1. Chemical Reactions
Glencoe Chapter 23

2. I. Chemical reactions change substances
Substances undergo chemical changes to become new substances
A. Signs of a chemical reaction
1. Production of gas or smoke
2. Change in color (not like painting a fence)
3. Change in temperature without heating or cooling
4. Production of a solid from two liquids

3. I. Chemical reactions change substances
B. Chemical reactions rearrange atoms to form new substances
Chemical Reaction - the process in which one or more substances are changed into new substances
1. Reactants  beginning materials / substances that undergo a chemical change
2. Products  ending materials / substances that are formed as a result of a chemical change

4. II. Energy and Reactions
A. Energy added to a compound to break chemical bonds
B. Energy released from a compound to form chemical bonds
C. Exothermic reactions – reactions that release energy (usually in the form of heat and/or light)
D. Endothermic reactions – reactions that absorb energy (usually get colder during the reaction)