名詞 neptunium:

1. a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium
   同義詞：Np, atomic number 93

nep.tu.ni.um

n.Symbol Np （名詞）符號 Np
A silvery, metallic, naturally radioactive element, atomic number 93, the first of the transuranium elements. Its longest-lived isotope is Np-237 with a half-life of 2. million years. Found in trace quantities in uranium ores, it is produced synthetically by nuclear reactions.See table at element
镎：一種銀白色的、金屬性天然放射性元素，原子序數(shù)為93，第一個超鈾元素。其周期最長的同位素為Np-237，半衰期為20萬年。見于鈾礦的示蹤量中，由核反應(yīng)合成生產(chǎn)出來參見 element

來源：
After the planet Neptune [from the fact that it follows uranium in the periodic table]
源自 Neptune [來自于在周期表里，從它位于鈾元素之后的事實]