Neptunium

93
Np
237.0482

Properties

Symbol Name Atomic Number Atomic Weight Group Number
Np Neptunium 93 237.0482

Description

Standard State: solid at 298 K
Color: silvery metallic

Neptunium was the first synthetic transuranium element of the actinide series discovered by McMillan and Abelson in 1940. Trace quantities of the element are actually found in nature due to transmutation reactions in uranium ores produced by the neutrons which are present. Neptunium metal has a silvery appearance and is chemically reactive.