Atomic and Molecular Masses

The journey from the microscopic world of atoms to the measurable quantities in a laboratory begins with understanding their masses. Since individual atoms are impossibly tiny, we use a relative scale, comparing their mass to a standard—the carbon-12 atom. This gives us the atomic mass of an element, which is the weighted average mass of all its naturally occurring isotopes. Similarly, the molecular mass of a compound is simply the sum of the atomic masses of all the atoms in its …