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mass number

noun
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Definition of mass number

: an integer that approximates the mass of an isotope and designates the number of nucleons in the nucleus

Examples of mass number in a Sentence

Recent Examples on the Web Madhavan added that in rural areas, young girls might drop out of school in mass numbers. — Jessie Yeung, CNN, "India has just five years to solve its water crisis, experts fear. Otherwise hundreds of millions of lives will be in danger," 3 July 2019 Madhavan added that in rural areas, young girls might drop out of school in mass numbers. — Jessie Yeung, CNN, "India has just five years to solve its water crisis, experts fear. Otherwise hundreds of millions of lives will be in danger," 3 July 2019 Madhavan added that in rural areas, young girls might drop out of school in mass numbers. — Jessie Yeung, CNN, "India has just five years to solve its water crisis, experts fear. Otherwise hundreds of millions of lives will be in danger," 3 July 2019 That means that the agricultural industry, when using these antibiotics as bulking agents, is allowing mass numbers of drug-resistant bacteria to become part of our food chain. — K.n.c., The Economist, "How what’s in our heads changes what’s in the world," 15 Nov. 2019 The pilot whale is notorious for stranding in mass numbers, for reasons that are not entirely understood. — Washington Post, "Pilot whales strand on Iceland beach in group of 50 or more," 20 July 2019 Madhavan added that in rural areas, young girls might drop out of school in mass numbers. — Jessie Yeung, CNN, "India has just five years to solve its water crisis, experts fear. Otherwise hundreds of millions of lives will be in danger," 28 June 2019 An initial look at comments supporting the blackout repeal didn’t indicate similar issues with fake names or mass numbers of identical letters. — Paul Overberg, WSJ, "The NFL’s Other Problem: Fake Fans Lobbying for the Blackout," 7 Sep. 2018

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

1923, in the meaning defined above

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Time Traveler for mass number

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The first known use of mass number was in 1923

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Statistics for mass number

Last Updated

11 Jan 2020

Cite this Entry

“Mass number.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/mass%20number. Accessed 22 January 2020.

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More Definitions for mass number

mass number

noun

Medical Definition of mass number

: an integer that approximates the mass of an isotope and that designates the number of nucleons in the nucleus the symbol for carbon of mass number 14 is 14C or C14 — compare atomic mass

More from Merriam-Webster on mass number

Britannica.com: Encyclopedia article about mass number

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