1. Writing formulas of ionic and covalent compounds

2.  The electrical charge that an element or polyatomic ion takes on in a compound  S and P blocks can be predicted by periodic table ex. Na +1  Transition Metals and Polyatomic Ions are given by table. The charge on a transition metal is given by a roman number.  Copper II means it’s a Cu +2 cation.

3.  Tell you what type of atom (element or polyatomic ion) and how many of each are combined.  Subscripts indicate the number of that element(or polyatomic ion) are present.  Superscripts used for charges only  Diatomic elements exist in pure form always bonded to another atom of itself, covalently.  H 2, O 2, Cl 2, F 2, I 2, N 2, and Br 2

4.  The more metallic and/or heavier element goes first (will be the cation). This is the element that is more to the left and down on the periodic table.  SO 2 not O 2 S  Sulfur and Phosphorous can form cations when they react with something more electronegitive (to the right of them) on the periodic table.  If using polyatomic ion, cation first, anion second.

5.  Name elements in order they appear in the formula “Carbon Oxygen”  Drop last syllable (or two) of second element and add –ide “Carbon Oxide”  Add correct prefix to show how many of each there are “Monocarbon Dioxide”  Mono is dropped if on the first name. All other prefixes stay if on the first name  “Carbon Dioxide”

6.  One= mono  Two= di  Three= tri  Four= tetra  Five= penta  Six= hexa  Seven= hepta  Eight= octo  Nine= nona  Ten= deca