1. Plutonium and neptunium exist in the Earth crust, in uranium ores as a result of transmutation reactions of uranium, in extremely low concentrations.
2. An explanation for these extremely low concentrations: is the fact that Pu and Np also decay to other radioactive isotopes (the half lives not so great of Pu and Np isotopes don't permit the accumulation on earth), the transmutation reactions are very rare (the number of neutrons from the spontaneous fission of uranium is low, the neutron capture cross section is not great, etc.).
All transuranic elements are artificial chemical elements, impossible to found in the nature (excepting of course a possible contamination); plutonium is found naturally in ultratraces in some uranium ores (Oklo mine, Africa) as a result of some nuclear reactions - neutrons capture and beta decays. 23892U + 10n ----→ 23992U --- β- -→ 23993Np --- β- -→ 23994Pu
Neptunium is also present in nature, accompanying uranium ores, but only in ultra traces concentrations.
Ex.: neptunium, deuterium (isotope of H)
The element with chemical symbol Np is Neptunium. Neptunium is a radioactive Lanthanide and is part of the unofficial Promethium family. It has 93 electrons in 7 shells and is next to Uranium and Plutonium.
Uranium plutonium and hydrogen
Uranium because uranium has the highest atomic number, 92, of the natural, actinide elements. Elements higher than 92 are man-made elements. Check the periodic tables to see for yourself!~
Neptunium, with the chemical symbol Np, is the chemical element with the atomic number 93.
No element name Venus exists. Elements' name derived from planets are Mercury, Uranium, Neptunium, and Plutonium
Ex.: neptunium, deuterium (isotope of H)
Neptunium is a member of the actinides group.
The element with chemical symbol Np is Neptunium. Neptunium is a radioactive Lanthanide and is part of the unofficial Promethium family. It has 93 electrons in 7 shells and is next to Uranium and Plutonium.
Uranium plutonium and hydrogen
The transuranic elements are those with an atomic number greater than 92, the atomic number of uranium. Only neptunium (Atomic number 93) occurs naturally on earth, the rest plutonium americium etc are made artificially. See the wikipedia article http://en.wikipedia.org/wiki/Transuranic_elements
Uranium because uranium has the highest atomic number, 92, of the natural, actinide elements. Elements higher than 92 are man-made elements. Check the periodic tables to see for yourself!~
Plutonium is a not stable, radioactive element. The IUPAC table Atomic weights of the elements, 2009 don't mention an officially atomic weight for plutonium. But you can find tables with atomic masses of the all 20 known plutonium isotopes (Audi, Wapstra, Thibault, 2003).The atomic mass of the most important isotope (239Pu) is 239,052156.
Plutonium 239
These elements (neptunium and heavier) are called transuranic elements or trans-uranium elements. They could also properly be called artificial and radioactive.*Both plutonium and neptunium, first known through synthesis, have been found to occur naturally in trace amounts, along with americium, curium, berkelium and californium. These occur through a natural version of the synthesis process, within quantities of uranium ore.
#93 Neptunium See also the periodic table at the link below.
There are many different elements involved in the construction of an atomic bomb, but the elements that actually cause an atomic explosion are either uranium (specifically the U235 isotope) or plutonium.