Chemists, however, like to call mass "weight", e.g. "atomic weight".
I think that is a really important insight.
To restate it in more detail:
1) There is a notion of "amount of stuff" that chemists call weight, as in
atomic weight, molecular weight, et cetera. For example, if somebody asks
the formula weight of sucrose the correct answer is something like 180
grams per mole. To avoid confusion let's call this notion chem_weight.
2) The same notion exists in physics, but it is called mass. To avoid
confusion let's call this notion phys_mass.
Note that phys_mass (aka chem_weight) is independent of the choice of
reference frame.
3) Let's define the symbol g to represent the acceleration of our chosen
reference frame, relative to an instantaneously colocated freely-falling
frame (with a minus sign, so that g is a downward vector).
4) There is a notion which physicists call weight (henceforth phys_weight)
which is related to phys_mass by the formula
phys_weight = phys_mass * g
In most cases phys_weight is irrelevant to chemistry. In particular in the
spaceship reference frame, phys_weight is essentially zero, but typical
chemical processes will proceed just fine. Chem_weight (i.e. phys_mass) is
what matters to the reactions. I guess decantation and a few other
chem-lab processes would go funny in a zero-g environment, but basic
chemical reactions should be pretty much independent of g over a very wide
range.
=======================
It's amazing how two closely-allied sciences could have such wildly
divergent terminology. It's a miracle that anybody ever communicates to
anybody else.
______________________________________________________________
copyright (C) 1999 John S. Denker jsd@monmouth.com