molecular weight
Save This Word!
noun Chemistry.
the average weight of a molecule of an element or compound measured in units once based on the weight of one hydrogen atom taken as the standard or on 1/16 (0.0625) the weight of an oxygen atom, but after 1961 based on 1/12 (0.083) the weight of the carbon-12 atom; the sum of the atomic weights of all the atoms in a molecule. Abbreviation: mol. wt.
QUIZZES
QUIZ YOURSELF ON “ITS” VS. “IT’S”!
Apostrophes can be tricky; prove you know the difference between it’s and its in this crafty quiz!
Question 1 of 12
On the farm, the feed for chicks is significantly different from the roosters’; ______ not even comparable.
Also called formula weight.
Origin of molecular weight
First recorded in 1875–80
Words nearby molecular weight
molecular rotation, molecular sieve, molecular spectrum, molecular surgery, molecular volume, molecular weight, molecule, mole drain, mole fraction, molehill, mole mapping
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
Example sentences from the Web for molecular weight
British Dictionary definitions for molecular weight
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Medical definitions for molecular weight
molecular weight
n.
The sum of the atomic weights of all the atoms in a molecule.formula weight
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Scientific definitions for molecular weight
molecular weight
The sum of the atomic weights of the atoms contained in a molecule. Also called relative molecular mass
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for molecular weight
The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.