Endothermic and Exothermic Reactions

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

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

reaction

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

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