from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The sum of the atomic weights of all the atoms in a molecule. Also called formula weight.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. the sum of the atomic weights of every atom in a molecule
from the GNU version of the Collaborative International Dictionary of English
- adj. the weight of a molecule of any gas or vapor as compared with the hydrogen atom having weight of 1 as a standard; the sum of the atomic weights of the constituents of a molecule. For more precise measurements, the weight of the carbon isotope carbon-12 is used as the standard, that isotope having the value of 12.000. In this systen, now used almost universally, the hydrogen atom has a weight of 1.0079.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. (chemistry) the sum of the relative atomic masses of the constituent atoms of a molecule
Sorry, no etymologies found.