Chemical Reactions and Stoichiometry Chapter 8 Balancing Chemical Reactions (Wednesday 1/5/11 P1,3,5 & Thursday 1/6/11 P2,4,6)? Indicators of a Chemical Reaction ? evidence of a chemical reaction Evolution of heat and light (simultaneously) Production of a gas (bubbles, odor change) Formation of a precipitate (solid, cloudy) Color change (not introduced by an outside source such as dye or ink) Characteristics of a Chemical Reaction ? the atoms in one or more reactant rearrange when bonds are broken and/or created to produce one or more new products with different properties than the reactants had before the reaction. Reactants - on the left? react to one another and/or their environment. Products ? on the right of the reaction ? produced/created from reactants.