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
The Inflation Reduction Act stipulates that small molecule drugs — composed of chemicals with a low molecular weight, encompassing most drugs on the market — are eligible for Medicare negotiation seven years after being approved by the Food and Drug Administration.
—
Nathaniel Weixel, The Hill, 1 May 2025
The trick was to pick a hydrocarbon molecule with the right molecular weight.
—IEEE Spectrum, 5 Nov. 2014
Its hyaluronic acid has a small molecular weight—all the better to penetrate the skin and deliver deep hydration—and the concealer is also infused with peptides to soften fine lines.
—Jenny Berg, Vogue, 22 Mar. 2025
In layman's terms, that means five types of HA with low, medium, and high molecular weights to address skin at different levels—not just the surface.
—Sarah Han, Allure, 22 Feb. 2025
See All Example Sentences for molecular weight
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Nathaniel Weixel, The Hill, 1 May 2025
The trick was to pick a hydrocarbon molecule with the right molecular weight.
—IEEE Spectrum, 5 Nov. 2014
Its hyaluronic acid has a small molecular weight—all the better to penetrate the skin and deliver deep hydration—and the concealer is also infused with peptides to soften fine lines.
—Jenny Berg, Vogue, 22 Mar. 2025
In layman's terms, that means five types of HA with low, medium, and high molecular weights to address skin at different levels—not just the surface.
—Sarah Han, Allure, 22 Feb. 2025
See All Example Sentences for molecular weight
Cite this Entry
“Molecular weight.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/molecular%20weight. Accessed 24 May. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share