Zur Kenntnis der Dihalogen-tris-(4-dimethylamino-phenyl)-Verbindungen von Phosphor, Arsen, Antimon und Wismut / Dihalogeno-tris- (4-dimethylamino-phenyl) -Compounds of Phosphorus, Arsenic, Antimony, and Bismuth

1972 ◽  
Vol 27 (6) ◽  
pp. 591-595 ◽  
Author(s):  
Jörn-Michael Keck ◽  
Günter Klar

The synthesis of the dihalogeno-tris-(4-dimethylamino-phenyl)-compounds Ar2EX2 (E = P, As, Sb; X = Cl, Br, J and E = Sb, X = F; E = Bi, X = Cl) is described. A generally valid correlation between the chemical shift of the n.m.r. signal of an atom and the atomic parameters electronegativity and principal quantum number of valence electrons is deduced.

Author(s):  
N.К. Akhmetov ◽  
G.U. Ilyasova ◽  
S. K. Kazybekova

The article discusses a new approach to the formation of periods of the Periodic Table of Mendeleev. With the help of the new formula and the first proposed quantum states of the outer electron shells of atoms of chemical elements, the periods of the periodic table are reformatted. It is supposed to reduce the number of periods in the table by introducing the corresponding sub-periods. This is confirmed by the material given in the article. The following description of the order of formation of electron layers is proposed: the principal quantum number (n), then the newly proposed quantum states of electrons («first» and «second»), which in turn constitute the electronic configurations of sub-periods in periods, and only then the remaining quantum orbitals (s, p, d and f).


Author(s):  
George K. Schweitzer ◽  
Lester L. Pesterfield

The elements which constitute Group 1 of the Periodic Table are known as the alkali metals. They are lithium Li, sodium Na, potassium K, rubidium Rb, cesium Cs, and francium Fr. (Sometimes the NH4+ ion is included among these since it resembles K+ or Rb+ in many of its reactions.) All six of the elements have atoms characterized by an outer electron structure of ns1 with n representing the principal quantum number. The elements exhibit marked resemblances to each other with Li deviating the most. This deviation is assignable to the small size of Li which causes the positive charge of Li+ to be concentrated, that is, the charge density is high. All of the elements exhibit oxidation numbers of 0 and I, with exceptions being rare, such that their chemistries are dominated by the oxidation state I. The six metals are exceptionally reactive, being strong reductants, reacting with HOH at all pH values to give H2 and M+, and having hydroxides MOH which are strong and soluble. Ionic sizes in pm for the members of the group are as follows: Li (76), Na (102), K (139), Rb (152), Cs (167), and Fr (180). The E° values for the M+/M couples are as follows: Li (−3.04 v), Na (−2.71 v), K (−2.93 v), Rb (−2.92 v), Cs (−2.92 v), and Fr (about −3.03 v). a. E–pH diagram. The E–pH diagram for 10−1.0 M Li is presented in Figure 5.1. The figure legend provides an equation for the line that separates Li+ and Li. The horizontal line appears at an E value of −3.10 v. Considerably above the Li+/Li line, the HOH ≡ H+/H2 line appears, which indicates that Li metal is unstable in HOH, reacting with it to produce H2 and Li+. Note further that Li+ dominates the diagram reflecting that the aqueous chemistry of Li is largely that of the ion Li+.


2007 ◽  
Vol 85 (5) ◽  
pp. 551-561 ◽  
Author(s):  
E Yu. Korzinin ◽  
V G Ivanov ◽  
S G Karshenboim

We present new results on various asymptotics for the Uehling contribution to the energy levels in atomic states in hydrogen-like atoms that have a principal quantum number n with a high value. The results may be applied to conventional atoms (with an orbiting electron) as well as to muonic, pionic, antiprotonic, and other exotic atoms.PACS Nos.: 36.10.Gv, 31.30.Jv


1958 ◽  
Vol 28 (2) ◽  
pp. 364-365 ◽  
Author(s):  
L. Leifer ◽  
F. A. Cotton ◽  
J. R. Leto

1948 ◽  
Vol 1 (3) ◽  
pp. 289
Author(s):  
RG Giovanelli

The populations of the hydrogen substates of principal quantum number 1, 2, or 5 are calculated for a range of electron concentrations from 108 to 1013 per cc. and electron temperatures from 7.5 x 103 to 1.0 x 105 �K., in the presence of radiation from a black body at a temperature of 5x 103 �K., diluted by a factor of 1, 0.5, or 0.


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