scholarly journals The stark effect for xenon

1933 ◽  
Vol 139 (838) ◽  
pp. 416-435 ◽  
Keyword(s):  
External Field ◽  
Quantum Number ◽  
Stark Effect ◽  
Principal Quantum Number ◽  
Principal Series ◽  
Quantum Mechanical ◽  
Rare Gases ◽  
Normal Position ◽  
High Eccentricity ◽  
Mechanical Explanation

Many leading features in the Stark effect are best illustrated by studies in the spectra of the rare gases. In each spectrum at least one phase of the Stark effect stands out prominently. Thus in helium the Stark types for singlet lines are most clearly revealed, while in neon an analogue of the Paschen-Back effect makes its appearance, together with some departures from the normal Stark patterns for parhelium. The present experiments with xenon constitute evidence in support of a quantum-mechanical explanation of the origin of Stark displacements and reveal new features concerning the nature of Stark patterns. It was first observed in Stark displacements, in helium that sharp and principal series lines were displaced very little in comparison with diffuse series lines. The relatively small displacements received an early explanation on the grounds of an atomic model in which the s -and p -terms corresponded to electron orbits of high eccentricity which revolve rapidly in their planes. This action prevented the external field from producing an appreciable shift of the electrical centre from its normal position in the nucleus. Since the excess of the term in question over the hydrogen term of the same principal quantum number (the so-called hydrogen difference) measured the speed of revolution of the orbit, it seemed clear that hydrogen differences should serve as valuable guides to probable Stark displacements. Up to the present well organised data have appeared to support this view.

scholarly journals Application of quantum mechanics to the stark effect in helium

1927 ◽  
Vol 117 (776) ◽  
pp. 137-163 ◽  
Keyword(s):  
Quantum Mechanics ◽  
External Field ◽  
Electric Field ◽  
Quantum Number ◽  
Stark Effect ◽  
Azimuthal Quantum Number

Many interesting features of the Stark-effect may be seen with unusual clearness in the arc spectra of helium, and these we shall mention very briefly before referring to the theory. The fact that an electric field applied to the source will bring out the combination lines 2 p — mp was discovered by Koch in 1915. Since that time many investigators have shown by Lo Surdo’s method that a moderate external field is sufficient to remove all restrictions with regard to changes in the azimuthal quantum number.

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
Keyword(s):  
Chemical Shift ◽  
Quantum Number ◽  
Principal Quantum Number ◽  
Valence Electrons ◽  
Phenyl Compounds ◽  
Atomic Parameters

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.

scholarly journals CONTRADICTION TO THE TABLE OF D. I. MENDELEEV AND THEIR ELIMINATION

2021 ◽  
Vol 2 (446) ◽  
pp. 14-21
Author(s):  
N.К. Akhmetov ◽  
G.U. Ilyasova ◽  
S. K. Kazybekova
Keyword(s):  
Quantum Number ◽  
Periodic Table ◽  
Chemical Elements ◽  
Principal Quantum Number ◽  
Quantum States ◽  
Outer Electron ◽  
New Approach ◽  
Electronic Configurations ◽  
New Formula ◽  
Electron Shells

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).

The Lithium Group

2010 ◽  
Author(s):  
George K. Schweitzer ◽  
Lester L. Pesterfield
Keyword(s):  
Charge Density ◽  
Quantum Number ◽  
Oxidation State ◽  
Periodic Table ◽  
Alkali Metals ◽  
Principal Quantum Number ◽  
Horizontal Line ◽  
Outer Electron ◽  
Aqueous Chemistry ◽  
Figure Legend

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+.

scholarly journals Radio Spectroscopy of Planetary Nebulae

1978 ◽  
Vol 76 ◽  
pp. 127-128
Author(s):  
Eric J. Chaisson
Keyword(s):  
Stark Effect ◽  
Principal Quantum Number ◽  
Planetary Nebulae ◽  
Radio Continuum ◽  
Radio Lines ◽  
Ion Temperature ◽  
Radio Recombination Line ◽  
Ngc 7027 ◽  
Optical Line ◽  
Ion Impact

The H110α radio recombination line has been observed toward the planetary nebulae NGC 7027, IC 418, and NGC 6543 in order to ascertain the physical characteristics of the bulk nebular gas. The observations of NGC 7027 confirm the earlier findings of Chaisson and Malkan (Ap.J., 210, 108, 1976) and Churchwell, Terzian and Walmsley (A&A, 48, 331, 1976) who reported evidence for a substantial increase in linewidth with principal quantum number. Attributed to electron-ion impact broadening (Stark Effect), the observations imply an electron density Ne ≃ 50,000/cm3. The LTE-derived electron-ion temperature Te ≃ 18,000°K agrees reasonably well with most radio-line analyses, as well as with previous analyses of the radio continuum, of forbidden optical line ratios, and of optical recombination lines and their associated continuum. IC418's HllOa line is also wider than radio lines observed at higher frequencies, suggesting a Stark Effect consistent with Ne < 20,000/cm3; NGC 6543 shows no appreciable line broadening, providing an upper limit to the density Ne < 10,000/cm3. The LTE-derived Te values for IC 418 and NGC 6543 are approximately 14,000 and 7000°K, reasonably consistent with those found by other techniques. On the basis of this and other recent studies, I suggest that the bulkemission in the Hnα recombination lines observed to date, 77 < n < 111, can be explained by a simple model of optically thin planetary nebular gas largely homogeneous in temperature and in density, and only slightly removed from LTE.

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