1. Endothermic and Exothermic Reactions

2. Chemical Reactions Indicators of Chemical Reactions 5 Different Signs Color Change Odor Change Change in State (liquid to solid, etc) Gives off a precipitate Temperature Change

3. Temperature Changes 2 Different Types Endothermic Endo = In Therm = Temp Heat taken In; Temperature Drops Exothermic Exo = Out / Exit Therm = Temp Heat released; Temperature Rises reaction

4. Endothermic A reaction that absorbs or takes in heat More energy is supplied than released Temperature lowers Occurs when the bonds between atoms break (energy is absorbed) Examples: Photosynthesis Melting Ice Cubes Evaporation of water Baking Bread Cooking an Egg

5. Exothermic A reaction that releases heat More energy is released than supplied Temperature Rises Occurs when atoms bond together (energy is released) Example: Burning fossil fuels A candle flame Iron Rusting