Photo by Ra’ike
Remember…
Rules for Naming Ions
Examples of naming ions:
sulfide
nitride
potassium
oxide
lithium
bromide
chloride
hydrogen (+), hydride (-)
It is also important that you can
identify the names of
. Polyatomic ions are
elements that
have a
!
sulfate
carbonate
permanganate
sulfite
hydroxide
nitrate
CaBr2
calcium bromide
Step 1: Write the name of the metal ion.
Step 2: Write the name of the nonmetal ion.
1.
NaF
sodium fluoride
3.
SrCl2
strontium chloride
5.
CaO
calcium oxide
2.
MgO
magnesium oxide
4.
Li2S
lithium sulfide
6.
KI
potassium iodide
When polyatomic ions are used, simply use
the name of the polyatomic ion in the
compound.
1.
NH4F
ammonium fluoride
3.
Mg(NO3)2
magnesium nitrate
2.
CaSO4
calcium sulfate
4.
NaOH
sodium hydroxide
You can also determine the formula of an ionic
compound from its name. To do this, you will need to
use what you already know about the Periodic Table.
magnesium iodide
+2
Mg
I
MgI2
-
Step 1: Write the symbol and charge of the metal ion
using the Periodic Table.
Step 2: Write the symbol and charge of the nonmetal
ion using the Periodic Table.
Step 3: Determine the formula from the ions.
This is just as easy to do with polyatomic ions. You just
need to use the table of polyatomic ions found on the
naming compounds reference sheet.
strontium nitrate
+2
NO3
Sr
Sr(NO3)2
Step 1: Write the symbol and charge of the metal ion.
Step 2: Write the formula and charge of the
polyatomic ion using your STAAR Reference Sheet.
Step 4: Determine the formula from the ions.
Be very careful that you do not mix up the names
of ions. This is very common for beginners to
naming.
Helpful Hint:
If the ion ends in –ide, it is probably from the
periodic table. If the ion ends in –ate or –ite,
it is a polyatomic ion. If you’re not sure, just
check the list to see if it is there!
Remember that the names of transition
metals includes their charge because their
charges are less predictable.
What are the charges of the transition
metals below:
We know they are positive because
metals are always positive.
The charges of the transition metals are important when
you are determining the formula of an ionic compound.
iron (III) oxide
+3
Fe
O
Fe2O3
-2
Step 1: Write the symbol and charge of the metal ion
using the ROMAN NUMERAL given.
Step 2: Write the symbol and charge of the anion.
Step 4: Determine the formula from the ions.
KI
SnCl4
BaSO4
NaCl
SrS
CuCO3
AlBr3
Li3N
So why do atoms share electrons?
Atoms share electrons so that they can both
be in the most stable configuration!
So when are atoms the most stable?
Atoms are the most stable when they have 8
valence electrons in their outer energy level.
(Hydrogen and Helium only need 2 valence electrons.)
Nonmetals
Chemical reactions occur when atoms gain,
lose, or share electrons.
Sharing electrons creates a covalent bond
Nonmetals can _______
share electrons to
form a covalent bond.
molecule
This creates a ___________.
There are 7 elements that exist in nature
as diatomic molecules.
What elements exist as diatomic molecules?
H2, N2, O2, F2, Cl2, Br2, I2
There are millions of covalent compounds. These
can be classified into many different types of
compounds. Each type of compound has a different
set of rules for naming. You will be learning about
the easiest type of covalent compound to name:
Nonmetals can share electrons in many different
ways. This means that two nonmetals can create
multiple compounds together.
Each of these contains a different ratio of elements.
Because of this, we have to make sure that the name
of the compound explains the correct ratio.
To show the
correct ratio of
elements, we
use prefixes.
Steps for Naming
Binary Covalent Compounds
N2O4
dinitrogen
nitrogen
tetroxide
oxide
Step 1: Write the name of the first nonmetal.
Step 2: Write the name of the second
nonmetal changing its ending to -ide.
Step 3: Add prefixes to specify how many of
each element are present.
Rules for Using Prefixes
Rule 1: Prefixes are only for COVALENT compounds.
Rule 2: The prefix mono- is never used on the first
element of a binary covalent compound. Without a
prefix it is assumed that there is only 1.
Example: CO2 is carbon dioxide, not
monocarbon dioxide.
Rule 3: Remove the -o or -a from a prefix before
adding it to oxide.
Example: CO is carbon monoxide,
and not carbon monooxide.
How would you write each of
the prefixes in front of oxide?
Remember: Remove the -o or -a from a prefix
before adding it to oxide. Leave -i alone.
mono- ____________
monoxide
trioxide
tri- ____________
pentoxide
penta- ____________
hepta- ____________
heptoxide
nona- ____________
nonoxide
di- ____________
dioxide
tetroxide
tetra- ____________
hexa- ____________
hexoxide
octoxide
octa- ____________
deca- ____________
decoxide
Name the binary covalent compounds
that are found on your notes.
carbon dioxide
carbon disulfide
phosphorous tribromide
phosphorous pentabromide
diphosphorous pentasulfide
dinitrogen monosulfide
silicon disulfide
nitrogen tribromide
dinitrogen tetrachloride
Because of the prefixes, it is very
easy to go from the name of a binary
covalent compound to its formula.
dinitrogen tetrafluoride
N2 F4
Step 1: Write the symbol of the first nonmetal and
the subscript that matches the prefix.
Step 2: Write the symbol of the second nonmetal
and the subscript that matches the prefix.
Write the formulas of the binary
covalent compounds in your notes.
CCl4
PCl5
N2O
CS
BH3
S2Br6
SiS2
P I3
NCl3
IF 7
N2O4
PCl3
CO
ICl
S4N4
H2O
ClF5
NO2