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 Periodic System: A Mathematical Approach

2018 ◽  
Author(s):  
Guillermo Restrepo
Keyword(s):  
Periodic System ◽  
Periodic Table ◽  
Chemical Element ◽  
Chemical Elements ◽  
Protein Complexes ◽  
Simple Substance ◽  
System A ◽  
Periodic Law ◽  
Definition Of ◽  
Recent Formulation

The Periodic Table, Despite its near 150 years, is still a vital scientific construct. Two instances of this vitality are the recent formulation of a periodic table of protein complexes (Ahnert et al. 2015) and the announcement of four new chemical elements (Van Noorden 2016). “Interestingly, there is no formal definition of ‘Periodic Table’,” claims Karol (2017) in his chapter of the current volume. And even worse, the related concepts that come into play when referring to the periodic table (such as periodic law, chemical element, periodic system, and some others) overlap, leading to confusion. In this chapter we explore the meaning of the periodic table and of some of its related terms. In so doing we highlight a few common mistakes that arise from confusion of those terms and from misinterpretation of others. By exploring the periodic table, we analyze its mathematics and discuss a recent comment by Hoffmann (2015): “No one in my experience tries to prove [the periodic table] wrong, they just want to find some underlying reason why it is right.” We claim that if the periodic table were “wrong,” its structure would be variable; however the test of the time, including similarity studies, show that it is rather invariable. An approach to the structure of the periodic system we follow in this chapter is through similarity. In so doing we review seven works addressing the similarity of chemical elements accounting for different number of elements and using different properties, either chemical or physical ones. The concept of “chemical element” has raised the interest of several scholars such as Paneth (1962) and is still a matter of discussion given the double meaning it has (see, e.g., Scerri 2007, Earley 2009, Ruthenberg 2009, Ghibaudi et al. 2013, van Brakel 2014, Restrepo & Harré 2015), which is confusing, leading to misconceptions. The two meanings of the concept of chemical element are basic and simple substance. According to Paneth (1962), a basic substance belongs to the transcendental world and it is devoid of qualities, and therefore is not perceptible to our senses.

The Periodic Table: A Very Short Introduction

2019 ◽  
Author(s):  
Eric R. Scerri
Keyword(s):  
Quantum Mechanics ◽  
Atomic Number ◽  
Periodic Table ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Electron Configuration ◽  
Short Introduction ◽  
Atomic Theory ◽  
Recent Advances

The periodic table of elements provides an arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties. The Periodic Table: A Very Short Introduction considers what led to the table’s construction and shows how the deeper meaning of its structure gradually became apparent with the development of atomic theory and quantum mechanics, which underlies the behaviour of all of the elements and their compounds. This new edition celebrates the completion of the seventh period of the table, with the ratification and naming of elements 113, 115, 117, and 118 as nihonium, moscovium, tennessine, and oganesson, and incorporates recent advances in our understanding of the origin of the elements.

What Is A Chemical Element?

2020 ◽  
Keyword(s):  
Periodic Table ◽  
Chemical Element ◽  
Abstract Concept ◽  
International Union ◽  
Applied Chemistry ◽  
Educational Levels ◽  
Unique Position ◽  
Current State ◽  
Element Carbon ◽  
Definition Of

The term “element” is typically used in two distinct senses. First it is taken to mean isolated simple substances such as the green gas chlorine or the yellow solid sulphur. In some languages, including English, it is also used to denote an underlying abstract concept that subsumes simple substances but possesses no properties as such. The allotropes and isotopes of carbon, for example, all represent elements in the sense of simple substances. However, the unique position for the element carbon in the periodic table refers to the abstract sense of “element.” The dual definition of elements proposed by the International Union for Pure and Applied Chemistry contrasts an abstract meaning and an operational one. Nevertheless, the philosophical aspects of this notion are not fully captured by the IUPAC definition, despite the fact that they were crucial for the construction of the periodic table. This pivotal chemical notion remains ambiguous and such ambiguity raises problems at the epistemic, logical, and educational levels. These aspects are discussed throughout the book, from different perspectives. This collective book provides an overview of the current state of the debate on the notion of chemical element. Its authors are historians of chemistry, philosophers of chemistry, and chemists with epistemological and educational concerns.

scholarly journals Role of the periodic table in discovery of new elements

2011 ◽  
Vol 1 (1) ◽  
pp. 1-5 ◽  
Author(s):  
D.C. Hoffman
Keyword(s):  
Periodic Table ◽  
Predictive Power ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Negative Effects ◽  
Current Form ◽  
Future Role ◽  
History Of ◽  
Chemical Techniques

AbstractThis year (2009) marks the 140th Anniversary of Mendeleev's original 1869 periodic table of the elements based on atomic weights. It also marks the 175th anniversary of his birth in Tolbosk, Siberia. The history of the development of periodic tables of the chemical elements is briefly reviewed beginning with the presentation by Dmitri Mendeleev and his associate Nikolai Menshutkin of their original 1869 table based on atomic weights. The value, as well as the sometimes negative effects, of periodic tables in guiding the discovery of new elements based on their predicted chemical properties is assessed. It is noteworthy that the element with Z=101 (mendelevium) was identified in 1955 using chemical techniques. The discoverers proposed the name mendelevium to honor the predictive power of the Mendeleev Periodic Table. Mendelevium still remains the heaviest element to have been identified first by chemical rather than nuclear or physical techniques. The question concerning whether there will be a future role for the current form of the periodic table in predicting chemical properties and aid in the identification of elements beyond those currently known is considered.

HYPOTHESIS ON THE SYNERGISM OF RADIATION AND WATER FILTERS IN THE FORMATION OF BIOOBJECTS

2019 ◽  
Vol 21 (1) ◽  
pp. 53-58
Author(s):  
B.L. Oksengendler ◽  
S.E. Maksimov ◽  
S.U. Norbaev ◽  
L.Yu. Akopyan ◽  
M.V. Konoplyova ◽  
...  
Keyword(s):  
Periodic Table ◽  
Chemical Elements ◽  
Electron Shell ◽  
Living Matter ◽  
Heavy Atoms ◽  
The Third ◽  
Water Filters ◽  
Selection Of ◽  
Electron Shells

The article contains a hypothesis on the dominance of chemical elements of top periods of the Periodic Table in living matter. The idea is that the elements of the third and next periods of the table, in contrast to the first two periods, have larger number of subvalent electron shells. Because of this, ionization of the k-electron shell by radiation (kosmic and terrestrial) in the heavy atoms always leads to the Auger cascade, which causes the destruction of molecular chains. This mechanism can play a role of the radiation filter in the selection of light chemical elements in living matter in addition to the mechanism of hydrolytic filter (G.R. Ivanitskii).

The Dual Conception of the Chemical ElementEpistemic Aspects and Implications for Chemical Education

2020 ◽  
pp. 257-280
Author(s):  
Elena Ghibaudi ◽  
Alberto Regis ◽  
Ezio Roletto
Keyword(s):  
Chemical Analysis ◽  
Atomic Number ◽  
Chemical Element ◽  
Chemical Change ◽  
Chemical Education ◽  
Educational Context ◽  
Material Body ◽  
Chemical Concept ◽  
Definition Of

In the present work, the notion of chemical element is analyzed from the perspective of chemical education. Chemists refer to elements either as the final term of chemical analysis (i.e., simple substances) or as what persists in a chemical change. This duality has deep historical roots and it is sanctioned by IUPAC’s definition of chemical element. Nevertheless, it is inherently contradictory and it may result in deep misunderstandings in the educational context. After discussing the problems raised by the identification of the element with any material body—either macroscopic or microscopic—we analyze a number of definitions of elements, proposed by chemists, epistemologists, and educators. After pointing out the strengths and weaknesses of such definitions, we argue that the chemical element is a unifying chemical concept that designates an abstract category, identified by the atomic number.

scholarly journals Chemistry of the superheavy elements

2015 ◽  
Vol 373 (2037) ◽  
pp. 20140191 ◽  
Author(s):  
Matthias Schädel
Keyword(s):  
Periodic Table ◽  
Nuclear Reactions ◽  
Noble Gas ◽  
Relativistic Quantum ◽  
Chemical Properties ◽  
Relativistic Effects ◽  
Electron Shell ◽  
Heavy Ion ◽  
Superheavy Elements ◽  
Shell Effects

The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently ‘known’ SHEs (11 are officially ‘discovered’ and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe ‘relativistically’ influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models.

scholarly journals Understanding Periodic and Non-periodic Chemistry in Periodic Tables

2021 ◽  
Vol 8 ◽  
Author(s):  
Changsu Cao ◽  
René E. Vernon ◽  
W. H. Eugen Schwarz ◽  
Jun Li
Keyword(s):  
Periodic Table ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Physical Vacuum ◽  
Eyes Open ◽  
The Common ◽  
Nuanced Understanding ◽  
Chemical Conditions ◽  
Aesthetic Concepts ◽  
Secondary Periodicity

The chemical elements are the “conserved principles” or “kernels” of chemistry that are retained when substances are altered. Comprehensive overviews of the chemistry of the elements and their compounds are needed in chemical science. To this end, a graphical display of the chemical properties of the elements, in the form of a Periodic Table, is the helpful tool. Such tables have been designed with the aim of either classifying real chemical substances or emphasizing formal and aesthetic concepts. Simplified, artistic, or economic tables are relevant to educational and cultural fields, while practicing chemists profit more from “chemical tables of chemical elements.” Such tables should incorporate four aspects: (i) typical valence electron configurations of bonded atoms in chemical compounds (instead of the common but chemically atypical ground states of free atoms in physical vacuum); (ii) at least three basic chemical properties (valence number, size, and energy of the valence shells), their joint variation across the elements showing principal and secondary periodicity; (iii) elements in which the (sp)8, (d)10, and (f)14valence shells become closed and inert under ambient chemical conditions, thereby determining the “fix-points” of chemical periodicity; (iv)peculiar elements at the top and at the bottom of the Periodic Table. While it is essential that Periodic Tables display important trends in element chemistry we need to keep our eyes open for unexpected chemical behavior in ambient, near ambient, or unusual conditions. The combination of experimental data and theoretical insight supports a more nuanced understanding of complex periodic trends and non-periodic phenomena.

Lethal Helium Intoxication. Determining the Context, Cause and Time of Death

2018 ◽  
Vol 69 (10) ◽  
pp. 2816-2818
Author(s):  
Andrei Scripcaru ◽  
Anton Knieling ◽  
Cristiana Manea ◽  
Dragos Valentin Crauciuc ◽  
Sofia Mihaela David ◽  
...  
Keyword(s):  
Melting Point ◽  
Atomic Number ◽  
Boiling Point ◽  
Chemical Element ◽  
Chemical Elements ◽  
Extreme Conditions ◽  
Time Of Death ◽  
Gaseous State ◽  
Suicide Rates

Helium is the chemical element with atomic number 2, represented by the symbol He. It is an inert, colorless, odorless, insipid monoatomic gas. It has the lowest boiling point and the lowest melting point among the chemical elements and appears only in gaseous state, except for extreme conditions. The use of helium for suicidal purposes is extremely rare. In Romania, suicide has a frequency of 12 per 100,000 inhabitants, which classifies us in the category of countries with low suicide rates. As methods, men use hanging most often while women use more softer methods such as poisoning. Helium is rarely used for suicidal purposes because it is relatively difficult to obtain. Basically, it is not poisoning in the true sense of the word, but rather the substitution of oxygen with helium, which cannot be carried by hemoglobin, and thus transport asphyxia occurs. At the end of the paper we shall exemplify a case of helium poisoning for suicide purposes, purchased from a cylinder for inflating balloons.

Inorganic Evolution: From Proto-Elements to Extinct Elements

2014 ◽  
Author(s):  
Marco Fontani ◽  
Mariagrazia Costa ◽  
Mary Virginia Orna
Keyword(s):  
Chemical Element ◽  
Chemical Elements ◽  
Point Of View ◽  
Mineral Deposits ◽  
Donets Basin ◽  
Prime Matter ◽  
The Russian Empire ◽  
Definition Of ◽  
The University ◽  
The 19Th Century

Pyotr Nikolaevich Chirvinsky (1880–1955), the eminent Russian geologist, is best known as the founder of the science of meteorology. In the 1920s, Chirvinsky became the director of the Donskoi Polytechnic at Novochercassk. He spent a great deal of time as a consultant for the mines scattered throughout the Russian empire: along the Donets Basin, on the Kola and Crimean peninsulas, on the northeastern slopes of the Caucasus, and in the enormously rich mineral deposits of the Urals. His major objective in this work was to establish connections between the chemical composition of terrestrial minerals and meteorites by studying the quantity of a mineral present in a given sample of rock and the physicochemical conditions leading to its formation. He insisted that meteorites be considered legitimate objects of study in petrology, and because they had been formed in heavenly bodies and not on earth, they might provide clues regarding the formation of elements from primal material. Chirvinsky had predecessors in this way of thinking, as we shall see. The concept of prime matter is very old, coming before the definition of a chemical element, but connected to the idea of the elements. Raymond Lull (ca. 1235–1315), in his book, De Materia, defined the concept of prime matter as an element in potentia in all possible substances. The idea was very acceptable to many alchemists up until the end of the 19th century. In 1800, Jakob Joseph Winterl (1732?–1809) was a famous physician and professor at the University of Nagyszombat, in present-day Hungary. He developed a vitalistic and dualistic concept that was, from a certain point of view, anti-Enlightenment, according to which all of the chemical elements would have originated from two immaterial principles: one male, andronia, and the other female, thelyke. Although Winterl’s speculations may have been based on doubtful or misinterpreted experimental evidence, many German chemists accepted his theory. The physicist Heinrich Pfaff (1773–1852) embraced Winterl’s theory with enthusiasm, as did the pharmacist Johann Friedrich Westrumb (1751–1819) who propagated the concepts of thelyke and andronia. The first problems occurred when Winterl was unsuccessful in experimentally proving his theory.

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