Molecules can be represented by molecular, empirical, and structural formulas: the molecular formula gives the exact count of each type of atom in a molecule, the empirical formula reduces those counts to their smallest whole-number ratio (via the greatest common divisor), and the structural formula additionally shows how the atoms are bonded and arranged in space. This is a core concept in chemical nomenclature and stoichiometry, where molecular mass is computed as the sum of the atomic masses of all constituent atoms (atomic mass being the proton-plus-neutron count, averaged across an element's naturally occurring isotopes), and this mass can be partitioned to determine the percent composition by mass of each element in a compound.
Molecules can be represented by molecular, empirical, and structural formulas: the molecular formula gives the exact count of each type of atom in a molecule, the empirical formula reduces those coun…