1. How is Assembling a Skateboard Like Balancing a Chemical Equation? ? ? ?

2. Players get ready to balance!

3. Chemical Equations Formulas are used as chemical shorthand Numbers are added to balance the amount of materials. Example: your home’s gas furnace burns methane: CH 4 + 2O 2  CO 2 + 2H 2 O Methane oxygen carbon dioxide water Reactants Products of combustion yields

4. Skateboard/Chemistry Analogy You need these parts to build a skateboard + +  one deck a box of four wheels two trucks/axles Each part has its own individual property The assembled skateboard has different properties.

5. Using Symbols in Equations Here is an equation using symbols + +  DT 2 4W 2 D T W 4 The trucks have a subscript because they come in a box of 2. Like Diatomic Molecules O 2 Cl 2 Deck box of trucks/axles wheels skateboard Wheels don’t have a subscript because they are sold separately not boxed together like trucks.

7. Equations Have Several Parts This yields symbol (  ) means “makes” The symbol (+) means “combines” or “and” The “Reactants” are all of the ingredients A “Products” is what is formed or made Rule to remember: Reactants = Products, exactly  + +  Reactants DT 2 4W 2 D T W 4 Product

8. How to Increase Needed Parts 4W are used on one skateboard but These big numbers being used to increase the amount of the ingredient are called... 8W would be needed for 2 boards wheels

9. Every body needs good balance!

10. For the purpose of adjusting the Reactants so they = the Products, CH 4 + O 2  CO 2 + H 2 O For balanceing chemical equations according to the 22 4 oxygen atoms in the Reactants = EXACTLY Law of Conservation of Mass 4 oxygens in product

11. Ouch! Balancing can be tricky.

12. Just keep practicing

13. STOP HERE