Atomic mass constant

Because the masses of nuclides are so small, they are normally reported as a multiple of the atomic mass constant, ma (formerly atomic mass unit, amu). The atomic mass constant is defined as exactly V12 the mass of one atom of carbon-12 ... 

The mass of an atom in terms of the atomic mass constant is numerically the same as the molar mass in grams per mole. For instance, the molar mass of carbon-12 is exactly 12 g-mol, and the mass of a carbon-12 atom is exactly 12mu. 

The quantity mle is the conventional notation for the mass-to-charge ratio of the molecular ions, with the mass a multiple of the atomic mass constant tnu and the charge a multiple of the fundamental charge e. 

By means of mass spectrometry, the mass of atoms and molecules, via mass-separated charged atomic or polyatomic ions, can be determined by measuring the mass-to-charge ratio m/z), whereby the mass of an atom or a molecule is not measured in g or kg, but in a multiple of the atomic mass constant mu (atomic mass unit). The atomic mass unit mu is defined as one-twelfth the mass of a neutral 12C atom, ma (12C), in its ground state ... 

For the calculation of the mass of an atom, molecule or ion in kg the following equation (Equation 5) for the atomic mass constant mu can be applied ... 

Note that the atomic mass constant, mu, is equal to the unified atomic mass unit, u, and is defined in terms of the mass of the carbon-12 atom mu = 1 u = ma(12C)/12. 

Arrhenius activation energy 55 astronomical unit 110 asymmetry parameter 23 atmosphere 112 atomic mass 20, 41, 94 atomic mass constant 20, 41, 89 atomic mass unit 20, 41, 75, 89, 111 atomic masses of nuclides 98-104 atomic number 20, 44 atomic orbital basis function 17, 19 atomic scattering factor 36 atomic states 28 atomic units 76, 120 atomic weight 41, 94 atomization 51, 53 attenuance 32 atto 74... 

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