Appearance and Characteristics
Harmful effects:
Neptunium is harmful due to its radioactivity.
Characteristics:
Neptunium is a silvery radioactive synthetic metal. (Miniscule quantities of neptunium-237 and neptunium-239 are found in nature as a result of beta decay of uranium.) Neptunium exists in three allotropes: it has an orthorhombic structure at normal temperatures, a tetragonal structure above 280oC and a cubic structure above 577oC. (2)
Uses of Neptunium
Neptunium is used mainly for research purposes.
When bombarded with neutrons neptunium-237 is used to produce plutonium-238 which is used for spacecraft generators and terrestrial navigation beacons.
Neptunium is also used in neutron detection equipment.