1. The Periodic Table

3. Page 120 or 450
Not reactive 1+ 1 2 3 4 5 6 2+
Periods
(rows)
Groups
(Columns)

4. Electrons Look at the outer electron shell…
A full shell = 8 electrons, closer to full = more reactive, full shell = not reactive
Reactive → how likely that atom will take part in a chemical reaction to form a compound

5. Example:

6. Example:

8. Ionic Compounds METAL ION + NON-METAL ION = IONIC COMPOUND
These compounds have the following properties:
Solids at room temperature
High melting point (needs super hot temperature to melt)
Conduct electricity when melted or dissolved in water

9. Examples of Ionic Compounds
NaCl - table salt
CaCl2 - road salt
CaO - lime (used in plaster)
MgO - laxative
CuBr2 - lasers and photo processing

10. Molecular Compounds NON-METAL +NON-METAL = MOLECULAR COMPOUND
May be solids, liquids, or gases at room temperature
Have lower melting points than ionic compounds (need less heat to melt)
Do NOT conduct electric current when melted or dissolved in water (exception → a few acids)

11. Examples of Molecular Compounds
CH4 - methane
CO - carbon monoxide
C12H22O11 - sugar
CCl4 - dry cleaning fluid
CH3OH - windshield washer fluid

12. Practice: Ionic OR Molecular
Write this down:
Are the following compounds ionic OR molecular:
MgBr2 PH3
P4O10 NaI
SiF4 Ag3P
O2F2 C8H18

13. Practice MgBr2 = ionic PH3 = molecular P4O10 = molecular NaI = ionic
Are the following compounds ionic or molecular:
MgBr2 = ionic PH3 = molecular
P4O10 = molecular NaI = ionic
SiF4 = molecular Ag3P = ionic
O2F2 = molecular C8H18 = molecular

14. Recap: METAL ION + NON-METAL ION = IONIC COMPOUND
Solids (room temp.), high melting point, conducts electricity
NON-METAL +NON-METAL = MOLECULAR COMPOUND
Any state at room temp., low melting point, does not conduct electricity (with a few exceptions)

15. Naming Ionic Compounds
Ionic compounds are named with the metal ion first, followed by the non-metal ion ending in “ide”.
Look at the periodic table → name the metal ion
Use the periodic table → name the non-metal ion
Change the ending of the NON-METAL ion to “ide”
The metal comes first, the non-metal comes second
Example: CaCl2 → calcium chloride

16. Practice:
Name the following ionic compounds:
NaBr
LiF
MgBr2
AlI3
K2S

17. Practice: NaBr → sodium bromide LiF → lithium fluoride
Name the following ionic compounds:
NaBr → sodium bromide
LiF → lithium fluoride
MgBr2 → magnesium bromide
AlI3 → aluminum iodide
K2S → potassium sulfide

18. Chemical Formula of an Ionic Compound
Look at the name of the compound and use the periodic table to find the symbols of the ions.
Write the ion charges above the symbols for the ions
Drop the + and - signs and criss-cross the ion charges to get the subscripts. If the charges are the same, they cancel - use no subscripts.
Write the chemical formula

19. Practice: cesium fluoride - strontium chloride -
Write the chemical formula for these ionic compounds:
cesium fluoride -
strontium chloride -
barium oxide (Hint: the charges are the same) -
potassium phosphide -
aluminum nitride -
* Ionic Compounds → same charges - simplify!

20. Practice: cesium fluoride → CsF strontium chloride → SrCl2
Write the chemical formula for these ionic compounds:
cesium fluoride → CsF
strontium chloride → SrCl2
barium oxide → BaO
potassium phosphide → K3P
aluminum nitride → AlN
Ionic Compounds → same charges - simplify!

21. Naming Molecular Compounds
THE RULES ARE DIFFERENT!!!!
Which non-metal comes first? → the one with the lower group number
What if they are in the same group? → the one that’s lower gets written first
Second element gets changed to end in “ide”
Remember when we counted up the atoms in a compound?
A numerical prefix is used to tell how many of each type of element are in the compound

22. Naming Molecular Compounds
Use the periodic table to name the first element.
Choose the correct prefix for the number of atoms of the element.
Use the periodic table to name the second element.
Change the ending of the second element to “ide”.
Combine the two parts of the name.

23. Mono
Only use the prefix MONO for the second element in a compound (not the first)

24. Prefixes: mono = 1 di = 2 tri = 3 tetra = 4 penta =5 hexa =6 hepta =7
octa =8
nona =9
deca =10

25. Practice:
Name the following molecular compounds:
SO2
SO3
CCl4
PCl5 CO

26. Practice: Name the following molecular compounds: SO2 → sulfur dioxide
SO3 → sulfur trioxide
CCl4 → carbon tetrachloride
PCl5 → phosphorus pentachloride
CO → carbon monoxide

27. Chemical Formula of a Molecular Compound
Look at the name of the compound. Use the periodic table to find the symbols of the elements.
Compare the prefixes in the name to determine the number of atoms of each element.
Write in the subscripts and the chemical formula.
DO NOT reduce the numbers
DO NOT cross-over!

28. Practice:
Write a chemical formula for the following molecular compounds:
sulfur dioxide →
nitrogen monoxide →
disulfur trioxide →
disulfur difluoride →
silicon tetrachloride →
diphosporus pentoxide →
carbon disulfide →

29. Practice:
Write a chemical formula for the following molecular compounds:
sulfur dioxide → SO2
nitrogen monoxide → NO
disulfur trioxide → S2O3
disulfur difluoride → S2F2
silicon tetrachloride → SiCl4
diphosphorus pentoxide → P2O5
carbon disulfide → CS2