1. Exothermic and Endothermic Reactions It’s a give and take relationship!!!!

2. Every Reaction Involves Energy 1.D uring a reaction…bonds absorb energy and break 2. N ew bonds form…energy released

3. Symbols In Chemical Reactions

4. Heat is given off Light Energy Electrical Energy Thermal Energy

5. What Is A Chemical Reaction? Chemical Reaction: the process by which one or more substances undergo change to produce one or more different substancesChemical Reaction: the process by which one or more substances undergo change to produce one or more different substances How To Identify A Chemical Reaction Has Occurred Or Is Happening 1. Gas Formation 3. Color Change 4. Energy Change 2. Solid Formation

6. Parts To A Chemical Reaction C O2O2O2O2 CO 2 1.Reactants: starting materials of a chemical reaction 2.Products: substances formed

7. Chemical Reaction 2 2Na Cl 2 2NaCl What Do You Notice About All The Atoms?

8. Chemical Reactions Must Be Balanced!!!! It’s a Law!!!!!!!!!!! The Law Of Conservation Of Mass **Mass is neither created nor destroyed in ordinary chemical reactions

9. Exothermic Reactions Chemical Reaction in which energy is released or removedChemical Reaction in which energy is released or removed 2 Na + Cl 2  2 NaCl + Energy Energy is in the products in an Exothermic Reaction

10. Endothermic Reactions Chemical reaction in which energy is absorbed 6 CO 2 + 6 H 2 O + Energy  C 6 H 12 O 6 + 6 0 2 Energy is in the reactants in an Endothermic Reaction