Neptunium
[nep'tjuːnɪəm] or [nɛp'tjunɪəm]
解释:
(noun.) a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium.
录入:罗宾逊--From WordNet
解释:
(n.) A new metallic element, of doubtful genuineness and uncertain indentification, said to exist in certain minerals, as columbite.
校对:蒂米