1. Chemical Nomenclature
Ionic Compounds

2. Ionic Compounds Anion = atoms with a negative charge
Cation = atoms with a positive charge
Anions and Cations attract one another to form ionic bonds.
Very easy to predict because they always work to neutralize the charges.

3. Ionic Compounds To name an ionic compound: Cation anion –ide
Example: NaCl
Sodium Chloride

4. Magnesium fluoride Lithium bromide Cesium oxide Calcium sulfide
Practice
Name the following compounds:
MgF2
LiBr
Cs2O
CaS
Magnesium fluoride
Lithium bromide
Cesium oxide
Calcium sulfide

5. Transition Metals
Transition Metals are tricky because they can take on a variety of charges.
Ex: CuCl CuCl2

6. Transition Metals
We distinguish between the different forms of transition metals using Roman Numerals.
A Roman Numeral placed within parentheses after the name of a cation denotes the positive charge of that cation.

7. Keys to Remember Remember! Roman Numerals tell the charge of the ions
The charges of the ions determine the ratio in which they combine

8. Practice Name the following compounds: CrO Chromium (II) oxide FeF2
HgBr
SnI4
Chromium (II) oxide
Iron (II) fluoride
Mercury (I) bromide
Tin (IV) iodide

9. Practice Translate the following names into chemical formulas:
Iron (III) oxide
Beryllium chloride
Tin (II) sulfide
Potassium iodide
Fe2O3
BeCl2
SnS KI

10. Polyatomic Ions
Some ions are called ‘polyatomic ions’ because they consist of a group of atoms

11. Polyatomic Ions
When you write a chemical formula that involves polyatomic ions, you still need to balance charges to form a neutral atom.

12. Sometimes polyatomic ions occur multiple times within a compound:
Put the polyatomic ion in parentheses
add the subscript outside the parentheses
Ex: (SO4)2

13. Polyatomic Ions
Ite/ate pairs: –ate ions have one more oxygen than the -ite ion, but the same overall charge.

14. Practice Name the following compounds that contain polyatomic ions:
Mg3(PO4)2
Pb(C2H3O2)2
Cr(NO3)3
(NH4)2C2O4
Magnesium phosphate
Lead (II) acetate
Chromium (III) nitrate
Ammonium oxalate

15. Practice
Write the formula for the following compounds that contain polyatomic ions:
Potassium sulfate
Lead (II) dichromate
Ammonium chloride
Sodium hydroxide
K2SO4
PbCr2O7
NH4Cl
NaOH