CaF2
What compound is formed when Ba reacts
with Br?
The metal will take its positive oxidation
number and the non-metal will have to take
its negative oxidation number.
◦ BaBr2
◦ Only one compound can be formed
What compound is formed when Be reacts
with O?
What compound is formed when Al reacts
with I?
◦ BeO
Name of
Metal
Root of
( NonNon-metal)
-ide
◦ AlI3
1
Example 1: Sodium reacts with oxygen to
produce Na2O, what is the name of this
compound
Example 2: What is the chemical formula for
aluminum oxide
◦ First write the symbols of the elements
◦ Next write the oxidation number of each element
above that element
◦ Switch the oxidation numbers and reduce
◦ Since there is only one possible compound, we do
not have to indicate the number of elements
sodium oxide
3
-2
Al O
What is the name of Mg3N2?
◦ magnesium nitride
What is the name of Li2Se?
What is the formula for indium chloride?
What is the formula for hafnium phosphide?
The metal will take one of its positive oxidation
numbers and the non-metal will have to take
its negative oxidation number.
◦ Since the metal has more than one possible oxidation
number, multiple compounds can be formed
◦ We need a distinct name for each
◦ lithium selenide
◦ InCl3
◦ Hf3P4
Name of
Metal
Example 1: What is the name of IrBr6?
◦ First we need to determine how many electrons that
iridium needs to lose in order to satisfy 6 bromine
atoms.
Each bromine needs one electron
There is only one iridium in this compound
Therefore, the iridium atom will have to supply all six
electrons, giving it a +6 oxidation number.
iridium(VI) bromide
Oxidation State
Root of
( Metal’s
as a Roman Numeral) ( NonNon-metal)
-ide
Example 2: What is the formula for mercury(II)
nitride?
◦ First write the symbols of the elements
◦ Next write the oxidation number of each element
above that element
◦ Switch the oxidation numbers and reduce
2
-3
Hg N
2
What is the name of RuN?
◦ ruthenium(III) nitride
What is the name of MnO3
What is the formula for paladium(IV) bromide?
What is the formula for molybdenum(V)
sulfide?
◦ manganese(VI) oxide
Since nonmetals have more than one
oxidation number, there will always be more
than one compound produced
◦ Therefore we have to have a distinct name for each
compound
◦ To do this we use a prefix to indicate how many
atoms of each element are present
◦ PdBr4
◦ Mo2S5
Using prefixes
◦ The prefix mono- is only used on the second
element
Ex: PF3 is named phosphorus trifluoride
◦ If two vowels are adjacent, leave them
Ex: NI3 is named nitrogen triiodide
◦ In the case of monoxide only, drop one “o”
One – monomono-
Five – penta
penta--
Two – didi-
Six – hexahexa-
Three – tri
tri--
Seven – hepta
hepta--
Four – tetra
tetra--
Eight – octaocta-
Ex 1: What is the name of P2S3?
Ex 2: What is the name of As7I3?
Ex 3: What is the chemical formula of
dihydrogen monoxide?
Ex 4: What is the chemical formula of
dinitrogen pentaoxide?
◦ diphosphorus trisulfide
◦ heptaarsenic triiodide
◦ H 2O
◦ N2O5
Polyatomic Ions – strongly bound group of
atoms that have either lost or gained electrons
and become charged.
◦ List of common Polyatomic Ions are on the back of
your Periodic Table
◦ Polyatomic ions act as a single atom, with a single
name
◦ Subscripts within the ion cannot be changed
◦ Since there is only one oxidation number for the
metals and Polyatomic Ion, only one compound can be
produced.
Naming these compounds is just like rule 1,
except we do not add –ide to the end of the
polyatomic ion
Name of
Metal
Name of
( Polyatomic
Ion )
3
What is the name of Mg(NO3)2
What is the formula for calcium iodite?
◦ First, since the second name does not end in –ide, a
polyatomic ion is involved.
◦ Write the symbol for calcium and formula for iodite.
◦ Write the oxidation numbers above the metal and
the polyatomic ion
◦ Switch the numbers, and use parenthesis around
the polyatomic ion if necessary
◦ First, you should recognize that there are more than
two elements involved, which means that a
Polyatomic Ion is involved
◦ Next, look up the Metal in the periodic table and
confirm that it has a single oxidation number
◦ Look up the name of the Polyatomic Ion
magnesium nitrate
What is the name of KHSO4?
-1
Ca2(IO2)
◦ potassium hydrogen sulfate
◦ potassium bisulfate
What is the name of In2(C2O4)3?
◦ We must use Roman Numerals to indicate which
oxidation number the metal is using
◦ indium oxalate
What is the formula of strontium bromate?
What is the formula for germanium
phosphate?
When the metal has more than one possible
oxidation number, more than one compound
can be formed
◦ Sr(BrO3)2
Name of
Metal
Oxidation State
Name of
( Metal’s
as a Roman Numeral ) Polyatomic Ion
◦ Ge3(PO4)4
What is the name of RhMnO4?
◦ First, there are more than two elements involved
◦ Look up the oxidation and name of MnO4
It could be permanganate (-1) or manganate (-2)
◦ Finally, figure out which oxidation number the metal is
using.
If this is permanganate, rhodium would have to have a +1
oxidation number, this is not possible for rhodium.
Therefore, this must be manganate, so rhodium would
have to take its +2 oxidation number
rhodium(II) manganate
What is the formula for nickel(II)
ferrocyanide?
◦ First, since the second name does not end in ide, a polyatomic ion is involved
◦ Write the symbol for nickel and formula for
ferrocyanide
◦ Write the oxidation numbers above the metal and
the polyatomic ion
◦ Switch the numbers, and use parenthesis around
the polyatomic ion if necessary and reduce
2
-4
Ni 2(Fe(CN)6)
4
What is the name of Cr(IO)3?
◦ chromium(III) hypoiodite
◦ Strength of acid depends on how easily the
hydrogen ion is released
◦ Anytime a compound starts with H, the compound
is typically an acid
What is the name of CuMnO4?
◦ copper(II) manganate or copper(I) permanganate
What is the formula for palladium(IV)
ferricyanide?
Water (H2O) and hydrogen peroxide (H2O2) are
noteworthy exceptions
◦ Pd3(Fe(CN)6)4
Acid – any compound that is capable of giving
up a positive hydrogen ion (proton)
What is the formula for molybdenum(VI)
dichormate?
◦ Mo(Cr2O7)3
Root of
-ic acid
( NonNon-metal)
Hydro-Hydro
Ex 1: What is the name of HCl?
What is the name of HAt?
◦ Since the compound starts with H, it is probably an
acid.
◦ Use the prefix hydro-, the suffix -ic, and the word
acid
What is the name of HBr?
What is the formula for hydroiodic acid?
What is the formula for hydrofluoric acid?
hydrochloric acid
◦ hydroastatic acid
◦ hydrobromic acid
◦ HI
◦ HF
Identifying Polyatomic Acids
Naming depends on the ending of the
Polyatomic Ion
◦ Ions ending in -ate or -ide
Root of
-ic
( Polyatomic
Ion)
◦ Ions ending in -ite
Root of
Polyatomic Ion
(
acid
) -ous
Ex 1: What is the name of H3PO4?
◦ First, notice that since the compound starts with H,
we are dealing with an acid
◦ Formula will start with H
◦ Has three or more elements
Also, there are more than two elements; we should
think polyatomic ion
◦ Next, look up the name of the polyatomic ion
◦ Since phosphate ends in -ate, change the suffix to
-ic and add the word “acid.”
phosphoric acid
acid
5
Ex 2: What is the name of H3PO3?
◦ First, notice that since the compound starts with H,
we are dealing with an acid
Also, there are more than two elements; we should
think polyatomic ion
◦ Next, look up the name of the polyatomic ion
◦ Since phosphite ends in -ite, change the suffix to ous and add the word “acid.”
Ex 3: What is the formula for aluminic acid?
◦ Since there is no hydro prefix, we know that this must
be a polyatomic acid.
◦ Next, the -ic ending means that the ion must really
end in -ate
We must be looking of the aluminate ion
◦ Because this is an acid, hydrogen will be involved
◦ Write the symbols and oxidation numbers, switch the
oxidation numbers, and reduce.
phosphorous acid
1
-3
H AlO3
What is the formula for manganic acid?
What is the formula for sulfurous acid?
What is the name of HNO2?
What is the name of HNO3?
◦ H2MnO4
◦ H2SO3
◦ nitrous acid
◦ nitric acid
6