1. 3-6 Covalent Bonding (12.1)
And you

2. “Co” = sharing and “valent” refers to valence electrons: covalent = sharing of one or more valence electrons between atoms. In the examples below, dots again represent valence electrons and a line represents 2 shared dots (single bond).

3. Examples H2 each H atom has 1 valence e- = 2e- s H. + H. = H:H
CH4 each H has 1 e-, C has 4 = 8 e- s
H. + H. + H. + H C = H
H C H

4. H2O
Each hydrogen has one e-, O has 6 e- = 8 e- H. + H. + O = H O H

5. 3-7 Naming Covalent Compounds ~ Type/Class 3 Rules (Section 5.3)
Class 3 rules involve covalent bonding, the sharing of valence electrons between 2 nonmetals.
Since there are no charges for covalent bonding, prefixes are used to indicate the number of atoms.
See location on periodic table please.

6. # Prefix 1 mono 2 di 3 tri 4 tetra 5 penta 6 hexa 7 hepta 8 octa
nona
deca

7. Names
First element ~ use a prefix ONLY if the # of atoms is 2 or greater.
Second element ~ ALWAYS needs a prefix and then “ide”.

8. Examples CO2 = Carbon dioxide CO =
Carbon monoxide (note not mono oxide)
N2O4 =
Di nitrogen tetroxide (note not tetra oxide)
BF3 =
Boron tri fluoride

9. P4O6 =
Tetra phosphorus hex oxide
H2O =
Di hydrogen mon oxide
*** normally the prefix goes together with the atom i.e. monoxide. They are separate here to emphasize the process.

10. Formulas from names Look at the prefix for the number of atoms
Sulfur dioxide =
SO2
Sulfur trioxide =
SO3
Sulfite (careful) =
SO (this is a polyatomic ion)

11. Xenon tetrafluoride =
XeF4
Tetraphosphorus decoxide =
P4O10
Dioxygen difluoride =
O2F2

12. Practice naming all types/classes
Start by looking at where the first element is located on the periodic table.
Keep in mind if it is in column 1a, 2a, or the 3 step region – use type 1 naming rules
If it starts in the transition metal area, use type II naming rules (cation charge!)
If it starts above the staircase, then type III rules (mono, di, tri...)

13. Fe(OH)3
Fe is in the transition metal area so type II
Iron (III) hydroxide
Al2S3
Al is in the 3 step region so type I
Aluminum sulfide
N2Cl4
Nitrogen is above the staircase so type III
Dinitrogen tetrachloride

14. Sr(NO3)2
Sr is in group 2a so type 1 naming rules
Strontium nitrate
Ammonium carbonate
Ammonium is a polyatomic ion with a +1 chg.
NH4+ + CO3-2 = (NH4)2 CO3
Iron(II) phosphate
Fe+2 + PO4-3 = Fe3(PO4)2
Silicon tetrabromide
SiBr4

15. Lithium sulfate
Li SO = Li2SO4
Lithium sulfite
Li SO = Li2SO3
Lithium sulfide
Li S = Li2S