1. Naming and Writing Formulas

2. Types of Compounds There are two types of compounds. Ionic: Covalent:
a metal and a nonmetal
Covalent:
contains two nonmetals

3. Ionic Compounds
Must contain a positive ion (cation) and negative ion (anion).
The cation (metal) is written first, the anion (nonmetal) is written second.

4. Naming Binary Ionic Compounds
#1 – Name the metal (written on periodic table)
#2 – Name the nonmetal, changing the ending to –ide.
Examples:
MgO
CaCl2
NaBr
Sr3P2
magnesium oxide
calcium chloride
sodium bromide
strontium phosphide

5. Writing Formulas
The subscripts tell how many of each atom you have. (The overall charge must equal zero!!)
EXAMPLE: Write the chemical formula for the compound containing Al and Br.
#1 – determine the charges
Al Br-1

6. Al+3 Br-1 AlBr3 #2 – cross the charges.
#3 – Write the formula, simplify if needed
AlBr3 1 3

7. Try this one…
Write the chemical formula for the compound containing Mg and S
#1 – determine the charges
Mg S-2

8. Mg+2 S-2 Mg2S2 MgS #2 – cross the charges.
#3 – Write the formula, simplify if needed
Mg2S2
MgS 2 2

9. Ionic Compounds with Polyatomic Ions
#1 – name the 1st part of the compound
#2 – name the 2nd part
If it is a polyatomic ion, DO NOT change the ending
If it is a nonmetal, change to –ide.
Examples:
CaCO3
Na3SO4
(NH4)2S
Calcium carbonate
Sodium sulfate
Ammonium sulfide

10. Writing Formulas: Na+1 OH-1 NaOH
Same rules apply, except if the polyatomic ion gets a subscript you MUST use parentheses around it.
Example:
Write the formula for sodium hydroxide.
Na OH-1
NaOH 1 1

11. Writing Formulas for Polyatomic Compounds
Calcium phosphate
Ca PO4-3
Ca3(PO4)2 3 2

12. Aluminum nitrite
Al NO2-1
Al(NO2)3 1 3

13. Compounds Containing Metals with Variable Charges (Transition Metals)

14. Variable Charges (Transition Metals)
The transition metals have variable charges so we have to tell what charge the ion has in our compound when we name it.
Exceptions: Zinc (+2) and Silver (+1)

15. Naming #1 – Name the metal.
#2 – Add a roman numeral telling the charge on the metal in parentheses.
I-1 II-2 III-3 IV-4 V-5 VI-6 VII-7
#3 – Name the negative ion as before.

16. Example CrO O is a -2 charge Since there are no subscripts in CrO
Cr must have a +2 charge
Chromium (II) oxide

17. FeCl3
Cl is a -1 charge
Fe must be a +3
Iron (III) chloride

18. CoCO3
Carbonate is a -2
Co is a +2
Cobalt (II) carbonate

19. Ni3(PO4)2
Phosphate = -3
Nickel (II) phosphate

20. Writing formulas:
Rules are the same as before.

21. copper (III) oxide
Cu+3 O-2
Cu2O3 2 3

22. Manganese (IV) sulfide
Mn+4 S-2
Mn2S4
MnS2 4 2

23. Iron (II) nitrate
Fe+2 NO3-1
Fe(NO3)2 1 2