1. Naming Ionic Compounds
Science 10

2. Simple Ionic Compounds
The rules:
Name the first element
This is always the metal (cation)
The name stays as it appears on your periodic table
Name the second element
This is always the non-metal (anion)
The name will be similar to that on the periodic table with the ending –ide

3. The two element names are put together with a space in the middle
We ignore any numbers in the name – they are only there to make the charges equal

4. Ions of Non-metals Element Ion Symbol fluorine fluoride F- chlorine
chloride
Cl-
bromine
bromide
Br-
iodine
iodide I-
oxygen
oxide
O2-
sulphur
sulphide
S2-
selenium
selenide
Se2-
nitrogen
nitride
N3-
phosphorus
phosphide
P3-

5. Example KBr CaF2 First = potassium Second = bromide
Name: potassium bromide
CaF2
First = calcium
Second = fluoride
Name: calcium fluoride

6. You Try
MgCl2
CaO
Sc2O3
Na2O

7. Ionic Compound with Multivalent Elements
Some elements are able to form more than one ion – they are called multivalent
Example: Copper can be Cu+ or Cu2+ meaning it can donate 1 or 2 electrons
On your periodic table of ions, both charges will be shown

8. When compounds are made with multivalent elements, we must indicate which charge is used.
This is done by writing the roman numeral of the charge next to the name of the cation
Example: FeO
Fe2+ is required to balance with O2-
The name is: iron(II) oxide

9. You Try
MnCl2
Ni2S3
CuO
CuBr2

10. Writing a Chemical Formula
If you’re given the name, can you write the formula?
Rules:
First: find the ion for the first element
Second: find the ion for the second element
Third: use the criss-cross rule to make the formula

11. Line three = chemical formula
Three Line Method
The three line method helps us do this
Line one is the name
Line two are the ions
Line three is the chemical formula
Line one = name
Line two = ions
Line three = chemical formula

12. Example
strontium nitride
sodium oxide
strontium nitride
sodium oxide

13. Example - Answers strontium nitride sodium oxide strontium nitride
Sr N3-
Sr3N2
sodium oxide
Na+ O2-
Na2O

14. Write the formula’s for:
You Try
Write the formula’s for:
calcium oxide
potassium sulphide
zinc chloride
copper(I) phosphide

15. Naming Ionic Compounds With Polyatomic Ions

16. Polyatomic Ions
Polyatomic ions are ions that contain two or more atoms.
They have a charge which means that they will gain and lose electrons
This allows them to be part of an ionic compound
A list of polyatomic ions is found on the back of your periodic table

17. 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

18. Writing Formula’s
When there is more than one of the polyatomic ion needed you must place it in brackets
Example: lithium hydroxide
Example: calcium hydroxide

19. You Try Write the name or formula for the following: sodium hydroxide
Sr(NO2)
magnesium nitrate
NaPO4
calcium carbonate