 Reactants: On the left side of the arrow. They form products

 Products What the reaction produces On the right side of the arrow

 Coefficient Always precedes a formula How many units of what it precedes. For example, 3 hydrogen molecules, 1 nitrogen molecule, 2 ammonia molecules. No coefficient means 1 This is the number you change when balancing

 Subscript Part of the formula NEVER change it

 Arrow Yields Produces NEVER means equals

 Phase indicators (aq): aqueous: dissolved in water (g): gas: if this is on the product side and (aq) or (l) is on the reactant side, you will see bubbles (l): liquid: note this is different from (aq) (s): solid: if this is on the product side, you will produce a precipitate.

 NaCl (aq): means sodium chloride dissolved in water  NaCl (l): means molten sodium chloride