Question: how many atoms are in 1 mole of barium?
Answer: How many atoms of barium are present in 1.37 grams of barium? There's 6.0221415*10^23 atoms in a mole of an element, so the number of atoms in 1.37g of Barium is: (9.976188222*10^-3)*(6.0221415*10^23)=6.007801771*10^21 plus or minus a few atoms.