What is a 
          Chemical 
         Reaction?
     A Chemical reaction occurs when ever a 
     chemical bond is formed, broken or 
     rearranged.
     A chemical reaction will always create a 
     new substance.
        Energy and 
          Chemical 
         Reactions
     When a reaction occurs it’s either going 
     to give off energy or take in energy.
     Exergonic reactions – release energy  
     (usually breaking bonds)
     Endergonic reactions – take in energy 
     (usually making bonds)
          Chemical 
          Equations
     A chemical equation contains the 
     following:
       Reactants: The starting chemicals
       Products: The ending (resulting) 
       chemicals
       Yield sign: The arrow that shows the 
       change.
       Coefficients: Numbers in front of the 
       molecule.
       Subscript: Number behind and at the 
       bottom of the atom or molecule.
         Balancing
     Chemical Equations should balance.
     The number of atoms in the reactants 
     should match the number of atoms in 
     the product.
     You can not create or destroy energy or 
     matter.
        Is this equation balanced?
            Moles
     When trying to count very small particles 
     like atoms a counting unit was created 
     called the mole.
     1 mole = 6.022 x 1023  particles
     It is the number of particles in exactly 12 
     grams of carbon.
     Amedeo Avegadro was the Italian scientist 
     who came up with this unit, so it is also 
     called Avegadro’s Number.