1. Ion Humour

2. Simple Ionic Compounds

3. What are ions?
Atoms that lose an electron or gain an electron are called ions.
Fluorine is a negative ion because it will gain an electron (-).
All non-metallic ions gain electrons.
Lithium is a positive ion because it will lose an electron
All metallic ions lose electrons.

4. Oh…to be Noble... Valence electron = 1 Valence electron = 7
Fluorine
Lithium
Valence electron = 1
*To become stable lithium will lose one electron.
Valence electron = 7
*To become stable fluorine will gain one electron.

5. + Cations and Anions Positive ions are called cations.
Negative ions are called anions.
When cations and anions combine, they form an ionic compound... +

6. Energy in Bonding
Ionic bonding results in a chemical change through the process of a reaction between two elements or substances.
The mass, number and types of elements, and the energy involved must all remain constant in this process.
WHAT GOES IN MUST COME OUT!
Energy can be absorbed and/or released in several forms - heat, light, sound...

7. K+ + Cl- = KCl Formula Writing
In order to have a stable compound, the number of electrons lost by one ion must equal the number of electrons gained by the other ion.
K Cl- = KCl

8. Formula Writing Continued….
In many cases, the number of electrons lost by one ion does not initially balance the number of electrons wanted by the other ion…or vice versa.
Na O2- = Na2O

9. Formula Writing Hints
The “Criss-Cross” method is a fast shortcut to balancing.
Take the charge of each ion and drop it over to the other symbol
Reduce if necessary (lowest common denominator)
Ca N3- = Ca3N2
The Table of Ions has all of the charges for ions…
Always write the charges as the number, then the charge,
ie. O 2-, not O -2
Remember that only metals with nonmetals will have charges to balance – do not do this with molecular compounds!

10. Naming Ionic Compounds
1. The cation (+ ion, metal) is first and keeps its regular metallic name.
2. The anion (- ion, non metal) is second. The anion name is the root; simple ions have the suffix (-ide).
eg. Ca3N2 = calcium nitride
Common anion names:
sulfur = sulfide bromine = bromide
nitrogen = nitride chlorine = chloride
phosphorous = phosphide fluorine = fluoride

11. 2. Mg + N = Mg2+ + N3- =
Mg3N2

12. 3. H + O = H+ + O2- =
H2O

13. 4. K + Cl = K+ + Cl- =
KCl

14. 5. K + O = K+ + O2- =
K2O

15. 6. Ca + O = Ca2+ + O2- =
CaO