Central concepts in naming:

1. If the compound contains a metal, it is ionic
2. Compounds have zero charge overall.
3. Know charges of ions by:
   a) "Automatics" groups IA, IIA, VIA, VIIA
   b) "Memorized" oxoanions, polyatomic ions (on naming sheet)
   c) using rule 2 when given the formula
4. To write a formula for an ionic compound, write the symbols for the cation and anion, determine their charges, then combine to achieve charge neutrality (rule 2)
5. For molecular compounds:
   a) use prefixes to tell how many atoms of an element are in the compound
   b) know the order of the elements for molecular compounds

Central concepts in assigning oxidation numbers

1. Each element in a compound has an oxidation number, which can be written above the atom's symbol.
2. The oxidation number for an atom in an element is zero.
3. The sum of the oxidation numbers for all elements (weighted by the number of atoms of that element in the compound or ion) equals the charge of the compound or ion.
4. For ionic compounds, the oxidation number of each monatomic ion equals the charge of the ion.
5. For elements in a molecular compound or ion, the oxidation number equals the charge that it would have if it is viewed as ionic.
   a) The order of the elements in the formula tells you the sign of the oxidation numbers. The element written on the left has a positive oxidation number, and the one on the right has a negative oxidation number. (Exception: H has +1 oxidation state with non-metals)
   b) Generally, use the oxidation number of a halogen (-1), oxygen (-2), or hydrogen (generally +1, but sometimes -1 in ionic compounds) with rule 3 to determine the other oxidation number.

Central concepts in predicting reactions

1. Exchange reactions:
   o C1A1 + C2A2 -> C1A2 + C2A1
   o Swap anions on each cation.
   o Check solubility of newly formed compounds. If all are soluble, write NR (no reaction).
2. Acid - Base reactions
   o HX + BOH -> H₂O + B⁺X^- (typical)
   o Identify proton donor (Acid)
   o Identify proton acceptor (Base)
   o Transfer the proton to neutralize the acid and base and form salt.
   o Check for gas formation!
3. Redox reaction
   o Look for the previous two types of reactions first -- they both shuffle cations, anions, and protons around without changing any oxidation states. Redox changes oxidation state!
   o If you suspect redox, write oxidation numbers above all elements
   o Element which increases oxidation number is oxidized
   o Element which decreases oxidation number is reduced
   o Make sure charge balances! Oxidation and reduction both must occur together!
4. All reactions conserve charge -- check!
5. All reactions conserve number of atoms of each element on each side of the arrow -- Check that the reaction is balanced.