>PS. Just out of curiosity, are you asking out of personal interest or are you trying to apply this to some practical application (ie. answer the ATPL MET questions)
Palgia :
Just personal interest. Hopefully I haven't given the authorities any ideas for an even dumber test question than usual. (Even though I'm in Canada, it seems like all aviation tests around the world are designed in the same obscure way
)
V1 - thx, I think I'll just accept the fact that molecules (usually) don't change size. Getting into the details tends to be incomprehensible anyway
BW: Thx for the info
Mike