What is the mass of an iron atom in grams?
We must first find the molar mass of iron on the Periodic Table, which is 55.845 g/mol. Notice the molar mass is the number of grams in 1 mol. We need to find out the number of grams in one atom for which we ned to use the Avogradro's number ( 6.0221408 *10^23 atoms or molecules / mol).
55.845 g * 1mol = 9.27 x 10-23 g
1 mol 6.0221408 *10^23 atoms