Quote Originally Posted by VeeDubb65 View Post
I'll the him answer on his own, but my $0.02 in case he doesn't come back around for a while.

You're looking at this the wrong way..

You are correct that a single molecule of Cr2O3 will not change it's size, weight, etc, etc.
about it is structure weight etc check this link right side table
Chromium(III) oxide - Wikipedia, the free encyclopedia