Relative Atomic Mass (Ar, or Atomic Weight) is the mass of an atom of a particular chemical element that is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element, the Carbon-12 atom is the standard atom against which the masses of other atoms are compared. The Relative Atomic Mass of an element is the average mass of its atoms, compared to 1/12th the mass of a carbon-12 atom. (Refer to the Atomic Mass Unit (amu))
Related Definitions in the Project: The Property and Unit
