Question: 

Atoms are very, very small pieces of matter. This fact should go without saying, but it behooves us to be reminded of just how small atoms are. Chemists and physicists use a unit of measurement to represent quantities of different materials based on how many atoms (or molecules) there are in a particular sample. This unit of measurement is called the mole.

1 mole of pure iron metal weighs about 56 grams. Based on the definition of a mole, how many atoms of iron are in this 56 gram sample?