Illustrated Glossary of Organic Chemistry

Atomic mass unit (amu; dalton): A unit of mass equal to exactly 1/12 the mass of one ¹²C atom, or 1.660538921 x 10⁻²⁷ kg. This is the approximate mass of one proton or one neutron. It is the basis of atomic weights.

Related terms: Mole, mass spectrometry, mass-to-charge ratio, m/z, isotope, ¹H, ²H, deuterium, ³H, tritium, ¹²C, carbon-12, ¹³C, carbon-13, ¹⁴C, carbon-14, nominal mass, exact mass
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