What happened to heat energy in the reaction? ( thermic-of or pertaining to heat) Endothermic Endo -from the Greek meaning inner Energy is absorbed and held in during this type of reaction. Chemistry in a bag experiments Exothermic Exo -from the Greek meaning outer Energy is released and given off during this type of reaction. Chemistry in a bag experiments

Types of chemical reactions 4 types

Chemical equation a short easy way to show a chemical reaction, using symbols instead of words 2Cu + O  2CuO REACTANTSPRODUCTS 2H  2H 2 O + O 2 REACTANTSPRODUCTS

4 types of chemical reactions 1) Synthesis reaction- 2 or more simpler substances combining to produce a more complex substance

2) Decomposition Reaction 2H  2H 2 O + O 2 REACTANTPRODUCTS

3) Replacement Reaction When on element replaces another in a compound OR when 2 elements in different compounds trade places Metals lab ( a single replacement experiment) Mg + HCl  Mg Cl + H 2 The Mg replaced the Hydrogen and formed a new chemical bond with Chlorine. Hydrogen went back to being a gas. We proved it was H gas by using the wood splint test.

4. Double Replacement