Mass not density
Wiki link http://en.wikipedia.org/wiki/Mole_%28unit%29
"By this definition, a mole of any pure substance has a mass in grams
exactly equal to that substance's
molecular<http://en.wikipedia.org/wiki/Molecular_mass>or atomic
mass <http://en.wikipedia.org/wiki/Atomic_mass>; e.g., 1mol of
calcium<http://en.wikipedia.org/wiki/Calcium>-40
has an approximative mass of 40g, because the Ca-40 isotope has a mass of
39.9625906 amu <http://en.wikipedia.org/wiki/Atomic_mass_unit> on the C-12
scale. In other words, the numerical value of a substance's molecular or
atomic mass in atomic mass
units<http://en.wikipedia.org/wiki/Atomic_mass_units>is the same as
that of its molar
mass <http://en.wikipedia.org/wiki/Molar_mass>the mass of one mole of that
substancein grams <http://en.wikipedia.org/wiki/Grams>."
He said lighter, that refers to mass, not density.
So by weight He is about 4X as heavy as H, not 50X
I stand by my statement.
On Mon, Mar 21, 2011 at 6:55 PM, <pennell at cox.net> wrote:
> Neither of yoiu are correct. Hydrogen is roughly 2 times lighter than
> helium. Comparisons of atomic masses to determine density does not hold
> water. Also I fail to see why any comparison to helium is even being made.
>
> Keith
>
> ---- Richard Ewald <richard.ewald at gmail.com> wrote:
> > Also BTW Hydrogen is not 50 times lighter than Helium. Hydrogen has an
> > atomic weight of 1.0079. Helium has an atomic weight of 4.0026. If you
> > want something that is 50 times heavier than Hydrogen it would be
> Vanadium a
> > metal with an atomic weight of 50.942.
> > Rick
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