"Jeff" wrote in message
...
* Gordon wrote, On 6/21/2007 6:48 PM:
If you have to wear an oxygen mask at high altitudes because oxygen
(32) is heavier than other gases that make up our air (28),

And what makes you think this is true? The concentration of oxygen
remain essentially unchanged with altitude, at about 21%.

Tell that to a Mt. Everest summiteer who'd pass out without his bottled
O2..

Wilbur Hubbard