Electron configuration of actinides

Table 2. Comparison of the electronic configurations of actinide metals derived by Fournier and by Johansson ...

Electronic configurations of actinide atoms, ions, and their common oxides. 

TABLE 2 Ground-State (GS) and Selected Excited-State Electronic Configurations of Actinide Cations ... 

There is no single best form of the periodic table since the choice depends on the purpose for which the table is used. Some forms emphasize chemical relations and valence, whereas others stress the electronic configuration of the elements or the dependence of the periods on the shells and subshells of the atomic structure. The most convenient form for our purpose is the so-called long form with separate panels for the lanthanide and actinide elements (see inside front cover). There has been a lively debate during the past decade as to the best numbering system to be used for the individual... 

THE ELECTRON CONFIGURATIONS OF GASEOUS ACTINIDE AND LANTHANIDE ATOMS... 

The concept of valence developed in the preceding section is the basis of the first correlations aiming at a global theory of the actinide metallic bond. These correlations were established between the atomic volumes of actinide elemental metals, and the electronic configuration of the actinide atoms Their aim was to provide a general theory of actinides (i.e. to give an answer to the questions i. and ii. of Sect. A.I.l.) within the framework of a simple model of the metallic bond. 

The energy level values of the lowest spectroscopic term of the electronic configuration of lanthanide as well as actinide atoms, were tabulated by Brewer. Such tables are very useful for phenomenological correlations concerning actinide metals (see Chap. C). From these tables one can obtain Table 1 giving the ground state and the first excited level of the actinide atoms as well as of the lanthanide atoms for comparison ... 

Table 8.6 The outer electronic configurations of the actinide elements the atoms all possess a 7s2 pair of electrons...

Electronic Structure. Measurements of paramagnetic susceptibility, paramagnetic resonance, light absorption, fluorescence, and crystal structure, in addition to a consideration of chemical and other properties, have provided a great deal of information about the electronic configuration of the aqueous actinide ions in which the electrons arc in the 5/ shell. There are exceptions, such as U2S3, and subnormal compounds, such as TI12S3, where 6d electrons are present. 

EINSTENIUM. CAS 7429-92-71. Chemical element symbol Es, at. no. 99. at. wt. 254 (mass number of the most stable isotope), radioactive metal of the Actinide series, also one of the Transuranium elements. Both einsteinium and fermium were formed tit a thermonuclear explosion that occurred in the South Pacific in 1952. The elements were identified by scientists from the University of California s Radiation Laboratory- the Argonnc National Laboratory, and the I. os Alamos Scientific Laboratory. It was observed that very heavy uranium isotopes which resulted from the action of the instantaneous neutron dux on uranium (contained in the explosive device) decayed to form Es and Fm. The probable electronic configuration of Es is... 

The first attempts to record the Bk(IV) solution absorption spectrum were hindered by the presence of cerium impurities (92). The positions of the Bk(IV) absorption bands, superimposed on the strong Ce(IV) bands, suggested the assignment of Sf7 for the electronic configuration of Bk(IV), in agreement with the actinide hypothesis. 

This effect originates in the various f electron configurations of lanthanides and actinides. This effect is based on the correlation observed between the full pattern of the effect and the sequence of values of the L quantum number [52]. The correlation consists of the occurrence of the same double symmetry in (a) the series of L quantum number values of the ground terms of f element ions and (b) the sequence of relatively stabilized or destabilized f electron configurations (i.e.) the double-double effect. Accordingly... 

Table 9.3 Electron configurations of the actinides and their ions ...

Table 3 Valence level electronic configuration of the actinides in the gas phase ...

The electron configurations of the actinides in the gas phase are listed in Table 14.3. Whereas in the case of the lanthanides only up to two f electrons are available for chemical bonding, in the case of the actinides more than two f electrons may be engaged in chemical bonds (e.g. all the electrons in compounds of FT(VI) and Np(VII)). This is due to the relatively low differences in the energy levels of the 5f and 6d electrons up to Z 95 (Am). However, these differences increase with Z and the chemistry of elements with Z > 96 becomes similar to that of the lanthanides. The special properties of the actinides are evident from their oxidation states, plotted in Fig. 14.12 as a function of the atomic number. In contrast to the lanthanides, a tendency to form lower oxidation states is observed with the heavier actinides. The... 

Apart from the lanthanide and actinide trifluorides all of the transition-metal trifluoride structures known show the metal atom to be six-co-ordinated in fluorine. Indeed in only one other case, that of manganese tri-fluoride, is there an appreciable distortion from octahedral symmetry. The distortions may be correlated with the electronic configurations of the metal atoms. Table 4 shows that, in the first transition series tri-... 

Why are the nuclear structures of the actinides more important than the electron configurations of the actinides ... 

How do the electron configurations of the lanthanide and actinide elements differ from the electron configurations of the other transition metals ... 

Figure 9.2 gives electronegativity values for the lanthanides and actinides. Notice that the values for both series of inner transition elements do not vary a great deal. Explain why you might have predicted this on the basis of the electron configurations of these elements. (Chapter 7)... 

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