1. THE “MOLE”
A Mole (mol)  is a unit of measurement used for counting very small things (atoms, molecules, etc.)
A mole of something is similar to a dozen of something
1 dozen elephants = 12 elephants
1 dozen pencils = 12 pencils
1 dozen chemistry students = 12 chemistry students
How are 1 dozen elephants similar to 1 dozen pencils?
1 Mole  = 6.02 x 1023 of anything   
Or 602,000,000,000,000,000,000,000
Also known as Avogadro’s Number
1 mole of elephants = 6.02 x 1023 elephants
1 mole of pencils = 6.02 x 1023 pencils
1 mole of chem students = 6.02 x 1023 chem students
Or,
1 mole of copper atoms =  6.02 x 1023 copper atoms
1 mole of oxygen atoms = 6.02 x 1023     oxygen atoms
How is 1 mole of copper similar to 1 mole of oxygen ?
How are they different?

2. Moles and Mass: Atomic and Formula Mass
If 1 mole of an element = (6.02 x 1023 of that element)
What would 1 mole of an element weigh?
Look on the Periodic Table!
The atomic mass given on the periodic table is = grams per mol ( 𝒈 𝟏 𝒎𝒐𝒍 ) or grams in 1 mole!
For example:  
    A) Elements and the Mole (Atomic mass):
    1 mole of H atoms weigh = grams
    2 moles of H atoms weigh = (2 x ) = grams
    1 mole of  O atoms weigh  = grams
    B) Formulas and the Mole (Formula Mass) :
    1 mole of water (H2O) would weigh?
            H = (2 x ) = grams
           +     1 O =  grams
                              grams

3. 2 moles of H2 + 1 mole of O2 → 2 moles of H2O
C) Chemical Equations and the Mole:
2 H2  +  1O2  →  2 H2O
The coefficients = quantity of each reactant and product in MOLES!
    So the above equation really says…….
   
    2 moles of H2  +   1 mole of O2 →  2 moles of H2O
So, how much would 2 moles of water weigh?
1 mole of water (H2O) weighs =   grams
            2 H = (2 x ) = grams
           +     1 O = _             grams
                            grams