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.

Oganesson, Where Art Thou?

2018 ◽  
Vol 40 (4) ◽  
pp. 27-27
Author(s):  
Daniel Rabinovich
Keyword(s):  
Experimental Data ◽  
Periodic Table ◽  
Noble Gas ◽  
Press Release ◽  
International Union ◽  
Applied Chemistry

Abstract In a press release dated 30 December 2015, the International Union of Pure and Applied Chemistry (IUPAC) announced that a thorough review by independent experts of the experimental data available for the syntheses of elements 113, 115, 117, and 118 has been concluded, and that the discovery of the four elements completing the 7th row of the periodic table was confirmed. The elemental names and symbols proposed shortly thereafter by the corresponding discovery teams met the criteria prescribed by IUPAC for naming new elements, and nihonium (Nh), moscovium (Mc), tennessine (Ts), and oganesson (Og), became permanent within a few months. As such, the ending of the name of element 118 and its location in the periodic table, below radon in group 18, are consistent with the assumption that oganesson could be regarded as a noble gas.

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.

Cesium kupletskite renamed kupletskite-(Cs)

2007 ◽  
Vol 71 (3) ◽  
pp. 365-367 ◽  
Author(s):  
P. Bayliss
Keyword(s):  
Chemical Element ◽  
Mineral Species ◽  
Single Word ◽  
International Union ◽  
Applied Chemistry

AbstractCesium kupletskite has been renamed kupletskite-(Cs) with the approval of the IMA Commission on New Minerals, Nomenclature and Classification, because the name of a mineral species should be a single word and the International Union of Pure and Applied Chemistry spelling is caesium. The presence or absence of parentheses around the suffix chemical-element is discussed. The advantages of the chemical-element suffix nomenclature are stated.

Biomarkers of Acromegaly and Growth Hormone Action

2020 ◽  
Vol 27 (12) ◽  
pp. 1231-1245
Author(s):  
Filippo Maffezzoni ◽  
Teresa Porcelli ◽  
Andrea Delbarba ◽  
Letizia Pezzaioli ◽  
Carlo Cappelli ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Biological Markers ◽  
Clinical Care ◽  
Hormone Deficiency ◽  
Surrogate Outcomes ◽  
Current State ◽  
Growth Hormone Action ◽  
Igf I ◽  
Definition Of

: Biological markers (biomarkers) play a key role in drug development, regulatory approval and clinical care of patients and are linked to clinical and surrogate outcomes. : Both acromegaly and Growth Hormone Deficiency (GHD) are pathological conditions related to important comorbidities that, in addition to having stringent diagnostic criteria, require valid markers for the definition of treatment, treatment monitoring and follow-up. GH and insulin-like growth factor-I (IGF-I) are the main biomarkers of GH action in children and adults while, in acromegaly, both GH and IGF-I are established biomarkers of disease activity. : However, although GH and IGF-I are widely validated biomarkers of GHD and acromegaly, their role is not completely exhaustive or suitable for clinical classification and follow-up. Therefore, new biological markers for acromegaly and GH replacement therapy are strongly needed. : The aim of this paper is to review and summarize the current state in the field pointing out new potential biomarkers for acromegaly and GH use/abuse.

Minority Presidents in a Coalitional World

2018 ◽  
Author(s):  
Paul Chaisty ◽  
Nic Cheeseman ◽  
Timothy J. Power
Keyword(s):  
Coalition Formation ◽  
Cost Minimization ◽  
Analytical Framework ◽  
System Level ◽  
Current State ◽  
Key Concepts ◽  
Definition Of

This chapter summarizes the main parameters of coalitional presidentialism and the key concepts, definitions, explanatory frameworks, indicators, and propositions. It summarizes our understanding of coalitional presidentialism; the distinction between coalition formation and maintenance; the definition of coalitions; the multidimensional understanding of coalition management (the ‘presidential toolbox’); and an analytical framework that emphasizes the motivation of presidents to achieve cost minimization under constraints determined by system-level, coalition-level, and conjunctural factors. It also summarizes our main empirical findings: (1) the characteristics of presidential tools, (2) the substantive patterns of their deployment, (3) the factors that shape the costs of using these tools, (4) the actual (observed) costs of using them, and (5) the potential for imperfect substitutability of these tools. Finally, it concludes with some reflections on the current state of the research on comparative presidentialism.

scholarly journals Organic–Inorganic Hybrid Materials

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 86
Author(s):  
Jesús-María García-Martínez ◽  
Emilia P. Collar
Keyword(s):  
Hybrid Materials ◽  
Hybrid Material ◽  
International Union ◽  
Applied Chemistry ◽  
Inorganic Hybrid ◽  
Organic Components ◽  
Intimate Mixture ◽  
Inorganic Components

According to the IUPAC (International Union of Pure and Applied Chemistry), a hybrid material is that composed of an intimate mixture of inorganic components, organic components, or both types of components which usually interpenetrate on scales of less than 1 μm [...]

WoCoVA consensus on the clinical use of in-line filtration during intravenous infusions: Current evidence and recommendations for future research

2021 ◽  
pp. 112972982198916
Author(s):  
Ton Van Boxtel ◽  
Mauro Pittiruti ◽  
Annemarie Arkema ◽  
Patrick Ball ◽  
Giovanni Barone ◽  
...  
Keyword(s):  
Potential Benefit ◽  
Scientific Evidence ◽  
Venous Access ◽  
Current Evidence ◽  
Future Research ◽  
Global Awareness ◽  
Current State ◽  
Intravenous Infusions ◽  
Proper Definition ◽  
Definition Of

The need for filtering intravenous infusions has long been recognized in the field of venous access, though hard scientific evidence about the actual indications for in-line filters has been scarce. In the last few years, several papers and a few clinical studies have raised again this issue, suggesting that the time has come for a proper definition of the type of filtration, of its potential benefit, and of its proper indications in clinical practice. The WoCoVA Foundation, whose goal is to increase the global awareness on the risk of intravenous access and on patients’ safety, developed the project of a consensus on intravenous filtration. A panel of experts in different aspects of intravenous infusion was chosen to express the current state of knowledge about filtration and to indicate the direction of future research in this field. The present document reports the final conclusions of the panel.

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