Modern Periodic Table Research Articles

Selective extraction and recovery of rare earth elements from coal fly ash by carboxylated mesoporous carbon

The separation of Rare Earth Elements (REEs) from non-conventional sources is very critical to maintain the supply-chain balance of REEs in the Western world. Despite Coal Fly Ash (CFA) being designated as a prominent non-conventional source of REEs and several studies have reported on the extraction of REEs from CFA, the selectivity of REEs with respect to non-REEs in the CFA has never been reported. In this work, for the time, we have reported the selectivity of REEs over non-REEs using carboxylated mesoporous carbon (CMC) as the sorbent. The CMC was produced by carboxylating the soft-templated mesoporous carbon and then it was characterized successfully for porosity, FTIR, and SEM-EDX. The leachate produced from REEs contains 16 REEs and 20 non-REEs from groups 1 through 3 and 6 through 15 of the modern periodic table. The REEs were extracted within 80–90% in the 3 cycles along with the elements from groups of 1,3, 5, 8, and 11. Although a few other elements were also extracted, the values of the distribution coefficient confirmed that the CMC has a much higher affinity towards REEs except the non-REEs from groups 1 and 3. In the recovery mode, the REEs were recovered in the range of 20–100%, and heavier REEs demonstrated a better recovery. The recovery percent of non-REEs was also much lower compared to that of REEs, except for the elements from groups 3, 8, and 11. The non-REEs from group 3 demonstrated the highest competition, which can be attributed to the fact the REEs also belong to the same group of the periodic table. The ratio of extracted and recovered REEs over non-REEs was always greater than unity, suggesting that the CMC was selective towards REEs over non-REEs in extraction and recovery. The overall results suggest that CMC can potentially be used for selective extraction and recovery of REEs from coal fly ash.

Exploring the Trends and Patterns in Periodicity of Elements: from Mendeleev to Modern Periodic Table

Dmitri Mendeleev created the periodic table in 1869, and it has undergone significant modifications to become an essential tool in chemical science today. This abstract provides an informative summary of the evolution of periodic trends and patterns, from Mendeleev's work to the latest complexities in the current periodic table. The first step towards comprehending the periodicity of elements was Mendeleev's periodic table, which he offered as a means of classifying elements according to their atomic weights and chemical behaviours. The periodic table underwent additions and modifications during the ensuing decades as atomic theory and experimental methods advanced. Instead of focusing on atomic weights, the current periodic law is concerned with the precise atomic number. Henry Moseley's discovery of the atomic number altered the elemental positions. This modification allowed for a deeper examination of periodic trends between elements by clarifying elemental relationships. Periodic trend analysis takes into account several characteristics, such as atomic radius, ionisation energy, electron affinity, and electronegativity. This is evident from the fact that each group of elements, ranging from noble gases to alkali metals, has distinct tendencies in both physical and chemical properties. We gathered the necessary materials for this review from a variety of reliable sources, including physical chemistry by K. K. Sharma, inorganic chemistry by J. D. Lee, and other published works. In conclusion, Mendeleev's table's evolution to its current state demonstrates that scientists have been addressing the issue for many generations. The periodic table is still a vital tool for classifying and evaluating the wide range of elements and their characteristics, although there are still many uncharted territories in chemistry. Keywords: electronic configuration, group analysis, periodic trend, periodicity, atomic number, and quantum physics.

Effect of Chromium on Human-Health: A Review

This review presents the health effects of chromium on the living organism based on previous studies. Chromium (Cr) belongs to the d-block element in the modern periodic table. Chromium has a wide range of oxidation states ranging from -2 to +6. Chromium mostly exists in the environment as trivalent (Cr3+) and hexavalent (Cr6+) states. Both trivalent and hexavalent states of chromiums are derived from the industrial effluents. Ingestion, dermal contact, and inhalation are the most common routes through which chromium enters the human body. Ion chromatography inductively coupled plasmamass spectrometry (IC-ICP-MS) is mostly used for the speciation analysis of metals. Hexavalent chromium is highly soluble and mobile in alkaline and slightly acidic soils, whereas trivalent chromium is less soluble, adheres to the coarse material on the soil, and precipitates as Cr(III) hydroxide. Hexavalent chromium is more detrimental as compared to trivalent chromium. The detrimental effects of chromium are bronchial asthma, lung cancer, nasal ulcers, skin allergies, carcinogenicity, and genotoxicity. To protect from these adverse effects, WHO has suggested a provisional guideline value of chromium as 0.05 mg/L until further information is available and revalued.

On the position of La, Lu, Ac and Lr in the periodic table: a perspective

The periodic table of elements, organised as blocks of elements that contain similar properties, occupies a central role in chemistry. However, the position of some of the elements in the periodic table is a debate that has been ensuing over the past one and a half long centuries. Particularly, the positions of lanthanum (La), lutetium (Lu), actinium (Ac) and lawrencium (Lr) in the periodic table have been quite controversial. Different kinds of studies carried out by various research groups have yet left the fate of these elements undecided as the results of these investigations suggested that these elements could potentially be placed in the d-block, p-block or all four in the f-block. Our recent work looked into this question from a new perspective, involving encapsulation of La, Lu, Ac and Lr into Zintl ion clusters, Pb122− and Sn122−. These clusters were chosen as they provide a fitting environment for the determination of structural, thermodynamic and electronic properties of the encapsulated species. Various results that have been evaluated and subsequently analysed (Joshi et al. in Phys. Chem. Chem. Phys. 20:15253–15272, 2018) in order to seek out similarities and differences for making justified conclusions about the placement of all these four elements in the periodic table are the subject matter of this review article. This review highlights a unique methodology wherein Ln and An encapsulated Pb122− and Sn122− clusters provided in-depth insights on the long-drawn controversy: positions of lutetium, lawrencium, lanthanum and actinium in the modern periodic table. Electronic, thermodynamic and structural parameters have been comprehensively investigated by DFT to yield a justified conclusion.

Ten Chemical Innovations That Will Change Our World: IUPAC identifies emerging technologies in Chemistry with potential to make our planet more sustainable

Abstract 2019 is a very special year in chemistry. 2019 marks two major anniversaries: the 100th anniversary of the founding of the International Union of Pure and Applied Chemistry (IUPAC), and the 150th anniversary of Dimitri Mendeleev’s first publication on the Periodic Table of Elements [1]. IUPAC is the global organization that, among many other things, established a common language for chemistry—enabling scientific research, education, and trade. In a similar manner, Mendeleev’s system classified all the elements that were known at the time, and even predicted the existence of elements that would only come to be discovered years later. These two anniversaries are closely entwined, as IUPAC has played a major role developing of the modern Periodic Table by ensuring that the most authoritative version of the table is accessible to everyone [2], establishing names and symbols for the newly discovered elements, and also constantly reviewing its accuracy through the IUPAC Commission on Isotopic Abundances and Atomic Weights.

Mendelevium 101.

The first element to be identified one atom at a time was named after the main architect of the modern periodic table. This seemingly straightforward etymological choice illustrates how scientific recognition can eclipse geopolitical tensions, says Anne Pichon.

Causal explanation and the periodic table

The periodic table represents and organizes all known chemical elements on the basis of their properties. While the importance of this table in chemistry is uncontroversial, the role that it plays in scientific reasoning remains heavily disputed. Many philosophers deny the explanatory role of the table and insist that it is “merely” classificatory (Shapere, in F. Suppe (Ed.) The structure of scientific theories, University of Illinois Press, Illinois, 1977; Scerri in Erkenntnis 47:229–243, 1997). In particular, it has been claimed that the table does not figure in causal explanation because it “does not reveal causal structure” (Woody in Science after the practice turn in the philosophy, history, and social studies of science, Routledge Taylor & Francis Group, New York, 2014). This paper provides an analysis of what it means to say that a scientific figure reveals causal structure and it argues that the modern periodic table does just this. It also clarifies why these “merely” classificatory claims have seemed so compelling–this is because these claims often focus on the earliest periodic tables, which lack the causal structure present in modern versions.

The short form of Mendeleev’s Periodic Table of Chemical Elements: toolbox for learning the basics of inorganic chemistry. A contribution to celebrate 150 years of the Periodic Table in 2019

A condensed overview about the forefathers’ and Mendeleev’s contribution to the compilation of the Periodic Table of Chemical Elements is presented. Milestones en route to the modern Periodic Table are ‘electrification’ of the Periodic Law, discovery of the rare-earth elements and the noble gases, investigation of the atomic structure and discovery of the transuranic elements. Then the contribution focuses on the Table’s short form as toolbox for learning the basics of inorganic chemistry. Similarities and differences in the chemical behavior of elements on the basis of full, close and approximate electronic analogies and the kainosymmetric sublevels (1s, 2p, 3d, 4f) are described. A question/answer section completes the article.

An Effective Method of Introducing the Periodic Table as a Crossword Puzzle at the High School Level

A simple method to introduce the modern periodic table of elements at the high school level as a game of solving a crossword puzzle is presented here. A survey to test the effectiveness of this new method relative to the conventional method, involving use of a wall-mounted chart of the periodic table, was conducted on a convenience sample. This sample comprised over 200 school students learning introductory chemistry in India. The study sample of about 100 students was identified on the basis of a test. In the new method, a blank chart of the modern periodic table was used as an educational aid. Students entered symbols of elements in the blank chart in a manner very similar to solving a crossword puzzle by making use of clues provided to them. The scores of the tests conducted before and after the introduction to the periodic table to the treatment and control groups of the students, by the new and the conventional method, respectively, were analyzed. The comparison demonstrated the new method to be more effective than the conventional method in facilitating the students in constructing knowledge through hands-on learning regarding the structure and characteristics of the periodic table, namely, the periodicity and the predictability of elemental properties.

The Periodic Pyramid

The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy the shells identified by the principle quantum numbers n = 1, 2, 3, and 4, respectively. The numbers 2, 8, 18, and 32 are shown in this work to be related to the triangular numbers from mathematical number theory. The relationship to the triangular numbers, in turn, suggests an alternate method for arranging elements in terms of periodicity. The resulting three-dimensional “periodic pyramid” is highly symmetric in shape. Just as is true in the modern periodic table, each layer of the periodic pyramid can be separated into shell and subshell contributions. Examining the pyramid’s structure is arguably a pedagogically useful activity for college-level introductory or physical chemistry students, as it provides an opportunity to further ponder the shell model of the atom and the origins of periodicity. The connections to number theory are used to show that the outermost subshell of a given shell contains (2n – 1) orbitals.

Proposal of Actual Positions of Hydrogen (H) and Helium (He) in Modern Periodic Table

The actual positions of H and He in modern periodic table can be determined according to their dual characteristics (electro-positive and electro-negative) and final electronic configuration respectively. It is seen that a new group for H and two sub-groups of 0-group (zero group) for He in periodic table are needed in this respect.

A Postage Stamp About the Periodic Table

Presents a postage stamp issued in Spain in honor of Mendeleev and the modern periodic table that could serve as an opportunity to link chemistry and art.

Disease, Culture and History

It is an unremarkable truism that not so long ago most historians of medicine were white male doctors documenting the progress of medical ideas and practices. But now medical historians in Australia, the United States and Britain, if not elsewhere are more likely to have learned a wry scepticism in Ph.D. programs and to write a critical social or a cultural history of disease or health care. During the past twenty years or so the discipline expanded and became more diverse and, as it did so, the verbal qualifiers proliferated around our subject. What is it now that we do? Is it intellectual or social or cultural history of medicine, of biomedical science, of health, of illness, of suffering or of disease? And if this dispersal of interests had not already rendered our disciplinary identity sufficiently complex, it now seems that each element of this modern periodic table has an unstable valence. What is 'disease'? What counts as 'medicine? What is 'culture'? Even the

Evolution of the Modern Periodic Table

In this review, the evolution of the Modern Periodic Table is traced beginning with the original version of Dimitri Mendeleev in 1869. Emphasis is placed on the upper end with a description of the revision to accommodate the actinide series of elements at the time of World War II and the more recent research on the observed and predicted chemical properties of the transactinide elements (beyond atomic number 103). A Modern Periodic Table includes undiscovered elements up to atomic number 118 and a Futuristic Periodic Table with additional undiscovered elements up to atomic number 168 is included.

Periodic Classification of Elements

To the three requirements of a modern Periodic Table, as stated by A. A. Clifford1, must be added a fourth, namely, that it should be in as close accord as possible with chemical facts, and above all with the most fundamental of these, valency. It is only in Group IV that there is any strong chemical support for the sub-group arrangement. In other groups the only real justification is that the members of both sub-groups have the same maximum valency and some have the same characteristic valency. In Clifford's table even this slender justification is destroyed by the inclusion of Pr with Pa, Nd with U, Sm with Pu and Eu with Am, not merely in the same group but also in the same sub-group c. Advocates of ‘long’ forms of table are unlikely to be converted in this way.