Uranium ionization energy

For vanadium and chromium the first ionization energies are much lower than the first ionization energies of phosphorus and sulphur, respectively. This explains the high heats of formation of VC13 and CrCl3. In uranium, the tetravalent state is more stable than that in tungsten because uranium as an actinide has a different electron configuration. 

Laser requirements. In order to utilize photons efficiently, absorption by should be selective. A absorption line should be found that (1) occurs at a frequency at which does not absorb, and (2) has a high absorption cross section, to reduce the light path needed for efficient use of photons. Because the isotope shift between U and 17 absorption frequencies is of the order of 1 in 50,000, the first requirement calls for use of a very narrow absorption line. Because the absorption lines for transitions in which uranium is ionized are very broad, it is necessary to ionize the atoms in two or more steps, in which the first step is selective excitation of to an energy level below the uranium ionization potential of... 

Coulomb explosion to yield and F. This inherent stability is a result of the modest ionization energies of U and the favorable U—F bonding interactions. This conclusion is all the more remarkable given that the formal charge on uranium in UF is +3.4 due to the electron-withdrawing fluorine ligands. 

K. Rashid, M. Z. Saadi, and M. Yasin, Dirac-Fock total energies, ionization energies, and orbital energies for uranium ions (U I to U XCII), At. Data Nucl. Data Tables 40, 365 (1988). 

Spark source (SSMS) and thermal emission (TEMS) mass spectrometry are used to determine ppb to ppm quantities of elements in energy sources such as coal, fuel oil, and gasoline. Toxic metals—cadmium, mercury, lead, and zinc— may be determined by SSMS with an estimated precision of 5%, and metals which ionize thermally may be determined by TEMS with an estimated precision of 1% using the isotope dilution technique. An environmental study of the trace element balance from a coal-fired steam plant was done by SSMS using isotope dilution to determine the toxic metals and a general scan technique for 15 other elements using chemically determined iron as an internal standard. In addition, isotope dilution procedures for the analysis of lead in gasoline and uranium in coal and fly ash by TEMS are presented. 

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