The Periodic System of Chemical Elements: Old and New Developments
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Evolution and Understanding of the D-Block Elements in the Periodic Table Cite This: Dalton Trans., 2019, 48, 9408 Edwin C
Dalton Transactions View Article Online PERSPECTIVE View Journal | View Issue Evolution and understanding of the d-block elements in the periodic table Cite this: Dalton Trans., 2019, 48, 9408 Edwin C. Constable Received 20th February 2019, The d-block elements have played an essential role in the development of our present understanding of Accepted 6th March 2019 chemistry and in the evolution of the periodic table. On the occasion of the sesquicentenniel of the dis- DOI: 10.1039/c9dt00765b covery of the periodic table by Mendeleev, it is appropriate to look at how these metals have influenced rsc.li/dalton our understanding of periodicity and the relationships between elements. Introduction and periodic tables concerning objects as diverse as fruit, veg- etables, beer, cartoon characters, and superheroes abound in In the year 2019 we celebrate the sesquicentennial of the publi- our connected world.7 Creative Commons Attribution-NonCommercial 3.0 Unported Licence. cation of the first modern form of the periodic table by In the commonly encountered medium or long forms of Mendeleev (alternatively transliterated as Mendelejew, the periodic table, the central portion is occupied by the Mendelejeff, Mendeléeff, and Mendeléyev from the Cyrillic d-block elements, commonly known as the transition elements ).1 The periodic table lies at the core of our under- or transition metals. These elements have played a critical rôle standing of the properties of, and the relationships between, in our understanding of modern chemistry and have proved to the 118 elements currently known (Fig. 1).2 A chemist can look be the touchstones for many theories of valence and bonding. -
The Periodic Electronegativity Table
The Periodic Electronegativity Table Jan C. A. Boeyens Unit for Advanced Study, University of Pretoria, South Africa Reprint requests to J. C. A. Boeyens. E-mail: [email protected] Z. Naturforsch. 2008, 63b, 199 – 209; received October 16, 2007 The origins and development of the electronegativity concept as an empirical construct are briefly examined, emphasizing the confusion that exists over the appropriate units in which to express this quantity. It is shown how to relate the most reliable of the empirical scales to the theoretical definition of electronegativity in terms of the quantum potential and ionization radius of the atomic valence state. The theory reflects not only the periodicity of the empirical scales, but also accounts for the related thermochemical data and serves as a basis for the calculation of interatomic interaction within molecules. The intuitive theory that relates electronegativity to the average of ionization energy and electron affinity is elucidated for the first time and used to estimate the electron affinities of those elements for which no experimental measurement is possible. Key words: Valence State, Quantum Potential, Ionization Radius Introduction electronegative elements used to be distinguished tra- ditionally [1]. Electronegativity, apart from being the most useful This theoretical notion, in one form or the other, has theoretical concept that guides the practising chemist, survived into the present, where, as will be shown, it is also the most bothersome to quantify from first prin- provides a precise definition of electronegativity. Elec- ciples. In historical context the concept developed in a tronegativity scales that fail to reflect the periodicity of natural way from the early distinction between antag- the L-M curve will be considered inappropriate. -
An Alternate Graphical Representation of Periodic Table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt
An Alternate Graphical Representation of Periodic table of Chemical Elements Mohd Abubakr1, Microsoft India (R&D) Pvt. Ltd, Hyderabad, India. [email protected] Abstract Periodic table of chemical elements symbolizes an elegant graphical representation of symmetry at atomic level and provides an overview on arrangement of electrons. It started merely as tabular representation of chemical elements, later got strengthened with quantum mechanical description of atomic structure and recent studies have revealed that periodic table can be formulated using SO(4,2) SU(2) group. IUPAC, the governing body in Chemistry, doesn‟t approve any periodic table as a standard periodic table. The only specific recommendation provided by IUPAC is that the periodic table should follow the 1 to 18 group numbering. In this technical paper, we describe a new graphical representation of periodic table, referred as „Circular form of Periodic table‟. The advantages of circular form of periodic table over other representations are discussed along with a brief discussion on history of periodic tables. 1. Introduction The profoundness of inherent symmetry in nature can be seen at different depths of atomic scales. Periodic table symbolizes one such elegant symmetry existing within the atomic structure of chemical elements. This so called „symmetry‟ within the atomic structures has been widely studied from different prospects and over the last hundreds years more than 700 different graphical representations of Periodic tables have emerged [1]. Each graphical representation of chemical elements attempted to portray certain symmetries in form of columns, rows, spirals, dimensions etc. Out of all the graphical representations, the rectangular form of periodic table (also referred as Long form of periodic table or Modern periodic table) has gained wide acceptance. -
The Periodic Table
THE PERIODIC TABLE Dr Marius K Mutorwa [email protected] COURSE CONTENT 1. History of the atom 2. Sub-atomic Particles protons, electrons and neutrons 3. Atomic number and Mass number 4. Isotopes and Ions 5. Periodic Table Groups and Periods 6. Properties of metals and non-metals 7. Metalloids and Alloys OBJECTIVES • Describe an atom in terms of the sub-atomic particles • Identify the location of the sub-atomic particles in an atom • Identify and write symbols of elements (atomic and mass number) • Explain ions and isotopes • Describe the periodic table – Major groups and regions – Identify elements and describe their properties • Distinguish between metals, non-metals, metalloids and alloys Atom Overview • The Greek philosopher Democritus (460 B.C. – 370 B.C.) was among the first to suggest the existence of atoms (from the Greek word “atomos”) – He believed that atoms were indivisible and indestructible – His ideas did agree with later scientific theory, but did not explain chemical behavior, and was not based on the scientific method – but just philosophy John Dalton(1766-1844) In 1803, he proposed : 1. All matter is composed of atoms. 2. Atoms cannot be created or destroyed. 3. All the atoms of an element are identical. 4. The atoms of different elements are different. 5. When chemical reactions take place, atoms of different elements join together to form compounds. J.J.Thomson (1856-1940) 1. Proposed the first model of the atom. 2. 1897- Thomson discovered the electron (negatively- charged) – cathode rays 3. Thomson suggested that an atom is a positively- charged sphere with electrons embedded in it. -
The Development of the Periodic Table and Its Consequences Citation: J
Firenze University Press www.fupress.com/substantia The Development of the Periodic Table and its Consequences Citation: J. Emsley (2019) The Devel- opment of the Periodic Table and its Consequences. Substantia 3(2) Suppl. 5: 15-27. doi: 10.13128/Substantia-297 John Emsley Copyright: © 2019 J. Emsley. This is Alameda Lodge, 23a Alameda Road, Ampthill, MK45 2LA, UK an open access, peer-reviewed article E-mail: [email protected] published by Firenze University Press (http://www.fupress.com/substantia) and distributed under the terms of the Abstract. Chemistry is fortunate among the sciences in having an icon that is instant- Creative Commons Attribution License, ly recognisable around the world: the periodic table. The United Nations has deemed which permits unrestricted use, distri- 2019 to be the International Year of the Periodic Table, in commemoration of the 150th bution, and reproduction in any medi- anniversary of the first paper in which it appeared. That had been written by a Russian um, provided the original author and chemist, Dmitri Mendeleev, and was published in May 1869. Since then, there have source are credited. been many versions of the table, but one format has come to be the most widely used Data Availability Statement: All rel- and is to be seen everywhere. The route to this preferred form of the table makes an evant data are within the paper and its interesting story. Supporting Information files. Keywords. Periodic table, Mendeleev, Newlands, Deming, Seaborg. Competing Interests: The Author(s) declare(s) no conflict of interest. INTRODUCTION There are hundreds of periodic tables but the one that is widely repro- duced has the approval of the International Union of Pure and Applied Chemistry (IUPAC) and is shown in Fig.1. -
Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel
THESIS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel EMMA H. K. ANEHEIM Department of Chemical and Biological Engineering CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden, 2012 Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel EMMA H. K. ANEHEIM ISBN 978-91-7385-751-2 © EMMA H. K. ANEHEIM, 2012. Doktorsavhandlingar vid Chalmers tekniska högskola Ny serie Nr 3432 ISSN 0346-718X Department of Chemical and Biological Engineering Chalmers University of Technology SE-412 96 Gothenburg Sweden Telephone + 46 (0)31-772 1000 Cover: Radiotoxicity as a function of time for the once through fuel cycle (left) compared to one P&T cycle using the GANEX process (right) (efficiencies: partitioning from Table 5.5.4, transmutation: 99.9%). Calculations performed using RadTox [HOL12]. Chalmers Reproservice Gothenburg, Sweden 2012 Development of a Solvent Extraction Process for Group Actinide Recovery from Used Nuclear Fuel EMMA H. K. ANEHEIM Department of Chemical and Biological Engineering Chalmers University of Technology Abstract When uranium is used as fuel in nuclear reactors it both undergoes neutron induced fission as well as neutron capture. Through successive neutron capture and beta decay transuranic elements such as neptunium, plutonium, americium and curium are produced in substantial amounts. These radioactive elements are mostly long-lived and contribute to a large portion of the long term radiotoxicity of the used nuclear fuel. This radiotoxicity is what makes it necessary to isolate the used fuel for more than 100,000 years in a final repository in order to avoid harm to the biosphere. -
The Group 1A and Group 2A Elements
Cotton chapter 10,11 Group 1A Group 1A Qualitative alkali metal analysis Alkali Metals y The group 1A elements with their ns1 valence electron configurations are very active metals. They lose their valence electrons very readily. They have low ionization energies and react with nonmetals to form ionic solids. 2Na(s) +Cl2(g) Æ 2NaCl(s) y The expected trend in reducing ability, Cs>Rb>K>Na>Li y Alkali metals all react vigorously with water to release hydrogen gas. + ‐ 2M(s) +2H2O(l) Æ 2M (aq) +2OH(aq) +H2(g) y Observed reducing abilities: Li>K>Na First ionization energy Soda production Properties and Trends in Group 1A y The Group 1A metals exhibit regular trends for a number of properties. y Irregular trends suggest that factors are working against each other in determining a property (such as the density “discrepancy” between sodium and potassium). y The alkali metals have two notable physical properties: they are all soft and have low melting points. y When freshly cut, the alkali metals are bright and shiny—typical metallic properties. The metals quickly tarnish, however, as they react with oxygen in the air. Alkali Metal Oxides In the presence of ample oxygen, 4Li + O2 → 2Li2O(regularoxide) 2Na + O2 → Na2O2 (peroxide) K+O2 → KO2 (superoxide) Rb + O2 → RbO2 (superoxide) Cs + O2 → CsO2 (superoxide) The oxides of Group 1A Direct reaction of the alkali metals with O2 gives : Li ‐> oxide, peroxide (trace) Na ‐> peroxide , oxide (trace) K,Rb,Cs ‐> superoxide Diagonal Relationships: The Special Case of Lithium In some of its properties, lithium and its compounds resemble magnesium and its compounds. -
TEK 8.5C: Periodic Table
Name: Teacher: Pd. Date: TEK 8.5C: Periodic Table TEK 8.5C: Interpret the arrangement of the Periodic Table, including groups and periods, to explain how properties are used to classify elements. Elements and the Periodic Table An element is a substance that cannot be separated into simpler substances by physical or chemical means. An element is already in its simplest form. The smallest piece of an element that still has the properties of that element is called an atom. An element is a pure substance, containing only one kind of atom. The Periodic Table of Elements is a list of all the elements that have been discovered and named, with each element listed in its own element square. Elements are represented on the Periodic Table by a one or two letter symbol, and its name, atomic number and atomic mass. The Periodic Table & Atomic Structure The elements are listed on the Periodic Table in atomic number order, starting at the upper left corner and then moving from the left to right and top to bottom, just as the words of a paragraph are read. The element’s atomic number is based on the number of protons in each atom of that element. In electrically neutral atoms, the atomic number also represents the number of electrons in each atom of that element. For example, the atomic number for neon (Ne) is 10, which means that each atom of neon has 10 protons and 10 electrons. Magnesium (Mg) has an atomic number of 12, which means it has 12 protons and 12 electrons. -
Chapter 10 – Chemical Reactions Notes
Chapter 8 – Chemical Reactions Notes Chemical Reactions: Chemical reactions are processes in which the atoms of one or more substances are rearranged to form different chemical compounds. How to tell if a chemical reaction has occurred (recap): Temperature changes that can’t be accounted for. o Exothermic reactions give off energy (as in fire). o Endothermic reactions absorb energy (as in a cold pack). Spontaneous color change. o This happens when things rust, when they rot, and when they burn. Appearance of a solid when two liquids are mixed. o This solid is called a precipitate. Formation of a gas / bubbling, as when vinegar and baking soda are mixed. Overall, the most important thing to remember is that a chemical reaction produces a whole new chemical compound. Just changing the way that something looks (breaking, melting, dissolving, etc) isn’t enough to qualify something as a chemical reaction! Balancing Equations Notes: Things to keep in mind when looking at the recipes for chemical reactions: 1) The stuff before the arrow is referred to as the “reactants” or “reagents”, and the stuff after the arrow is called the “products.” 2) The number of atoms of each element is the same on both sides of the arrow. Even though there may be different numbers of molecules, the number of atoms of each element needs to remain the same to obey the law of conservation of mass. 3) The numbers in front of the formulas tell you how many molecules or moles of each chemical are involved in the reaction. 4) Equations are nothing more than chemical recipes. -
Where Is Water on the Periodic Table
Where Is Water On The Periodic Table Grum Jess regrown some tirls and risk his creepies so ambrosially! Roderigo is edaphic: she libel ahold and budges her barm. Corrugate and percipient Ford never digitized lickerishly when Janos literalising his ultrafilter. Unsubscribe from rivers from three particles in marah was it is where water on the periodic table The periodic tables is where compounds is a question yourself. Periodic table organized his element does not the water where is on oxygen and silicon does the universe and the sight of concentration and. In the marine environment. The table is where it is generally halogens are. An appreciation of water resources, data for gym, make tungsten gets very sophisticated pieces of oxo anions. Tcp connection time is table is on the water periodic. In the 9th century BC a Spartan lawgiver invented a drinking cup that could go mud stick missing its turn Later on the posture of medicine Hippocrates developed a device called the Hippocrates Sleeve a cloth bag weight was used to strain boiled rain water eliminating hoarseness and even smell. His law that is an apartment building large version of a ratio of where water was given element in open a pond would accumulate at an outer shells need. On their properties? Free 2-day shipping Buy Chemistry Elements Pet Mat the Food make Water Periodic Table of Elements in Green Shades Education Themed Non-Slip Rubber. The wall of the cell is the plasma membrane that controls the rate and type of ions and molecules passing into and out of the cell. -
Chemistry - B.S
Chemistry - B.S. College of (Biochemistry Option) Arts and Sciences The Department of Chemistry offers the Bachelor of Science degree for students who Graduation Composition and Communication Requirement intend to become professional chemists or do graduate work in chemistry or a closely (GCCR) related discipline. There are three options in the B.S. program: a traditional track WRD 310 Writing in the Natural Sciences ............................................................. 3 covering all the major areas of chemistry, an option that emphasizes biochemistry and an option in materials chemistry. The Biochemistry and Traditional Options are Graduation Composition and Communication certified by the American Chemical Society. A Bachelor of Arts degree program is Requirement hours (GCCR) .................................................................... 3 offered as well for students who want greater flexibility in the selection of courses to perhaps pursue more diverse degree options, including dual and double majors. For College Requirements all majors CHE 109 and CHE 110 have been defined as equivalent to CHE 105. The I. Foreign Language (placement exam recommended) ................................... 0-14 Department also offers the Master of Science and the Doctor of Philosophy degree. II. Disciplinary Requirements a. Natural Science (completed by Major Requirements) 128 hours b. Social Science ......................................................................................... 3 Any student earning a Bachelor of Science (BS) -
Of the Periodic Table
of the Periodic Table teacher notes Give your students a visual introduction to the families of the periodic table! This product includes eight mini- posters, one for each of the element families on the main group of the periodic table: Alkali Metals, Alkaline Earth Metals, Boron/Aluminum Group (Icosagens), Carbon Group (Crystallogens), Nitrogen Group (Pnictogens), Oxygen Group (Chalcogens), Halogens, and Noble Gases. The mini-posters give overview information about the family as well as a visual of where on the periodic table the family is located and a diagram of an atom of that family highlighting the number of valence electrons. Also included is the student packet, which is broken into the eight families and asks for specific information that students will find on the mini-posters. The students are also directed to color each family with a specific color on the blank graphic organizer at the end of their packet and they go to the fantastic interactive table at www.periodictable.com to learn even more about the elements in each family. Furthermore, there is a section for students to conduct their own research on the element of hydrogen, which does not belong to a family. When I use this activity, I print two of each mini-poster in color (pages 8 through 15 of this file), laminate them, and lay them on a big table. I have students work in partners to read about each family, one at a time, and complete that section of the student packet (pages 16 through 21 of this file). When they finish, they bring the mini-poster back to the table for another group to use.