Neptunium

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Neptunium is a chemical element with the symbol Np and atomic number 93. A radioactive metallic element, neptunium is the first transuranic element and belongs to the actinide series. Its most stable isotope, 237Np, is a by-product of nuclear reactors and plutonium production and it can be used as a component in neutron detection equipment. Neptunium is also found in trace amounts in uranium ores due to transmutation reactions. Silvery in appearance, neptunium metal is fairly chemically reactive and is found in at least three allotropes: * ¿-neptunium, orthorhombic, density 20.45 g/cm³ * ß-neptunium (above 280 °C), tetragonal, density (313 °C) 19.36 g/cm³ * ¿-neptunium (above 577 °C), cubic, density (600 °C) 18 g/cm³