Re: [amsat-bb] Whats in Helium?

["Bill Jones" <wejones@xxxxxxxxxxxx>]

> >Doesn't it have to do with the fact that Rubber balloons are porous and you
> >not only let some of the helium out, but you also converted some to another
> >gas.  Osmosis at it's best.
> 
> Helium is a noble gas. It's inert. You can't convert it to another
> gas, at least not without a fusion reactor.
> 
> It leaks out of rubber balloons because helium is a) monatomic (i.e.,
> it exists as individual He atoms, not as diatomic pairs like H2, O2,
> N2, Cl2, etc) and b) it is a very small atom to begin with. So it can
> go right through the pores in the rubber.
 
Relative to Bob's original question about whether his helium contains air, 
I'd guess that it didn't.  I've seen exactly the same symptoms with helium 
that was better than 99.999% pure.  My GUESS is that as others have said, the 
helium gets out by permeation through the rubber, but in addition, some air 
goes through the rubber, since the air concentration is greater outside the  
balloon than inside.  It won't permeate as fast as the helium, but it doesn't 
take as much to destroy the lift either.  Just my guess.


**************************************
*Bill Jones  N3JLQ  Sweden Maine     *
* wejones@megalink.net               *
* http://www.megalink.net/~wejones   *
**************************************
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org