How Elements Form
Compounds
In order for atoms to
have a stable valence
shell, they will link up with
other atoms by stealing,
giving up or sharing
electrons.
This is how elements
combine to form
compounds.
There are two major types of compounds that can
form between atoms:
1. Ionic compounds: where metals (+) bonds with nonmetals (-) *stealing
2. Molecular (Covalent) compounds: where non-metals
bond with other non-metals *sharing
Ionic Compounds – made up of positive and negative ions that
results in the transfer of electrons from metal to non-metal.
Ex: Sodium + Chlorine
Here we see that Na (metal) will give it’s valence
electron to Cl (non-metal) so that they both have
stable shells!
Once this happens, the ionic charge of Na will be 1+
and the ionic charge of Cl will be 1-.
These two opposing charges will attract each other
and a chemical bond will be formed creating the ionic
compound  sodium chloride (NaCl)
Sometimes, more than one electron can be
transferred!
Ex: Calcium + oxygen
This compound’s name is
Sometimes, more than one atom of each element will
have to be involved.
Ex: calcium + chlorine
This compound’s name is
Naming Compounds
Ionic Compounds
•
•
Write the name of the first element as it
appears on the periodic table
Change the ending of the second element to “ide”
Example: NaCl
Sodium Chloride
Naming Ionic Compounds
Name the following Ionic Compounds:
LiF
Be3N2
MgCl2
CaO
AlF3
K2 S
ZnBr2
CaBr2
Naming Ionic Compounds
Name the following Ionic Compounds:
Be3N2
beryllium nitride
MgCl2 Magnesium chloride
CaO
calcium oxide
AlF3 Aluminum floride
K2 S
potassium sulfide
ZnBr2 Zinc bromide
CaBr2
calcium bromide
LiF
Lithium flouride
Naming when you have metals with more
than one Charge
• Some metals make more than one ionic charge. Most of
these are found in the transition metals on the PT
• If you use a metal that can make more than one ionic
charge, you must use a roman numeral following the
metal’s name to indicate which ion charge was used.
• The name of the non-metal still ends in “-ide”.
• NOTE: The little number in the formulas is NOT it’s charge!
It represents HOW MANY of the ions are used in the
formula.
Build the following molecules with your ion fit
kit and then give them a name in your notes.
CuBr
FeO
CuBr2
Fe2O3
NiI3
Sn3N2
NiI2
Sn3N4
Build the following molecules with your ion fit
kit and then give them a name in your notes.
CuBr
Copper (I) bromide
FeO
Iron (II) oxide
CuBr2
Copper (II) bromide
Fe2O3
Iron (III)oxide
NiI3
Nickel (III) iodide
Sn3N2
Tin (II) nitride
Nickel (II) iodide
Sn3N4
tin (IV) nitride
NiI2
What pattern appears between the
charges of the ions and how many of each
ion there are in the formula?
• The charge of the metal is how many non-metals
you need in the formaula and vice versa… most
of the time.
• This is called the criss cross method
Naming with Polyatomic Ions:
• A polyatomic ion is a group of atoms that together hold
an overall ionic charge
• If a polyatomic ion is in a formula, just state its name as
written. You do NOT change it’s ending.
Build the following molecules with your ion fit kit
and then give them a name in your notes.
Na2SO4
NH4Cl
Al(OH)3
Fe(NO3)3
Zn(BrO3)2
(NH4)3PO4
Build the following molecules with your ion fit kit
and then give them a name in your notes.
Na2SO4
Al(OH)3
Zn(BrO3)2
Sodium sulphate
Aluminum hydroxide
Zinc bromate ‘
NH4Cl
Fe(NO3)3
(NH4)3PO4
aluminum chloride
iron (III) nitrate
ammonium phosphate