1. Chapter 8 Notes
Mr Nelson 2010

2. Chemical Bonds Three basic types of bonds Ionic Covalent Metallic
Electrostatic attraction between ions
Covalent
Sharing of electrons
Metallic
Metal atoms bonded to several other atoms

3. Ionic Compounds – Review
Made up of ions
Cations (+) & Anions (-)
Metals & Nonmetals (or polyatomic ions)
Exchange of electrons
Charges Balance

4. Molecular Compounds – Intro
No ions
Charges will not balance
Composed of two nonmetals
Sharing of electrons
Covalent bonding
Naming is based on prefixes

5. Nomenclature of Binary Compounds
If both elements are nonmetals we must use prefixes.
The 1st element only gets a prefix if it is greater than 1.
2nd element always gets a prefix and change the ending to -ide

6. Nomenclature of Binary Compounds
Example of a molecular comp:
CO2 CO
CCl4

7. Practice PCl5 dihydrogen monoxide SF6 carbon trichloride
N2O disulfur hexoxide
NO2 nitrogen triiodide

8. Naming Acids An acid is any compound that starts with a hydrogen
When naming an acid:
1st locate the anion (- charge)

9. Acid Nomenclature If the anion in the acid ends in –ide (not PI)
change the ending to -ic acid and add the prefix hydro-
hydro________ic acid
HCl

10. Acid Nomenclature If the anion in the acid ends in –ate (all PI’s)
change the ending to -ic acid.
___________ic acid
HClO3

11. Acid Nomenclature If the anion in the acid ends in –ite (all PI’s)
change the ending to -ous acid.
_________ous acid
HClO2

12. Acids – Finishing Up If you have the name and need to find the formula
Example: Acetic Acid
Cross off the –ic and add at –ate
Acetate! = C2H3O2-
Finish by adding the correct # of H’s (1 for every negative)
HC2H3O2 is acetic acid 

13. Warm Up HBr Chlorous Acid FeS Copper(I) fluoride
PBr5 dinitrogen dioxide
K2SO4 nitrogen monoxide
CCl4 hydroiodic acid
HNO3 potassium nitrate
LiCl phosphoric acid

14. Covalent Bonding Covalent bond – atoms share electrons.
There are several electrostatic interactions in these bonds:
Attractions between electrons and nuclei
Repulsions between electrons
Repulsions between nuclei

15. Lewis Dot Structures ONLY Valence (outer) electrons are involved.
Lewis dot structures can be drawn for:
atoms
molecules
Lewis dot structures show structure of a molecule, and help predict shape.

16. Steps to Writing Lewis Structures
Find the sum of valence electrons of all atoms in the polyatomic ion or molecule.
PCl3
(7) = 26

17. Writing Lewis Structures
Arrange element symbols to show how atoms are connected – show electrons as dots.
Draw in the valence electrons of each of the atoms
Keep track of the electrons:

18. Writing Lewis Structures
Connect the lines to form single bonds.
1 line = 2 electrons
Keep track of the electrons:

19. Writing Lewis Structures
Finish by checking for octets.
Hydrogen only needs 2 electrons to be happy
Keep track of the electrons:

20. Writing Lewis Structures
If the central atom does not have an octet…
…form multiple bonds until it does. Example: HCN

21. Exceptions!
Boron and Aluminum are okay with only 6 e- around them
BF3

22. Exceptions If the Lewis Dot Structure you are drawing is an ion:
Use [] and specify the charge
Add or subtract electrons
Positive charges take away electrons
Negative charges add electrons
Example: Br-