: a radioactive metallic element that is chemically similar to uranium and is obtained in nuclear reactors as a by-product in the production of plutonium—symbol Np; see element table
Biographical Note for NEPTUNIUM
Nep·tune,\ˈnep-ˌt(y)ün\ Roman mythological character. Neptune was originally the god of fresh water. Later he became identified with the Greek god Poseidon, a deity of the sea. In art Neptune is usually represented as a bearded man holding a trident and sometimes a fish. The planet Neptune was named after him and the element neptunium was named after the planet.