1. Ions and Ionic Compounds

2. Valence Electrons and Ions
All atoms want to have a full outer orbital to be stable.
This means that most atoms will need to have 8 (or 2) electrons in their outermost shell. We call this a stable octet
An atom can lose or gain electrons to obtain a stable octet.
Atoms that have gained or lost electrons are called ions.

3. Ions
Atoms that lose electrons have a positive charge and are called cations.
Atoms that gain electrons have a negative charge and are called anions
The noble gases have full outer orbits and therefore do not gain/lose electrons.

4. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 2 3 5 6 7 8

5. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 1 
Lose 1  +1 2 3 5 6 7 8

6. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 1 
Lose 1  +1 2 2 
Lose 2 +2 3 5 6 7 8

7. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 1 
Lose 1  +1 2 2 
Lose 2 +2 3  3
Lose 3 +3 5 6 7 8

8. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 1 
Lose 1  +1 2 2 
Lose 2 +2 3  3
Lose 3 +3 5  5
Gain 3 -3 6 7 8

9. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 1 
Lose 1  +1 2 2 
Lose 2 +2 3  3
Lose 3 +3 5  5
Gain 3 -3 6 6 
Gain 2 -2 7 8

10. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 1 
Lose 1  +1 2 2 
Lose 2 +2 3  3
Lose 3 +3 5  5
Gain 3 -3 6 6 
Gain 2 -2 7  7
Gain 1 -1 8

11. # electrons in valence shell Gain/Loss of Electrons
Group
# electrons in valence shell
Gain/Loss of Electrons
Charge 1 1 
Lose 1  +1 2 2 
Lose 2 +2 3
Lose 3 +3 5
Gain 3 -3 6 6 
Gain 2 -2 7
Gain 1 -1 8
None!

12. The Formation of Ions The Formation of Ions
A Bohr-Rutherford diagram for a Sodium Atom
Atoms are neutral because they contain the same number of positive and negative charges.
A Bohr Ruther ford Diagram of a sodium ion
Na1+ (sodium atom with one lost electron)

13. Ionic Compound METAL + CATION (positive ion) Loses an electron(s)
Ex. Li → Li1+
 NON-METAL
ANION (positive ion)
Gains an electron(s)
Ex. F → F1-

14. Ionic Compounds
Transfer of Electrons to become STABLE and give a STABLE OCTET (full outer shell)
The transfer of electrons results in a POSTIVE atom and NEGATIVE atom and these oppposite charges ATTRACT
The forces that keep the IONS together are called an IONIC BOND

15. Examples Try these Lithium Fluoride Beryllium Oxide Magnesium Fluoride
Aluminum Chloride

16. Molecular Compounds NON-METAL + METAL NO ions
Valence electrons (outer shell) are SHARED
The attraction between atoms in a molecular compound are called COVALENT BONDS

17. Oxygen Gas Double Bond

18. Fluorine Gas Single Bond

19. Examples
Try the following: H2 O2
H2O
CO2
CH4
C6H12O6