Unified atomic mass unit
From Mass Spec Terms
Orange Book Entry
This unit (u) is based on the standard that the mass of 12C is exactly 12 u. The older symbol, amu, using the standard based on the mass of 16O is no longer recommended. In biochemistry the term dalton, symbol Da, is sometimes used but is not here recommended.
Gold Book Entry
unified atomic mass unit
Non-SI unit of mass (equal to the atomic mass constant), defined as one twelfth of the mass of a carbon-12 atom in its ground state and used to express masses of atomic particles, u = 1.660 5402(10) x 10??????????????????????????27 kg.
Proposed New Entry
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