n. 镎

[化] 镎Np

[医] 镎(93号元素)

[ noun ]
a radioactive transuranic metallic element; found in trace amounts in uranium ores; a by-product of the production of plutonium
<noun.substance>

Neptunium \Nep*tu"ni*um\, n. [NL.]
A radioactive metallic element of atomic number 93, produced
in nuclear reactors from Plutonium or Uranium. Symbol Np; The
atomic weight of the most stable isotope is 237.0482.
[PJC]