Atomic and Molecular Mass
How the mass of atoms and molecules is measured and compared.
Atomic Mass
Atomic mass is expressed in atomic mass units (amu), defined relative to one-twelfth the mass of a carbon-12 atom.
Molecular Mass and Formula Mass
Molecular mass is the sum of the atomic masses of all atoms in a molecule. For ionic compounds, we use the term formula mass instead, since they do not exist as discrete molecules.
Lesson 2 of 26