1. THE LAW OF CONSERVATION OF MASS

2. MASS cannot be CREATED OR DESTROYED during the course of a CHEMICAL REACTION. Reactants -------> Products Mass of Reactants = Mass of Products

4. Iron + Oxygen -----> Rust Fe (100 g) + O (?g) ------> 143g mass reactants = mass products 100g + ? = 143g WHAT IS THE MASS OF OXYGEN??? mass oxygen = 43 g C OF M with HARRY POTTER

5. BALANCING CHEMICAL EQUATIONS WATCH AND LEARN ….. AND THEN GIVE IT A TRY!

6. 2 HCl + Zn ZnCl 2 + H 2 COEFFICIENT- (used in balancing equations) A number placed in front of a chemical formula which indicates how many MOLECULES of a compound is needed for a reaction to take place –MULTIPLIES THE NUMBER OF ATOMS OF EACH ELEMENT IN THE FORMULA

7. RULES TO FOLLOW DO NOT CHANGE THE CHEMICAL FORMULA BY ADDING SUBSCRIPTS DO NOT CHANGE THE CHEMICAL FORMULA BY CHANGING SUBSCRIPT NUMBERS THE ONLY WAY TO CHANGE THE AMOUNT OF ATOMS IN A CHEMICAL FORMULA OR ELEMENT IS TO PLACE A COEFFICIENT IN FRONT OF THE FORMULA OR ELEMENT.

8. 1.Na + MgF 2 NaF + Mg 2.SnO 2 + H 2 Sn + H 2 O