Chemical Nomenclature
How to write and say chemical
formulas
General Chemistry 10-11
Elements

Elements are said with
just their name




Mg = magnesium
Ca = calcium
Some elements never
exist by themselves
These are called diatomic
molecules

There are seven of them
and they make a seven on
the periodic table
The Diatomic Molecules








These would still be said
by their elemental name
but would be written with
a subscript of 2
N2
O2
F2
Cl2
Br2
I2
H2
Compounds
Most elements are not found separately
but combined in a compound with
something else
 The reason for this is the octet rule

We want 8…eight is great!
Octet Rule


Noble gases are what
all elements aspire to
be like electronically
These elements have
8 electrons in highest
energy level
Ionic Bond

Atoms will either give up or take electrons
to get to have eight in their highest energy
level
Hey, can you
help me out
and gimme an
electron?
Why certainly, I
have one I don’t
want anyway.
Give up/take away electrons
Charges
Sodium now has a +1 charge since it has
lost an electron
 Chlorine a minus charge since it gained an
electron

Ionic Bond

Opposites attract, so a bond is formed
between the two of them.
(or until
water
breaks
us apart)
Ionic Compound
The combination of Na+ and Cl- form the
compound NaCl
 An ionic compound will always consist of:

A metal ion (also called a cation, the + one)
 A non-metal ion (also called an anion, the - one)


CATION ALWAYS COMES BEFORE THE
ANION; both in the name and the formula
Naming Ionic Compounds




When naming ionic
compounds
Just say the name of
the metal
For the non-metal,
drop the ending and
add -ide to it.
NaCl = sodium
chloride
Practice Problem #1

Name the following
ionic compounds
1.
2.
3.
4.
5.
ZnO
LiBr
Mg3N2
BaS
K3P
Zinc oxide
Lithium bromide
Magnesium nitride
Barium sulfide
Potassium phosphide
Determining metal and non-metal
charge

Where are the metals on the periodic
table?


Metals always have what charge?
Where are the nonmetals?

Nonmetals always have what charge?
We’ll see the charges of
the different families on
the following slide.
Using the periodic Table to find an
ion’s charge
+1
-3
+2
-4
We’re going to
forget all about
the middle of
the table for
now.
-1
-2
Combining metals and nonmetals

When combining a metal and a non-metal, the
overall charge of the compound must be zero.
You must balance
out the overall
charge!
Combining metals and nonmetals
Take for instance calcium nitride.
 What is the charge of the calcium ion?
 What is the charge of the nitride ion?

Combining metals and nonmetals
Ca+2 means each calcium ion has 2 more
electrons than it wants
 N-3 means each nitride ion needs 3 more
electrons.

Hey buddy, can
you spare 3
electrons?
Sorry, I only have
two.
Maybe I can
help!
HEY, What
about me?
YEAH!
Hang loose, man.
I’ll get one of my
buddies.
YO, YO, YO.
Your hero has
arrived.
YEAH!
I still need
two more.
I need to
get rid of
two more.
The ions found they were still attracted to one
another due to their opposing charges. And they all
lived happily ever after.
Practice Problem #2

Give the formulas for the following
compounds
1.
2.
3.
4.
Beryllium iodide
Potassium sulfide
Magnesium oxide
Strontium fluoride
BeI2
K2S
MgO
SrF2
Now is the time to learn
“SWITCHY SWITCHY”
and reduce!
Transition Metals



The middle block of
elements
All cations
Most can take on
multiple charges

Some Exceptions
 Zn
= +2
 Ag = +1
Transition metal compounds

In order to tell what charge a transition
metal has, put its charge in parenthesis

For instance Copper (II) Oxide means…


the copper ion here has a +2 charge
For instance Copper (I) Oxide means…

the copper ion here has a +1 charge
What are the formulas of
these two ionic compounds?
Practice Problem #3

Give the formula of the following
compounds:
1.
Tungsten (IV) Chloride
WCl4
2.
Gold (III) phosphide
AuP
3.
Tin (II) fluoride
SnF2
4.
Zinc sulfide
ZnS
Polyatomic Ions




Sometimes, atoms get together but
can’t quite get to an overall zero
charge.
With
polyatomic ions
This is where they become a
we don’t have to
polyatomic ion
change the
They’re still a charged particle
ending
(mostly anions) so they can combine
with an opposing charged ion to
produce a compound
Naming is easy, we just say the
name of the polyatomic ion
Ionic Compounds involving a
polyatomic ion
Ionic Compounds involving a
polyatomic ion
Ionic Compounds involving a
polyatomic ion
Practice Problem #4

Name the following compounds
1.
2.
3.
4.
5.
(NH4)2S
CaSO4
Ba(NO3)2
K2CO3
Mg3(PO4)2
Ammonium sulfide
Calcium sulfate
Barium nitrate
Potassium carbonate
Magnesium phosphate
Practice Problem #5

Write formulas for the following
compounds
Aluminum nitrate
 Beryllium sulfate
 Calcium phosphite
 Ammonium sulfite
 Strontium nitrite

Al(NO3)3
BeSO4
Ca3(PO3)2
(NH4)2SO3
Sr(NO2)2
Covalent Bonds
Compounds formed by two non-metals
 More of a sharing of electrons rather than
a give-take relationship

Can you
spare an
electron?
JINX!
Why don’t you share an
electron? You know
sharing is caring!
Co=together
Valent=valence electrons…
therefore, covalent is
sharing electrons!
Naming Covalent Bonds
Prefixes on back of periodic table
 If there is only one of the first element, no
prefix. Otherwise attach prefix
 Second always gets prefix and -ide ending
(just like ionic anion)
 Name these

ICl5
 N2O

Practice Problem #7

Name the following covalent compounds
1.
2.
3.
4.
CO2
PCl5
CO
P3F6
Carbon dioxide
Phosphorous pentachloride
Carbon monoxide
Triphosphorous hexaflouride
Practice Problem #8

Give the formula for the following
compounds





Sodium acetate
Nickel (II) chloride
Carbon dioxide
Sulfur trioxide
Triphosphorous tetrachloride
NaC2H3O2
NiCl2
CO2
SO3
P3Cl4
One more thing…



If the ionic compound begins with a hydrogen
ion, it’s an acid
We name binary acids by adding hydro as a
prefix to the root of the anion and add ic, then
add the word acid
Name these:




HCl
HI
HF
HBr
Acids involving polyatomic anions
These are even easier,
 They’ll always involve oxygen
 If an -ate ion, use root of
polyatomic and add -ic
 If an -ite ion, use root of
polyatomic and add -ous
 Then just add the word acid

If I ATE it I
would
say IC!
Practice Problem #6

Write the formulas for these acids
1.
2.
3.
4.
5.
6.
7.
Sulfuric acid
Sulfurous acid
Carbonic acid
Nitric acid
Nitrous acid
Phosphoric acid
Phosphorous acid
H2SO4
H2SO3
H2CO3
HNO3
HNO2
H3PO4
H3PO3