neptunium

noun
nep·​tu·​ni·​um | \ nep-ˈtü-nē-əm How to pronounce neptunium (audio) , -ˈtyü- \

Definition of neptunium

: a radioactive metallic element that is chemically similar to uranium and is obtained in nuclear reactors especially as a by-product in the production of plutonium — see Chemical Elements Table

Examples of neptunium in a Sentence

Recent Examples on the Web The amount of neptunium found in the air monitor at the school was a thousand times below the regulatory action level, said Mr. Edwards of the DOE. Kris Maher, WSJ, "An Ohio Town Grapples With Tearing Down a Plant From the Cold War," 28 Apr. 2021 Sometime in 2017, the radioactive element neptunium 237 was also detected near the school. The Cincinnati Enquirer, Cincinnati.com, "Officials: Retest of samples shows enriched uranium in Pike County school," 26 July 2019

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

First Known Use of neptunium

1941, in the meaning defined above

History and Etymology for neptunium

New Latin, from International Scientific Vocabulary Neptune

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Time Traveler for neptunium

Time Traveler

The first known use of neptunium was in 1941

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Statistics for neptunium

Last Updated

7 May 2021

Cite this Entry

“Neptunium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/neptunium. Accessed 11 May. 2021.

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More Definitions for neptunium

neptunium

noun
nep·​tu·​ni·​um | \ nep-ˈtü-nē-əm How to pronounce neptunium (audio) , -ˈtyü- \

Kids Definition of neptunium

: a radioactive chemical element similar to uranium

neptunium

noun
nep·​tu·​ni·​um | \ nep-ˈt(y)ü-nē-əm How to pronounce neptunium (audio) \

Medical Definition of neptunium

: a radioactive metallic element that is chemically similar to uranium and is obtained in nuclear reactors as a by-product in the production of plutonium symbol Np — see Chemical Elements Table

More from Merriam-Webster on neptunium

Britannica.com: Encyclopedia article about neptunium

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