[Mesa-users] Question about mass fraction

[Francis Timmes]

since a mass fraction is a mass divided by a mass,
a mass fraction is dimensionless (no units, a pure number).

fxt





> On May 17, 2019, at 4:45 AM, d10631026陳瑜安 <d10631026 at gapps.fg.tp.edu.tw> wrote:
> 
> How can I mark the unit of mass fraction?
> 
> d10631026陳瑜安 <d10631026 at gapps.fg.tp.edu.tw> 於 2019年5月17日 週五 下午3:08寫道：
> Thanks!
> 
> On Fri, May 17, 2019, 11:57 Francis Timmes <fxt44 at mac.com wrote:
> in simple terms, the mass fraction of a substance within a mixture is 
> the ratio of the mass of that substance to the total mass of the mixture
> 
> X_i = mass_i / mass_tot
> 
> since the individual masses sum to the total mass, the mass fractions sum to unity
> 
> sum X_i = mass_tot / mass_tot = 1
> 
> your picture seems ok.
> 
> fxt
> 
> 
> 
> 
> > On May 15, 2019, at 7:32 PM, d10631026陳瑜安 <d10631026 at gapps.fg.tp.edu.tw> wrote:
> > 
> > Dear MESA Users,
> > 
> > I'm not sure whether the meaning of mass fraction is like what I draw in the picture.
> > I would like to ask about the meaning of mass fraction.
> > 
> > Thank you,
> > Ann
> > <QUESTION.png>_______________________________________________
> > mesa-users at lists.mesastar.org
> > https://lists.mesastar.org/mailman/listinfo/mesa-users
> > 
>