molecular weight


Definition of molecular weight

: the average mass of a molecule of a compound compared to ¹/₁₂ the mass of carbon 12 and calculated as the sum of the atomic weights of the constituent atoms

Examples of molecular weight in a Sentence

Recent Examples on the Web Honorable mention in the senior division was won by John Bernardin of Fallbrook Union High School for a colorimetric chemical analysis exhibit, and Lulu Capra of Fallbrook for a display showing how to measure molecular weight. Merrie Monteagudo, San Diego Union-Tribune, 16 Apr. 2021 The team could measure this aboard the aircraft with a device called a mass spectrometer, which calculates molecular weight. Matt Simon, Wired, 3 Nov. 2020 But Fuster said low molecular weight heparin and apixaban both showed positive effects. Maggie Fox, CNN, 26 Aug. 2020 While low- and medium-molecular-weight HAs do the classic hyaluronic acid job of attracting and binding water, higher molecular weight HA tends to have a more occlusive effect, sealing in that hydration. Sarah Jacoby, SELF, 3 Oct. 2019 In practice, though, Dr. Newsom says that molecular weight isn’t really something to spend your time worrying about. Sarah Jacoby, SELF, 3 Oct. 2019 The new armor technology takes ultrahigh molecular weight polyethylene, or UHMWPE, and adds silica nanoparticles for strength. Kyle Mizokami, Popular Mechanics, 24 Sep. 2019 In addition to the molecular shrinkage that happens during the freeze-drying process, each tablet is formulated with hyaluronic acid of the lowest molecular weight to begin with. Rebecca Dancer, Allure, 18 Apr. 2019 Their results showed that the brown algae extract, which had the lowest molecular weight, did the best. Sarah Jacoby, SELF, 13 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'molecular weight.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of molecular weight

1860, in the meaning defined above

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Time Traveler for molecular weight

Time Traveler

The first known use of molecular weight was in 1860

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Statistics for molecular weight

Last Updated

20 Apr 2021

Cite this Entry

“Molecular weight.” Dictionary, Merriam-Webster, Accessed 13 Jun. 2021.

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More Definitions for molecular weight

molecular weight


Medical Definition of molecular weight

: the mass of a molecule that may be calculated as the sum of the atomic weights of its constituent atoms

More from Merriam-Webster on molecular weight Encyclopedia article about molecular weight


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