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neptunium
noun
nep·tu·ni·um
nep-ˈtü-nē-əm
-ˈtyü-
: 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
These decays also contaminate the pit with helium, americium, uranium and neptunium, among other things.
—Sarah Scoles, Scientific American, 14 Nov. 2023
Other researchers have found that green rust, a highly reactive variety of rust, immobilizes radioactive neptunium.
—Patrick Morgan, Discover Magazine, 5 Apr. 2011
The technique requires bombarding uranium with a neutron to convert it to an unstable form of the element, which decays into neptunium and then fissile plutonium.
—Andrew Moseman, Discover Magazine, 25 Mar. 2010
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, 28 Apr. 2021
Sometime in 2017, the radioactive element neptunium 237 was also detected near the school.
—The Cincinnati Enquirer, Cincinnati.com, 26 July 2019
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Word History
Etymology
New Latin, from International Scientific Vocabulary Neptune
First Known Use
1941, in the meaning defined above
Dictionary Entries Near neptunium
Cite this Entry
“Neptunium.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/neptunium. Accessed 22 Dec. 2024.
Kids Definition
neptunium
noun
nep·tu·ni·um
nep-ˈt(y)ü-nē-əm
: a radioactive metallic element similar to uranium and obtained in nuclear reactors in the production of plutonium see element
Medical Definition
neptunium
noun
nep·tu·ni·um
nep-ˈt(y)ü-nē-əm
: 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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