Various forms of the periodic table including the left-step table, the regularization of atomic number triads and first-member anomalies

ChemTexts ◽  
2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Eric R. Scerri
Keyword(s):  
Atomic Number ◽  
Periodic Table

scholarly journals CHEMICAL CHARACTER AND PHYSIOLOGICAL ACTION OF THE POTASSIUM ION

1920 ◽  
Vol 3 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Jacques Loeb
Keyword(s):  
Atomic Number ◽  
Sea Urchin ◽  
Periodic Table ◽  
Chemical Behavior ◽  
Physiological Action ◽  
General Chemical ◽  
Li Ion ◽  
Chemical Character ◽  
Cs Ions ◽  
Salt Action

1. It is shown that the NH4 ion acts in cases of antagonism on the egg of Fundulus more like the K ion than the Na ion; this corresponds to the fact that in its general chemical behavior the NH4 ion resembles the K ion more closely than the Na ion. 2. It is shown that the tolerance of sea urchin eggs towards the Li ion can be increased 500 per cent or more if at the same time a certain amount of Na ion is replaced by K, Rb, or Cs ions. Since in the periodic table Na occupies a position between K and Li it is inferred that the Li and K ions deviate in their physiological action in the opposite direction from the Na ion. 3. These data indicate that the behavior of the K ion in antagonistic salt action (which forms the basis of the physiologically balanced action of ions) is due to its purely chemical character, i.e. its position in the periodic table or rather to its atomic number, and not to those explosions in its nucleus which give rise to a trace of radioactivity.

Discovery of the Element With Atomic Number Z = 118 Completing the 7th Row of the Periodic Table

2017 ◽  
Author(s):  
Paul J. Karol ◽  
Robert C. Barber ◽  
Bradley M. Sherrill ◽  
Emanuele Vardaci ◽  
Toshimitsu Yamazaki
Keyword(s):  
Atomic Number ◽  
Periodic Table

Heavy, Superheavy . . . Quo Vadis?

2018 ◽  
Author(s):  
Paul J. Karol
Keyword(s):  
Atomic Number ◽  
Periodic Table ◽  
Chemical Element ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Superheavy Element ◽  
Electron Shell ◽  
Heavy Elements ◽  
Quo Vadis ◽  
Definition Of

Uranium was Discovered in 1789 by the German chemist Martin Heinrich Klaproth in pitchblende ore from Joachimsthal, a town now in the Czech Republic. Nearly a century later, the Russian chemist Dmitri Mendeleev placed uranium at the end of his periodic table of the chemical elements. A century ago, Moseley used x-ray spectroscopy to set the atomic number of uranium at 92, making it the heaviest element known at the time. This chapter will deal with the quest to explore that limit and heavy and superheavy elements, and provide an update on where continuation of the periodic table is headed and some of the significant changes in its appearance and interpretation that may be necessary. Our use of the term “heavy elements” differs from that of astrophysicists who refer to elements above helium as heavy elements. The meaning of the term “superheavy” element is still not exactly agreed upon and has changed over the past several decades. “Ultraheavy” is occasionally used. Interestingly, there is no formal definition of “periodic table” by the International Union of Pure and Applied Chemistry (IUPAC) in their glossary of definitions: the “Gold Book.” But there are plenty of definitions in the general literature—including Wikipedia, the collaborative, free, internet encyclopedia which calls the “periodic table” a “tabular arrangement of the chemical elements, organized on the basis of their atomic numbers, electron configurations (electron shell model), and recurring chemical properties. Elements are presented in order of increasing atomic number (the number of protons in the nucleus).” IUPAC’s first definition of a “chemical element” is: “A species of atoms; all atoms with the same number of protons in the atomic nucleus.” Their definition of atom: “the smallest particle still characterizing a chemical element. It consists of a nucleus of positive charge (Z is the proton number and e the elementary charge) carrying almost all its mass (more than 99.9%) and Z electrons determining its size.”

The Three-letter Element Symbols:

2016 ◽  
Vol 38 (2) ◽  
Author(s):  
Lars Öhrström ◽  
Norman E. Holden
Keyword(s):  
High School ◽  
Atomic Number ◽  
Periodic Table

AbstractWhen Lars Öhrström started paying real attention to chemistry, during his high school years in the early 1980s, the three-letter symbols then designating any element with atomic number higher than 103 seemed like a permanent fixture to the periodic table in the chemistry classroom. In the following years, he learned that they were only temporary placeholders for elements that fulfilled the criteria of “being discovered” but where, for unclear reasons, a name had not yet been agreed.

The interpolation of atomic fields

1955 ◽  
Vol 51 (4) ◽  
pp. 693-701 ◽  
Author(s):  
E. Cicely Ridley
Keyword(s):  
Wave Function ◽  
Atomic Number ◽  
Periodic Table ◽  
Published Data ◽  
Parameter Method ◽  
Screening Constant ◽  
Unknown Structure ◽  
Good For ◽  
Two Parameters ◽  
Two Parameter

ABSTRACTZ(nl; r) is the contribution to Z(r) from an electron in the (nl) wave function. The Z(nl; r) vary systematically with atomic number and, as N becomes large, tend to the corresponding hydrogen-like functions, ZH(nl; r). A two-parameter method of fitting the Z(nl; r) to the ZH(nl; r) is described. This involves a ‘screening constant’ and a ‘slope constant’, both of which are defined. From published data, the two parameters have been obtained as functions of atomic number. The parameters for an unsolved atom can then be found by interpolation and approximate Z(nl; r) derived by appropriate adjustment of the functions for the nearest atom in the periodic table for which they are known. The method has been tested by interpolating for the (3d) function between Cu+ and Rb+ and by preparing estimates of the Z(nl; r) for the unknown structure Mo+. The results were good for all but Z(4d; r) for Mo+, where the number of values of the screening and slope constants already known was insufficient for reliable interpolation.

6. Physics invades the periodic table

2019 ◽  
pp. 73-84
Author(s):  
Eric R. Scerri
Keyword(s):  
Nuclear Structure ◽  
Atomic Number ◽  
Periodic Table ◽  
Atomic Weight ◽  
Ernest Rutherford ◽  
Frederick Soddy ◽  
The Impact

‘Physics invades the periodic table’ assesses the impact of key discoveries in physics on the understanding of the periodic table. Ernest Rutherford provided evidence for the nuclear structure of atoms, and also determined that the charge of an atom is equal to half its atomic weight. Anton van den Broek linked this principle to the number of protons in a nucleus, thus devising the notion of atomic number. Henry Moseley quantified this principle, and used it to show exactly how many elements would fill the gaps in the periodic table. Radioactive experiments created new forms of elements with different weights but the same charge, which Frederick Soddy identified as isotopes.

The Actinoid Metals

2010 ◽  
Author(s):  
George K. Schweitzer ◽  
Lester L. Pesterfield
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Oxidation State ◽  
Atomic Number ◽  
Relative Abundance ◽  
Neutron Capture ◽  
Periodic Table ◽  
Valence Electron ◽  
Oxidation States

The elements making up the Actinoid Metals are those with atomic numbers from 89 through 103: Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, and Lr. The name is meant to parallel the lanthanoids. They are generally abbreviated as An. Their valence electron structures are 7s26d0−25f0−14. These elements resemble the lanthanoids somewhat, but they have a much wider variation in oxidation states. Nor do they resemble each other to the extent that the lanthanoids do, this being a result of the oxidation state variations. Ac resembles La greatly, but Th, Pa, and U resemble their vertical congeners (Hf, Ta, W) more than they resemble Ce, Pr, and Nd. From Np onwards, the resemblance to the lanthanoids increases such that by Am, the actinoid elements are behaving very similarly, showing a predominant oxidation state of III. All of this occurs because the 7s, 6d, and 5f levels are much closer in energy than the 6s, 5d, and 4f levels. Table 18.1 lists the actinoids with several of their pertinent characteristics. No stable isotopes of any of these elements exist, the last element in the Periodic Table with a stable isotope being Bi (Bi-209). However, some of the An elements have isotopes with very long half lives, which means that they are found in nature in relative abundance, most notably as Th-232 (1010.1 years), U-235 (108.8 years), and U-238 (109.7 years). Others are products of the decay of the above isotopes, so even though they are shorter lived, they persist in nature since they are continually being produced. The most important nuclides of this type are Ac-227 (21.8 years) and Pa-231 (104.5 years), both coming from U-235 decay. In U ores, very small amounts of Np-237 (106.3 years), Np-239 (2.4 days), and Pu-239(104.3 years) arise from the interaction of neutrons with U isotopes. Isotopes of the elements beyond U are produced artificially, Np and Pu by neutron capture by U, Am and Cm by multiple neutron capture by Pu, and elements beyond Cm by further neutron captures or bombardment of lower atomic number actinoids with ions of He, B, C, N, or O.

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