molecular weight

noun

: 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 Its ultra-fine mist is infused with niacinamide for a shine-free finish and sodium hyaluronate—a derivative of hyaluronic acid that's smaller in molecular weight—to penetrate the surface layer of the skin for a hydrated, dewy finish. Jennifer Hussein, Allure, 3 Oct. 2024 Other larger peptides are able to repair damage at the surface of the cuticle, but a smaller molecular weight allows our peptides to penetrate all the way into the medulla, or the deepest parts of the hair’s core. Celia Shatzman, Forbes, 1 Oct. 2024 Small molecule drugs are made of chemicals that have low molecular weight, while biologic medicines are derived from living sources such as animals or humans. Annika Kim Constantino, CNBC, 15 Aug. 2024 Each has a different molecular weight, so the product can instantly revive dry, parched skin and provide additional moisture throughout the day (or night). Devon Abelman, Allure, 12 Aug. 2024 See all Example Sentences for molecular weight 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'molecular weight.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1860, in the meaning defined above

Time Traveler
The first known use of molecular weight was in 1860

Dictionary Entries Near molecular weight

Cite this Entry

“Molecular weight.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/molecular%20weight. Accessed 5 Nov. 2024.

Kids Definition

molecular weight

noun
: the weight of a molecule equal to the sum of the weights of the atoms contained in it

Medical Definition

molecular weight

noun
: 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

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