
#1
Dec2012, 05:22 AM

P: 22

I am studying for my undergraduate Astrophysics module and the lectures notes say that that all abundances are measured relative, in terms of H = 12.00 by mass or number of atoms. Is this correct? I thought it was all based off of Carbon = 12. Am I missing something?




#2
Dec2012, 08:23 AM

Mentor
P: 10,864

The definition of amu (used for isotope masses) depends on carbon12, maybe you mixed those two definitions?



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