[nep-too-nee-uh m, -tyoo-] /nɛpˈtu ni əm, -ˈtyu-/
noun, Chemistry, Physics.
a transuranic element produced in nuclear reactors by the neutron bombardment of U-238: decays rapidly to plutonium and then to U-235. Symbol: Np; atomic number: 93.
a silvery metallic transuranic element synthesized in the production of plutonium and occurring in trace amounts in uranium ores. Symbol: Np; atomic no: 93; half-life of most stable isotope, 237Np: 2.14 × 106 years; valency: 3, 4, 5, or 6; relative density: 20.25; melting pt: 639±1°C; boiling pt: 3902°C (est)
1941, from Neptune + element ending -ium. Named for its relative position in the periodic table, next after Uranium, as the planet Neptune is one beyond Uranus. Cf. also plutonium.
neptunium nep·tu·ni·um (něp-tōō’nē-əm, -tyōō’-)
A metallic radioactive element found in trace quantities in uranium ores or synthesized; its longest-lived isotope is Np 237 with a half-life of 2.1 million years. Atomic number 93.
A silvery, radioactive metallic element of the actinide series. It occurs naturally in minute amounts in uranium ores and is produced artificially as a byproduct of plutonium production. Its longest-lived isotope is Np 237 with a half-life of 2.1 million years. Atomic number 93. See Periodic Table.
- Neptunium series
noun 1. a radioactive series that starts with plutonium-241 and ends with bismuth-209. Neptunium-237 is the longest-lived member of the series. The series does not occur in nature
light, the father of Kish (1 Chr. 8:33). 1 Sam. 14:51 should be read, “Kish, the father of Saul, and Ner, the father of Abner, were the sons of Abiel.” And hence this Kish and Ner were brothers, and Saul and Abner were first cousins (comp. 1 Chr. 9:36).
[neer-al] /ˈnɪər æl/ noun 1. citral b. See under . [si-truh l] /ˈsɪ trəl/ noun, Chemistry. 1. a pale yellow, water-insoluble, liquid aldehyde, C 10 H 16 O, having a strong lemonlike odor, consisting in natural form of two isomers (citral a or geranial and citral b or neral) usually obtained from the oils of […]
abbreviation 1. Natural Environment Research Council