1. REVIEW. Naming Ionic, Covalent and Multivalent Molecules NEW
REVIEW.... Naming Ionic, Covalent and Multivalent Molecules NEW.... Polyatomic Ions

2. Step 1: Ionic or Covalent?
Metal + Non-Metal atoms
“Give & Take” electrons
Covalent
Non-Metal atoms ONLY!
“Share” electrons
Step 1 is to Ask......
Is there a metal?
Yes = Ionic
No = Covalent

3. If it’s Ionic: (and there are only 2 elements)
Ask: Does the metal form only 1 kind of ion or more than one?
Only 1 = simple ionic naming
More than one = multivalent ionic naming

4. Simple Ionic Naming Like MgO Name the metal (the positive ion):
magnesium.
Write the root of the non-metal (the negative ion): oxygen.
Add -ide to the end of the non-metal to form:
magnesium oxide.
Name:
LiF MgI2 Fe2O3
Lithium fluoride Magnesium Iodide Iron(III)Oxide

5. Multivalent Ionic Naming
Like MnO2
Write the usual ionic name
manganese oxide
Decide which metal ion was used:
Write the ion charge of the non-metal
Count the number of each atom
Calculate the negative charge
Determine what the charge needs to
be on the metal ion to balance out the
non-metal
Add the number of the ion charge in
Roman Numerals in brackets after the metal
manganese(IV) oxide Mn
O 2-
Number of atoms 1 2
Charge
(1 Mn atom) x ( ? charge) = +4
(2 atoms) x (2- charge) =
-4 charge +4

6. Name Fe2O3 Fe O 2- Write the usual ionic name iron oxide
Decide which metal ion was used:
Write the ion charge of the non-metal
Count the number of each atom
Calculate the negative charge
Determine what the charge needs to
be on the metal ion to balance out the
non-metal
Add the number of the ion charge in
Roman Numerals in brackets after the metal
iron(III) oxide Fe
O 2-
Number of atoms 2 3
Charge
(2 atoms) x ( ? charge) =
+ 6
(3 atoms) x (2- charge) =
-6 charge

7. If it’s covalent:
1. Does it start with H or have more than 2 atoms in the molecule? Yes = Look up the name example: H2O = water No = Name the ‘binary’ covalent molecule with the prefix system N2O4 = dinitrogen tetraoxide
(made up of only 2 non-metals)

8. Naming a binary covalent molecule:
Like Si3P6
Write the most metallic atom (farthest left) first
Silicon
Add -ide to the root of the second atom’s name
phosphide
Add a prefix before each atom’s name to indicate
the number of atoms in the molecule.
(Do not add a prefix to the first atom if there is only 1)
Name:
PF5 P4O N2O
Phosphorus Tetraphosphorous Dinitrogen
pentafluoride decaoxide monoxide
Trisilicon hexaphosphide

9. What if it’s an ionic bond (metal + non-metal) but there are more than 2 elements?
These are called ‘polyatomic’ ions
many
atoms

10. Polyatomic Ions
Polyatomic ions are 2 or more atoms joined together with covalent bonds but together they act as a single ion...
Like a posse
Wherever 1 member of the posse goes... The whole group goes
Whatever mood one member of the posse is in (positive or negative) the whole group is in the same mood
The posse is always protected... The members must always stick together!

11. Polyatomic Ions Examples:
OH- : a posse... Not just O and not just H, but
always OH together!
NO2- : the negative belongs to the N and the O’s together
Are all posse’s negative?
What about the “Leadership Group” at Boucherie???
They give candy! They are a ‘positive’ posse!
NH4+: the ENTIRE group is positive
The negative mood is felt by the ENTIRE posse, not just the H or the O

12. Polyatomic Ions
See pages
Polyatomic ions are 2 or more atoms joined together with covalent bonds but together they act as a single ion...
The whole group has a + or – charge, not the individual atoms.
What is the name of the compound KClO?
K+ = potassium ClO– = hypochlorite
potassium hypochlorite

13. Polyatomic Compounds Polyatomic ions will act as a
non-metal if they are negative or
a metal if they are positive (and giving like mothers)

14. Polyatomic Compounds Examples:
Na+ and OH- = it takes the entire OH posse to get together and take the electron away from Na
NaOH = Sodium hydroxide
Mg(OH)2 = protect the posse! Put brackets around it! Mg is a bit of a tough guy (2+ ion) so it takes two OH posses to get together and steal its electrons
Ca(NO2) 2
Two polyatomic ions together: NH4OH

15. Naming Polyatomic Compounds
This is an easy one!
Write the name of the metal or the name of the positive polyatomic ion (ammonium is the only one – NH4)
Write the name of the negative polyatomic ion
MgCr2O7 = magnesium dichromate

16. Let’s make a naming poster...
Is there a metal?
Yes = Ionic
Simple Ionic Naming
Multivalent Compound Naming
Polyatomic Compound Naming
No = Covalent
Start with H or more than 2 atoms
Binary Covalent Compound Naming
Rules for Naming
Continue with the rules for naming each branch and give an example for each...
If you finish early... Work on the review assignment – Due Monday