1. CHEM 1A Review MR. BANNISTER

2. PART I: The Periodic Table

3. Atomic Number and Atomic Mass The mass number is the atomic number rounded to the closest whole number.

4. Metals vs. Nonmetals

6. Part II: Formula Writing Ionic Compounds vs. Covalent Compounds (aka. Molecular Compounds) Form between metals and nonmetals OR Form between metals and polyatomic ions Form between two or more nonmetals

7. Ionic Compounds CHARGES! Ex. Lithium nitride Ex. Magnesium oxide Ex. Potassium Sulfate Li +1 N -3 K +1 (SO 4 ) -2 Mg +2 O -2

8. Covalent Compounds (aka. Molecular Compounds) Do not worry about charges! Greek prefixes only!

9. Part III: Balancing Equations Rules for Balancing: – 1. Only change/add co- efficient; never subscripts! – 2. If a polyatomic ion appears on both sides, do not break it apart: balance it as a unit! – 3. Balance hydrogen and oxygen last!

10. Part IV: Stoichiometry Molar Mass – Take inventory of all atoms in your compounds – Look up the molar mass of each element – Multiple the number of each by the molar mass – Add em’ up!

11. Gram to Mole 1 mole of any substance = molar mass of that substance Use dimensional analysis and be sure your units cancel!