I guess what you're asking about is whether there are spaces between
the water molecules. The molecules don't have sharp boundaries, since
their electron clouds gradually tail off. That makes it a little
arbitrary to say where the molecule stops, and whether any of the space
is 'empty'. So it might be best to just use the words in the standard
way, and say that a glass full of water is full of water.
Mike W.
(published on 10/22/2007)
