Search results
Results From The WOW.Com Content Network
Neptunium is a chemical element; it has symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. It is named after Neptune, the planet beyond Uranus in the Solar System, which uranium is named after. A neptunium atom has 93 protons and 93 electrons, of which seven are valence electrons.
One of three stable transuranic elements predicted by the new science of nucleonics in James P. Hogan's Giants series. Not naturally occurring outside of neutron stars, but trace amounts are created at the detonation of nucleonic weapons. Bureaucratium Scientific in-joke: Similar to Administratium and variation of the joke.
Francium was the last element to be discovered in nature, rather than synthesized in the lab, although four of the "synthetic" elements that were discovered later (plutonium, neptunium, astatine, and promethium) were eventually found in trace amounts in nature as well. [179]
Neptunium compounds are compounds containing the element neptunium (Np). Neptunium has five ionic oxidation states ranging from +3 to +7 when forming chemical compounds, which can be simultaneously observed in solutions. It is the heaviest actinide that can lose all its valence electrons in a stable compound.
Neptunium-235 has 142 neutrons and a half-life of 396.1 days. This isotope decays by: Alpha emission: the decay energy is 5.2 MeV and the decay product is protactinium-231. Electron capture: the decay energy is 0.125 MeV and the decay product is uranium-235; This isotope of neptunium has a weight of 235.044 063 3 u.
Trace amounts of neptunium and plutonium form in some uranium-rich rock, and small amounts are produced during atmospheric tests of nuclear weapons. These two elements are generated by neutron capture in uranium ore with subsequent beta decays (e.g. 238 U + n → 239 U → 239 Np → 239 Pu ).
Transmutation of transuranium elements (i.e. actinides minus actinium to uranium) such as the isotopes of plutonium (about 1wt% in the light water reactors' used nuclear fuel or the minor actinides (MAs, i.e. neptunium, americium, and curium), about 0.1wt% each in light water reactors' used nuclear fuel) has the potential to help solve some ...
A chemical element is a chemical substance whose atoms all have the same number of protons.The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8, meaning each oxygen atom has 8 protons in its nucleus.