atomic mass unit

noun

Definition of atomic mass unit 

: a unit of mass for expressing masses of atoms, molecules, or nuclear particles equal to ¹/₁₂ the mass of a single atom of the most abundant carbon isotope 12C

called also dalton

Examples of atomic mass unit in a Sentence

Recent Examples on the Web

What’s more, the large compounds are likely fragments of even larger parent molecules that could weigh thousands of atomic mass units, Postberg says. National Geographic, "Right Stuff for Life Found on Small Saturn Moon," 27 June 2018 Previously, Cassini detected lighter, gassy molecules such as methane and ethane, which contain one or two carbon atoms and a smattering of hydrogens; these molecules weigh in at around 15 atomic mass units. National Geographic, "Right Stuff for Life Found on Small Saturn Moon," 27 June 2018

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

First Known Use of atomic mass unit

circa 1942, in the meaning defined above

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22 Sep 2018

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The first known use of atomic mass unit was circa 1942

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More Definitions for atomic mass unit

atomic mass unit

noun

Medical Definition of atomic mass unit 

: a unit of mass for expressing masses of atoms, molecules, or nuclear particles equal to ¹/₁₂ the mass of a single atom of the most abundant carbon isotope 12C

called also dalton

More from Merriam-Webster on atomic mass unit

Nglish: Translation of atomic mass unit for Spanish Speakers

Britannica.com: Encyclopedia article about atomic mass unit

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