atomic mass


Definition of atomic mass

: the mass of an atom usually expressed in atomic mass units also : atomic weight

Examples of atomic mass in a Sentence

Recent Examples on the Web

Not only should the chemistry of the two isotopes be the same, the slight difference in atomic mass largely washes out in the watery environment of the body. Jennifer Ouellette, Quanta Magazine, "A New Spin on the Quantum Brain," 2 Nov. 2016 Say, for example, that all of the gases and particles collected indicate the fission products are 6.2 percent atoms with an atomic mass of 137, 6.1 percent with 99, and so on. Andrew Karam, Popular Mechanics, "Nuclear Forensics: How Scientists Can Tell Whether North Korea Is Lying About Its Bomb Test," 7 Jan. 2016 Some have theorized that the soda got its name from the atomic mass of lithium, which is roughly seven. Beth Mole, Ars Technica, "7Up gets a new ingredient in Mexico—meth," 22 Sep. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'atomic mass.' 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 atomic mass

1874, in the meaning defined above

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Last Updated

29 Jun 2019

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Time Traveler for atomic mass

The first known use of atomic mass was in 1874

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More Definitions for atomic mass

atomic mass


Medical Definition of atomic mass

: the mass of an atom usually expressed in atomic mass units also : atomic weight — compare mass number

More from Merriam-Webster on atomic mass

Rhyming Dictionary: Words that rhyme with atomic mass Encyclopedia article about atomic mass

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