
#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: 10,766

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



Register to reply 
Related Discussions  
Exponential Growth and Logarithmic Growth  Calculus  2  
Crystal Growth  Czochralski technique, finding concen. of dopant after growth  Introductory Physics Homework  1  
Elemental composition of the body  Chemistry  5  
uniqeness of elemental particles  Quantum Physics  15 