1. Naming Ionic Compounds
Science 10

2. Simple Ionic Compounds
Let’s look at this example: KBr
Name the metal (cation) first
Potassium
Name the non-metal (anion) next, end it with –ide
Bromine becomes bromide
Put together: Potassium bromide

3. Practice Na2O Sodium Oxide Name the metal: Name the non-metal:
Put them together to get: Sodium Oxide
Note: It takes two Na+ to combine with one O2- to make a neutral compound!

4. If you’re given the name, can you write the formula?
Writing Formulae
If you’re given the name, can you write the formula?
Strontium nitride
Strontium is Sr2+
Nitride is N3-
We must combine them to be equal to zero
Need 3 Sr2+ to combine with 2 N3-
Answer is Sr3N2

5. Multivalent Ionic bonding
Some elements are capable of forming more than one ion
Example: Copper can be Cu+ or Cu2+ meaning it can donate 1 or 2 electrons
We show this on the periodic table by a split cell showing both charges

6. There is an option of Fe2+ and Fe3+
When compounds are made with multivalent elements, we must choose or indicate which charge we are referring to in the chemical equation.
Look at Iron
There is an option of Fe2+ and Fe3+
FeO would be called Iron (II) oxide
It takes Fe2+ to balance out charges with O2-
We indicate the optional charge with roman numerals; 2= II, 3=III, 4=IV and so on
The roman numeral is put after the cation

7. Practice Naming
FeCl2
MnO
Fe2O3
TiO2

8. Practice & Homework
1. Practice writing ionic formulae with Investigation 2
2. Practice naming ionic compounds with Investigation 3

9. Naming With Polyatomic Ions

10. Polyatomic Ions
Polyatomic ions are ions that contain two or more atoms.
They are electrically charged, which means that they are always looking at gaining or losing one or more electrons.
So, polyatomic ions basically look like molecules (only contain non-metals), but with a charge.

11. Most polyatomic ions are anions, meaning they have more electrons than the neutral atoms that are in the ion.
Hydroxide (OH-) has one extra electron beyond what the neutral oxygen and hydrogen atoms would have
Although most are anions, there are some, which are cations. The most common is NH4+ (ammonium).

12. Naming with Polyatomic Ions
It is the same for naming ionic compounds but you must use the names of the polyatomic ions.
The endings will not change to –ide
Examples:
LiOH
NH4Cl
BaSO3

13. Writing Formula’s
When there is more than one of the polyatomic ion needed you must place it in brackets
Ex. Lithium hydroxide LiOH
No brackets because Li+ and OH- balance in a 1:1 ratio
Ex. Calcium hydroxide Ca(OH)2
Use brackets because Ca2+ needs 2 OH- in order to balance

14. Try Some Write the name or formula for the following: NaOH HCN
Magnesium nitrate
CaCO3

15. Practice & Homework
Complete Investigation 4