See Also: neptunium(medicine)
neptunium(dictionary)

neptunium (iou)



neptunium noun. L19.
[from NEPTUNE + -IUM, after uranium.]
A supposed chemical element similar to tantalum found in a sample of tantalite. Only in L19.
A radioactive metallic chemical element of the lanthanide series, atomic no. 93, which is produced artificially. (Symbol Np.) M20.