Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Neptunium reactions

T. W. Newton, The Kinetics of the Oxidation Reduction Reactions of Uranium, Neptunium, Plutonium, andMmericium inMqueous Solution, TlD-26506, U.S. Energy, Research, and Development Administration (ERDA) Technical Information Center, Washington, D.C., 1975. [Pg.206]

Mixed second-order kinetics. Consider an electron transfer reaction between the triva-lent ions of neptunium and iron in aqueous solution 23... [Pg.41]

The chemical similarity between lanthanide and actinide metals suggests that C2H I2 might also react with actinide metals. Preliminary experiments found no reaction between thorium or uranium metals and a THF solution of Plutonium and neptunium... [Pg.46]

Reduction Reactions of Uranium, Neptunium, Plutonium and Americium in Aqueous Solutions" National Technical Information Service, U. S. Department of Commerce Springfield, Virginia, 1975. (b) Buxton, G. V. and... [Pg.250]

Elements 43 (technetium), 61 (promethium), 85 (astatine), and all elements with Z > 92 do not exist naturally on the Earth, because no isotopes of these elements are stable. After the discovery of nuclear reactions early in the twentieth century, scientists set out to make these missing elements. Between 1937 and 1945, the gaps were filled and three actinides, neptunium (Z = 93), plutonium (Z = 94), and americium (Z = 95) also were made. [Pg.1576]

Burkhart and Newton [J. Phys. Chem., 73 (1741), 1969] have studied the kinetics of the reaction between vanadium (II) and neptunium (IV) in aqueous perchlorate solutions... [Pg.74]

Neptunium is similar to uranium in that the potentials of the four oxidation states are widely separated. There have been only a few studies on the hydrolytic reactions of neptunium. Np02 unlike U02 is comparatively stable and represents a transition... [Pg.49]

It should be noted that the ytterbium listed above was a mixture discovered in the mineral erbia by de Marignac in 1878 and not the neoytterbium/aldebaranium element renamed ytterbium that was foimd in the mineral ytterbia. The columbium was a mixture found in the mineral samarskite and was not the present day columbium/niobium. The ionium listed above was a mixture of terbium and gadolinium that was found in the mineral yttria and does not refer to °Th. Finally, the neptunium refers to material fovmd in niobium/tantalum minerals and does not refer to the 1940 discovery of the trans-uranium element produced via a neutron capture reaction on a uranium sample. [Pg.3]

Neptunium - the atomic niunber is 93 and the chemical symbol is Np. The name derives from the planet Neptune (the Roman god of the sea), since it is the next outer-most planet beyond the planet uranus in the solar system and this element is the next one beyond uranium in the periodic table.lt was first synthesized by Edwin M. McMillan and Philip H. Abelson in 1940 via the nuclear reaction n, y) U P = p. The longest half-life associated with this mistable... [Pg.14]

Plutonium - the atomic number is. 94 and the chemical symbol is Pu. The name derives from the planet Pluto, (the Roman god of the underworld). Pluto was selected because it is the next planet in the solar system beyond the planet Neptime and the element plutonium is the next element in the period table beyond neptunium. Plutonium was first synthesized in 1940 by American chemists Glenn T. Seaborg, Edwin M. McMillan, Joseph W. Kennedy and Arthur C. Wahl in the nuclear reaction U( H, 2n) Np = P => Pu. The longest half-life associated with this unstable element is 80 million year Pu. [Pg.16]

This article presents a general discussion of actinide metallurgy, including advanced methods such as levitation melting and chemical vapor-phase reactions. A section on purification of actinide metals by a variety of techniques is included. Finally, an element-by-element discussion is given of the most satisfactory metallurgical preparation for each individual element actinium (included for completeness even though not an actinide element), thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium. [Pg.4]

Heavier isotopes Es-253, Es-254 and Es-255 can be produced in a nuclear reactor by multiple neutron capture reactions that may occur when uranium, neptunium and plutonium isotopes are irradiated under intense neutron flux. These and other isotopes also are produced during thermonuclear explosions. [Pg.292]

Neptunium, the first transuranium element, was discovered hy E. M. McMdlan and P. H. Ahelson in 1940 in Berkeley, California. It was produced in the cyclotron in a nuclear reaction by bombarding uranium-238 with neutrons. An isotope of mass 239 and atomic number 93 and ti/2 of 2.4 days was produced in this reaction. Neptunium-237, the longest-lived alpha-emitter with half-life 2.14x10 years, was discovered two years later in 1942 by Wahl and Seaborg. The new element was named after the planet Neptune, the planet next to Uranus in the solar system. [Pg.604]


See other pages where Neptunium reactions is mentioned: [Pg.249]    [Pg.249]    [Pg.203]    [Pg.206]    [Pg.212]    [Pg.515]    [Pg.415]    [Pg.83]    [Pg.86]    [Pg.357]    [Pg.133]    [Pg.135]    [Pg.152]    [Pg.152]    [Pg.166]    [Pg.57]    [Pg.19]    [Pg.443]    [Pg.20]    [Pg.307]    [Pg.317]    [Pg.320]    [Pg.177]    [Pg.89]    [Pg.64]    [Pg.64]    [Pg.363]    [Pg.421]    [Pg.1148]    [Pg.1149]   
See also in sourсe #XX -- [ Pg.260 , Pg.268 , Pg.271 ]

See also in sourсe #XX -- [ Pg.259 , Pg.260 ]




SEARCH



Neptunium

© 2024 chempedia.info