Atomic Mass Unit (amu) is a physical constant equal to 1/12 of the mass of an unbound atom of carbon-12. The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus. In the modern usage 1 amu (Atomic Mass Unit) = 1 u (unified atomic mass unit) = 1 Da (Dalton) = 1 g/mol, Symbol: m or ma). (Refer to the Atomic Mass)
Reference Definition by Wikipedia: Atomic Mass Unit (amu) is the unified atomic mass unit or Dalton (symbol: u, or Da) is a standard unit of mass that quantifies mass on an atomic or molecular scale (atomic mass). One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol. It is defined as one twelfth of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest, and has a value of 1.660539040(20)×10^-27 kg, or approximately 1.66 yoctograms.
Related Definitions in the Project: The Property and Unit
