atomic mass

noun

: 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 How changes in atomic mass leave clues to our climatological past. Dan Zak, Washington Post, 15 July 2019 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, 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, 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, 22 Sep. 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'atomic mass.' 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

1874, in the meaning defined above

Time Traveler
The first known use of atomic mass was in 1874

Dictionary Entries Near atomic mass

Cite this Entry

“Atomic mass.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/atomic%20mass. Accessed 4 Mar. 2024.

Kids Definition

atomic mass

noun
: the mass of any kind of atom usually expressed in atomic mass units

Medical Definition

atomic mass

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

More from Merriam-Webster on atomic mass

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