Neptunium lies in Row 7 of the periodic table. The periodic table is a chart that shows how chemical elements are related to one another. Neptunium is the first transuranium element. The term transuranium means "beyond uranium." Any element with an atomic number greater than 92 (uranium's atomic number) is called a transuranium element. Elements in Row 7 are also called actinide elements. This name comes from the first element in Row 7, actinium. Scientists have now found about 18 isotopes of neptunium. They are all radioactive. Neptunium was once a very rare element, but it can now be somewhat easily produced in a nuclear reactor. A nuclear reactor is a device in which nuclear fission reactions occur. Neptunium is used commercially only in specialized detection devices. Continue reading from Chemistry Explained
According to John Emsley in his book, Nature’s Building Blocks: An A-Z Guide to the Elements (Oxford University Press, 1999), Italian scientist Enrico Fermi was the first to claim he discovered element 93, in 1934. He hypothesized that elements heavier than uranium (element 92) could be created by bombarding uranium with neutrons. Theoretically, this would add one neutral mass unit to the uranium atoms, which would then undergo beta decay, or loss of a negative charge that turns a neutron into a proton, resulting in an element with 93 total protons. Continue reading from Life Sciences
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. 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. Continue reading from Chemicool
PubChem Neptunium (National Library of Medicine)
Neptunium (Chemistry Learner)
Its Elemental: Neptunium (JLab Education)
Neptunium (Royal Society of Chemistry)
