who made up the periodic table of elements
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William Odling, FRS (5 September 1829 in Southwark, London – 17 February 1921 in Oxford) was an English chemist who contributed to the development of the periodic table. In the 1860s Odling, like many chemists, was working towards classifying the elements, an effort that would eventually lead to the periodic table of elements. He was intrigued by atomic weights and the periodic occurrence of chemical properties. William Odling and Lothar Meyer drew up tables similar, but with improvements on, Dmitri Mendeleev's original table. Odling drew up a table of elements using repeating units of seven elements, which bears a striking resemblance to Mendeleev's first table. The groups are horizontal, the elements are in order of increasing atomic weight and there are vacant slots for undiscovered ones. In addition, Odling overcame the tellurium-iodine problem and he even managed to get thallium, lead, mercury and platinum in the right groups - something that Mendeleev failed to do at his first attempt. Odling failed to achieve recognition, however, since it is suspected that he, as Secretary of the Chemical Society of London, was instrumental in discrediting John Alexander Reina Newlands' efforts at getting his own periodic table published. One such unrecognised aspect was for the suggestion he, Odling, made in a lecture he gave at the Royal Institution in 1855 entitled The Constitution of Hydrocarbons in which he proposed a methane type for carbon (Proceedings of the Royal Institution, 1855, vol 2, p. 63-66). August Kekulé made a similar suggestion in 1857, then in a subsequent paper later that same year proposed that carbon is a tetravalent element. Career Odling became a Chemistry Lecturer at St Bartholomew's Hospital Medical School and a Demonstrator at Guy's Hospital Medical School in 1850. Leaving St Bartholomew's in 1868 he became a Fullerian Professor of Chemistry at the Royal Institution where in 1868 and 1870 he was invited to deliver the Royal Institution Christmas Lecture on The Chemical Changes of Carbon and Burning and Unburning respectively. In 1872 he left the Royal Institution and became Waynflete Professor of Chemistry and a fellow of Worcester College, Oxford, where he stayed still his retirement in 1912. Odling also served as a fellow (1848–1856), Honorary Secretary (1856–1869), Vice-President (1869–1872) and President (1873–1875) of the Chemical Society of London as well as a Censor (1878–1880 and 1882–1891), Vice-President (1878–1880 and 1888–1891) and President (1883–1888) of the Institute of Chemistry. In 1859 he was made a fellow of the Royal Society of London and in 1875 he was granted an honorary PhD by Leiden University, the Netherlands. See also History of the periodic table References Fullerian Professorships 1829 births 1921 deaths People from Southwark 19th-century British chemists Fellows of the Royal Society Academics of the Medical College of St Bartholomew's Hospital Fellows of Worcester College, Oxford Waynflete Professors of Chemistry People involved with the periodic table 20th-century British chemists
William Odling
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The periodic table is an arrangement of the chemical elements, structured by their atomic number, electron configuration and recurring chemical properties. In the basic form, elements are presented in order of increasing atomic number, in the reading sequence. Then, rows and columns are created by starting new rows and inserting blank cells, so that rows (periods) and columns (groups) show elements with recurring properties (called periodicity). For example, all elements in group (column) 18 are noble gases that are largely—though not completely—unreactive. The history of the periodic table reflects over two centuries of growth in the understanding of the chemical and physical properties of the elements, with major contributions made by Antoine-Laurent de Lavoisier, Johann Wolfgang Döbereiner, John Newlands, Julius Lothar Meyer, Dmitri Mendeleev, Glenn T. Seaborg, and others. Early history Nine chemical elements – carbon, sulfur, iron, copper, silver, tin, gold, mercury, and lead, have been known since before antiquity, as they are found in their native form and are relatively simple to mine with primitive tools. Around 330 BCE, the Greek philosopher Aristotle proposed that everything is made up of a mixture of one or more roots, an idea originally suggested by the Sicilian philosopher Empedocles. The four roots, which the Athenian philosopher Plato called elements, were earth, water, air and fire. Similar ideas about these four elements existed in other ancient traditions, such as Indian philosophy. A few extra elements were known in the age of alchemy: zinc, arsenic, antimony, and bismuth. Platinum was also known to pre-Columbian South Americans, but knowledge of it did not reach Europe until the 16th century. First categorizations The history of the periodic table is also a history of the discovery of the chemical elements. The first person in recorded history to discover a new element was Hennig Brand, a bankrupt German merchant. Brand tried to discover the philosopher's stone—a mythical object that was supposed to turn inexpensive base metals into gold. In 1669, or later, his experiments with distilled human urine resulted in the production of a glowing white substance, which he called "cold fire" (kaltes Feuer). He kept his discovery secret until 1680, when Anglo-Irish chemist Robert Boyle rediscovered phosphorus and published his findings. The discovery of phosphorus helped to raise the question of what it meant for a substance (any given variety of matter) to be an element, in a world where versions of atomic theory were only speculative and later understandings of the nature of substances were only beginning to become possible. In 1661, Boyle defined elements as "those primitive and simple Bodies of which the mixt ones are said to be composed, and into which they are ultimately resolved." In 1718, Étienne François Geoffroy's Affinity Table made use of several aspects — (1) tabular grouping and (2) correlation with chemical affinity — that would later be reprised. In 1789, French chemist Antoine Lavoisier wrote Traité Élémentaire de Chimie (Elementary Treatise of Chemistry), which is considered to be the first modern textbook about chemistry. Lavoisier defined an
History of the periodic table
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Edward G. Mazurs (1894–1983) was a chemist who wrote a history of the periodic system of the chemical elements which is still considered a "classic book on the history of the periodic table". Originally self-published as Types of graphic representation of the periodic system of chemical elements (1957), it was reviewed by the ACS in 1958 as "the most complete survey of the range of human imagination in representing graphically the Mendeleev periodic law." A revised "centenary" edition covering a full 100 years of periodic tables was republished under the title Graphic Representations of the Periodic System During One Hundred Years in 1974. Mazurs provided a comprehensive analysis and classification of periodic tables, listing and classifying over 700 periodic tables. He recommended Charles Janet's left-step system and suggested that it could be expanded into three dimensions. Life and career Mazurs was born in Latvia, then under Czarist rule. He earned a master's degree at the University of Riga (later the University of Latvia), teaching there after independence as a professor of chemistry, from 1919 to 1940. Mazurs fled with his wife and son when Latvia was reoccupied by the Soviet Union in 1944 and spent years as a refugee, some of it in a refugee camp in Regensberg, Germany. He immigrated to America in 1949. After working at Argo Corn Products, he eventually obtained a professorship at Westmont College in Santa Barbara, California. Publications In a self-published book, Types of Graphic Representation of the Periodic System of the Elements (1957) he listed some 700 images published since 1862, classified under 146 heads. He brought out a greatly expanded version in 1974: Graphic Representations of the Periodic System during One Hundred Years. Mazurs's books are difficult to use because the references are divided into 146 corresponding sections, and the index refers to the types and not to pages. Nevertheless, his references are the most comprehensive and accurate ever compiled for the period covered. He cited authors writing in at least 24 languages and from fifty countries. Working before the age of the photocopier, he copied his illustrations by hand and generally brought them up to date by adding elements missing from the original works, and sometimes he changed them radically. He gave 67 references to the modern standard medium long table, but paid it little attention, attributing its origin to Dmitri Mendeleev, who gave only a fragmentary description of it because he disliked interrupted series. Mazurs preferred tables based on electronic structure, notably that of Charles Janet and his own modification of it. Papers His notes and papers are held in the library of the Science History Institute, 315 Chestnut Street, Philadelphia, Pennsylvania 19106, where they occupy 4 linear feet, and include lantern slides and transparencies of periodic tables which appear in his books. Periodic tables External links Edward G. Mazurs Collection of Periodic Systems Images. Science History Institute Digital Collections. (87 high-resolution scans of models of the periodic table used by Edward G. Mazurs in Types of Graphic Representation of
Edward G. Mazurs
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In nuclear chemistry, the actinide concept (also known as actinide hypothesis) proposed that the actinides form a second inner transition series homologous to the lanthanides. Its origins stem from observation of lanthanide-like properties in transuranic elements in contrast to the distinct complex chemistry of previously known actinides. Glenn Theodore Seaborg, one of the researchers who synthesized transuranic elements, proposed the actinide concept in 1944 as an explanation for observed deviations and a hypothesis to guide future experiments. It was accepted shortly thereafter, resulting in the placement of a new actinide series comprising elements 89 (actinium) to 103 (lawrencium) below the lanthanides in Dmitri Mendeleev's periodic table of the elements. Origin In the late 1930s, the first four actinides (actinium, thorium, protactinium, and uranium) were known. They were believed to form a fourth series of transition metals, characterized by the filling of 6d orbitals, in which thorium, protactinium, and uranium were respective homologs of hafnium, tantalum, and tungsten. This view was widely accepted as chemical investigations of these elements revealed various high oxidation states and characteristics that closely resembled the 5d transition metals. Nevertheless, research into quantum theory by Niels Bohr and subsequent publications proposed that these elements should constitute a 5f series analogous to the lanthanides, with calculations that the first 5f electron should appear in the range from atomic number 90 (thorium) to 99 (einsteinium). Inconsistencies between theoretical models and known chemical properties thus made it difficult to place these elements in the periodic table. The first appearance of the actinide concept may have been in a 32-column periodic table constructed by Alfred Werner in 1905. Upon determining the arrangement of the lanthanides in the periodic table, he placed thorium as a heavier homolog of cerium, and left spaces for hypothetical radioelements in the seventh period, though he did not establish the correct order of the known actinides. Following the discoveries of transuranic elements neptunium and plutonium in 1940 and preliminary investigations of their chemistry, their placement as a fourth transition metal series was challenged. These new elements exhibited various properties that suggested a close chemical similarity to uranium rather than their supposed transition metal homologs. Subsequent experiments targeting the then-unknown elements americium and curium raised further questions. Seaborg et al. failed to identify these elements under the premise that they were transition metals, but they were successfully separated and discovered in 1944, following the assumption that they would be chemically similar to the lanthanides. Further experiments corroborated the hypothesis of an actinide (then referred to as "thorides" or "uranides") series. A spectroscopic study at the Los Alamos National Laboratory by McMillan, Wahl, and Zachariasen indicated that 5f orbitals, rather than 6d orbitals, were being filled. However, these studies could not unambiguously determine the first element with 5f electrons and therefore the first element in the actinide series. Acceptance The discoveries of americium and curium under the hypothesis that they resembled the lanthanides prompted Seaborg to propose the concept of an actinide series to his colleagues in 1944 –
Actinide concept
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A chemical element is a chemical substance that cannot be broken down into other substances by chemical reactions. The basic particle that constitutes a chemical element is the atom. Chemical elements are identified by the number of protons in the nuclei of their atoms, known as the element's atomic number. For example, oxygen has an atomic number of 8, meaning that each oxygen atom has 8 protons in its nucleus. Two or more atoms of the same element can combine to form molecules, in contrast to chemical compounds or mixtures, which contain atoms of different elements. Atoms can be transformed into different elements in nuclear reactions, which change an atom's atomic number. Almost all of the baryonic matter of the universe is composed of chemical elements (among rare exceptions are neutron stars). When different elements undergo chemical reactions, atoms are rearranged into new compounds held together by chemical bonds. Only a few elements, such as silver and gold, are found uncombined as relatively pure native element minerals. Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. Air is primarily a mixture of molecular nitrogen and oxygen, though it does contain compounds including carbon dioxide and water, as well as atomic argon, a noble gas which is chemically inert and therefore does not undergo chemical reactions. The history of the discovery and use of the elements began with primitive human societies that discovered native minerals like carbon, sulfur, copper and gold (though the concept of a chemical element was not yet understood). Attempts to classify materials such as these resulted in the concepts of classical elements, alchemy, and various similar theories throughout human history. Much of the modern understanding of elements developed from the work of Dmitri Mendeleev, a Russian chemist who published the first recognizable periodic table in 1869. This table organizes the elements by increasing atomic number into rows ("periods") in which the columns ("groups") share recurring ("periodic") physical and chemical properties. The periodic table summarizes various properties of the elements, allowing chemists to derive relationships between them and to make predictions about compounds and potential new ones. By November 2016, the International Union of Pure and Applied Chemistry had recognized a total of 118 elements. The first 94 occur naturally on Earth, and the remaining 24 are synthetic elements produced in nuclear reactions. Save for unstable radioactive elements (radionuclides) which decay quickly, nearly all of the elements are available industrially in varying amounts. The discovery and synthesis of further new elements is an ongoing area of scientific study. Description The lightest chemical elements are hydrogen and helium, both created by Big Bang nucleosynthesis during the first 20 minutes of the universe in a ratio of around 3:1 by mass (or 12:1 by number of atoms), along with tiny traces of the next two elements, lithium and beryllium. Almost all other elements found in nature were made by various natural methods of nucleosynthesis. On Earth, small amounts of new atoms are naturally produced in
Chemical element
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Gustavus Detlef Hinrichs (2 December 1836 – 14 February 1923) was a chemist and natural philosopher most widely known for his findings on periodic laws within the chemical elements. Life Hinrichs was born in 1836 in Lunden in the Duchy of Holstein, which at that time was under the rule of Denmark although it was simultaneously part of the German Confederation. He attended the local polytechnic school and the University of Copenhagen. During his schooling he published several articles and books, including descriptions of the magnetic field of Earth and its interaction with the aether. Hinrichs graduated in 1860, between the First and Second Schleswig Wars. He emigrated later that year to the United States, settling initially in Davenport, Iowa, where he taught school, then in nearby Iowa City. In 1863 he was appointed a professor of natural philosophy, chemistry, and modern languages at the University of Iowa. He founded the first state weather and crop service in the United States and headed the Iowa Weather Service until 1886. He was first to identify and name the straight-line storm phenomenon he called the "derecho." He stayed at the University of Iowa until 1886, when he was fired by the state Board of Regents due to disputes with the university president and faculty colleagues. He became a professor at the St. Louis University in 1889 and taught there until his retirement in 1907. Periodic law Hinrichs is one of the discoverers of the periodic laws, which are the basis for the periodic table of elements. Although his contribution is not generally considered as important as those of Dmitri Mendeleev or Lothar Meyer, in 1867 (two years before Mendeleev) he presented his ideas on periodicity among the chemical elements in his privately printed book Programme der Atommechanik, and in slightly revised form in 1869. His first periodic table had the form of a double spiral, and the elements were placed into the structure according to their atomic mass. Hinrichs also postulated a theory on the cause of the periodicity within the chemical elements based on his theory of the composition of elements out of smaller Panatome. The Trigonoides were the nonmetals made from regular triangles, while the metallic Tetragonoides were made from squares. Algebraic formulas of how to mix squares and triangles yielded the periodic laws. His "controversial ideas and colorful personality" proved to be an obstacle to the acceptance of his theories. References 19th-century German chemists Emigrants from the Duchy of Holstein University of Iowa faculty Saint Louis University faculty 1836 births 1923 deaths University of Copenhagen alumni People involved with the periodic table Immigrants to the United States
Gustavus Detlef Hinrichs
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John Alexander Reina Newlands (26 November 1837 – 29 July 1898) was a British chemist who worked concerning the periodicity of elements. Biography Newlands was born in London in England, at West Square in Southwark, the son of a Scottish Presbyterian minister and his Italian wife. Newlands was home-schooled by his father, and later studied at the Royal College of Chemistry, now part of Imperial College London. He was interested in social reform and during 1860 served as a volunteer with Giuseppe Garibaldi in his military campaign to unify Italy. Returning to London, Newlands established himself as an analytical chemist in 1864. In 1868 he became chief chemist of James Duncan's London sugar refinery, where he introduced a number of improvements in processing. Later he quit the refinery and again became an analyst with his brother, Benjamin. Newlands was the first person to devise a periodic table of chemical elements arranged in order of their relative atomic masses published in Chemical News in February 1863. Continuing Johann Wolfgang Döbereiner's work with triads and Jean-Baptiste Dumas' families of similar elements, he published in 1865 his "Law of Octaves", which stated that "any given element will exhibit analogous behaviour to the eighth element following it in the table." Newlands arranged all of the known elements, starting with hydrogen and ending with thorium (atomic weight 232), into eight groups of seven, which he likened to octaves of music. In Newlands' table, the elements were ordered by the atomic weights that were known at the time and were numbered sequentially to show their order. Groups were shown going across the table, with periods going down – the opposite from the modern form of the periodic table. The incompleteness of the table alluded to the possible existence of additional, undiscovered elements. However, the Law of Octaves was ridiculed by some of Newlands' contemporaries, and the Society of Chemists did not accept his work for publication. After Dmitri Mendeleev and Lothar Meyer received the Davy Medal from the Royal Society for their later 'discovery' of the periodic table in 1882, Newlands fought for recognition of his earlier work and eventually received the Davy Medal in 1887. John Newlands died due to complications of surgery at his home in Lower Clapton, Middlesex and was buried at West Norwood Cemetery. His businesses was continued after his death by his younger brother, Benjamin. Works See also History of the periodic table References Further reading External links Cartage biography Newlands on classification of elements 1837 births 1898 deaths People from Southwark English chemists Analytical chemists Burials at West Norwood Cemetery People involved with the periodic table English people of Scottish descent English people of Italian descent
John Newlands (chemist)
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Clemens Alexander Winkler (December 26, 1838 – October 8, 1904) was a German chemist who discovered the element germanium in 1886, solidifying Dmitri Mendeleev's theory of periodicity. Life Winkler was born in 1838 in Freiberg, Kingdom of Saxony the son of a chemist who had studied under Berzelius. Winkler's early education was at schools in Freiberg, Dresden, and Chemnitz. In 1857 he entered the Freiberg University of Mining and Technology, where his knowledge of analytical chemistry surpassed what he was being taught there. Sixteen years later, Winkler was appointed a professor of chemical technology and analytical chemistry at the university. Winkler was elected a member of the Royal Swedish Academy of Sciences in 1892. In 1893, Winkler moved to Hamburg where he married his childhood sweetheart Tanja Braun. In 1902, Winkler resigned his professorship. He died in Dresden two years later of carcinoma at the age of 65. According to Brunck, Winkler wrote poetry, and according to McCay, Winkler's talents extended to playing several musical instruments. Discovery of germanium In 1886, Winkler was provided with a new mineral from the Himmelsfürst mine near Freiberg. The mineral, called argyrodite, was found by chemists to contain silver and sulfur. When Winkler subsequently analyzed the mineral, he found that the individual components only added up to about 93–94% of its total mass, leading him to suspect that a new and previously unknown element must be present. After additional chemical purification steps over several months, Winkler isolated the pure element, germanium, on February 6, 1886 and published his results. The mineral argyrodite that was Winkler's start toward finding germanium is now known to be a double sulfide with formula GeS2 · 4Ag2S. To place germanium into the periodic table, Mendeleev suggested that it might be ekacadmium, an element he had predicted earlier. In contrast, Lothar Meyer favored an identification of germanium with ekasilicon, a different predicted element. Winkler isolated more of the pure material, and eventually obtained enough to measure some of its physical and chemical properties. His results showed unequivocally that Meyer's interpretation was the correct one and that nearly all of the new element's properties matched Mendeleev predictions. The close match between what had been predicted for ekasilicon and what was found for germanium was clear evidence for the utility and power of the periodic table and the concept of periodicity. Other work In addition to his isolation and study of germanium, Winkler investigated the analysis of gases. He published a book on the subject, Handbook of Technical Gas Analysis, in 1884. In that book Winkler describes his invention of the three-way stopcock. He predicted the existence of silicon monoxide, SiO, and was the first to attempt to produce it by heating silica with silicon in 1890. However, he was unsuccessful because he was not able to heat the mixture to a high enough temperature using a combustion furnace. As no reaction occurred for him, Winkler incorrectly concluded that SiO does not exist, even though it was reported to have formed from
Clemens Winkler
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Dmitri Mendeleev published a periodic table of the chemical elements in 1869 based on properties that appeared with some regularity as he laid out the elements from lightest to heaviest. When Mendeleev proposed his periodic table, he noted gaps in the table and predicted that then-unknown elements existed with properties appropriate to fill those gaps. He named them eka-boron, eka-aluminium, eka-silicon, and eka-manganese, with respective atomic masses of 44, 68, 72, and 100. Prefixes To give provisional names to his predicted elements, Dmitri Mendeleev used the prefixes eka- , dvi- or dwi-, and tri-, from the Sanskrit names of digits 1, 2, and 3, depending upon whether the predicted element was one, two, or three places down from the known element of the same group in his table. For example, germanium was called eka-silicon until its discovery in 1886, and rhenium was called dvi-manganese before its discovery in 1926. The eka- prefix was used by other theorists, and not only in Mendeleev's own predictions. Before the discovery, francium was referred to as eka-caesium, and astatine as eka-iodine. Sometimes, eka- is still used to refer to some of the transuranic elements, for example, eka-radium for unbinilium. But current official IUPAC practice is to use a systematic element name based on the atomic number of the element as the provisional name, instead of being based on its position in the periodic table as these prefixes require. Original predictions The four predicted elements lighter than the rare-earth elements, eka-boron (Eb, under boron, B, 5), eka-aluminium (Ea or El, under Al, 13), eka-manganese (Em, under Mn, 25), and eka-silicon (Es, under Si, 14), proved to be good predictors of the properties of scandium (Sc, 21), gallium (Ga, 31), technetium (Tc, 43), and germanium (Ge, 32) respectively, each of which fill the spot in the periodic table assigned by Mendeleev. The names were written by Dmitri Mendeleev as (ekaborʺ), (ekaaljuminij), (ekamarganecʺ), and (ekasilicij) respectively, following the pre-1917 Russian orthography. Initial versions of the periodic table did not distinguish rare earth elements from transition elements, helping to explain both why Mendeleev's predictions for heavier unknown elements did not fare as well as those for the lighter ones and why they are not as well known or documented. Scandium oxide was isolated in late 1879 by Lars Fredrick Nilson; Per Teodor Cleve recognized the correspondence and notified Mendeleev late in that year. Mendeleev had predicted an atomic mass of 44 for eka-boron in 1871, while scandium has an atomic mass of 44.955908. In 1871, Mendeleev predicted the existence of a yet-undiscovered element he named eka-aluminium (because of its proximity to aluminium in the periodic table). The table below compares the qualities of the element predicted by Mendeleev with actual characteristics of gallium, which was discovered, soon after Mendeleev predicted its existence, in 1875 by Paul Emile Lecoq de Boisbaudran. Technetium was isolated by Carlo Perrier and Emilio Segrè in 1937, well after Mendeleev's lifetime, from samples of molybdenum that had been bombarded with deuterium nuclei in a
Mendeleev's predicted elements
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Christian Wilhelm Blomstrand (20 October 1826 – 5 November 1897) was a Swedish mineralogist and chemist. He was a professor at the University of Lund from 1862-1895, where he isolated the element niobium in 1864. He developed an early version of the periodic table and made advances in understanding the chemistry of coordination compounds. Blomstrand published textbooks in chemistry and was well-known internationally for his scientific contributions. Education and career Blomstrand was born in Växjö, Sweden to his father John Blomstrand, who was a teacher, and his wife Severina Rodhe. Blomstrand studied mineralogy at the University of Lund, where he earned a philosophy degree in 1850. He then became interested in chemistry and was the first recipient of the Berzelius scholarship. In 1854, he completed his habilitation for research on bromine and iodine compounds of tin. With the exception of lecturing at the Elementary Technical School of Malmö in 1855 and working as a mineralogist on an expedition to Spitsbergen in 1861, Blomstrand's entire career was at the University of Lund. Blomstrand was appointed an adjunct lecturer and laboratory demonstrator in chemistry at the University of Lund in 1856. He became a member of the Royal Swedish Academy of Sciences in 1861. He became a professor of chemistry and mineralogy at Lund in 1862, remaining there until his retirement in 1895. He served as rector of the university from 1871-1872. The elements Blomstrand's experimental research involved the characterization and analysis of minerals, particularly those which were rare or of unknown composition. These included euxenite, ilmenite, monazite, niobite, and tantalite. He focused on the chemical analysis of what are now known as the group Vb subgroup of Group 5 elements. These "earth acids" include the elements tantalum, niobium, molybdenum, tungsten, and their various mineral associates. In 1864, Blomstrand was the first person to successfully obtain the element niobium in pure form. Blomstrand had been studying various metal chlorides, and he identified the oxychloride of niobium, NbOCl3 as part of this investigation. He then isolated niobium by placing niobium chloride in an atmosphere of hydrogen and heating it. In that way, he obtained pure metallic niobium as a steel-gray material. Niobium had previously been discovered in 1801 by English scientist Charles Hatchett, using an ore obtained from the United States. Hackett named the element Columbium, only being renamed Niobium in 1950. However, the element was not obtained in pure form until Blomstrand conducted his investigations. In 1870, Blomstrand proposed a new way of systematizing the elements, a "natural system" based on atomicity (the ability of elements to combine with other elements) and the electrochemical properties of the element. Organizing the elements into subgroups of even and odd atomicity revealed "extraordinary regularities". While Blomsrand's system was a significant advance toward developing a periodic table of the elements, it did not account well for metals. Blomstrand included his system in his revised edition of Nils Johan Berlins popular textbook in 1870, and in his own textbooks in 1873 and 1875. Dmitri Mendeleev, later credited
Christian Wilhelm Blomstrand
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the etymology of chemical elements of the periodic table. History Throughout the history of chemistry, several chemical elements have been discovered. In the nineteenth century, Dmitri Mendeleev formulated the periodic table, a table of elements which describes their structure. Because elements have been discovered at various times and places, from antiquity through the present day, their names have derived from several languages and cultures. Named after places Forty-one of the 118 chemical elements have names associated with, or specifically named for, places around the world or among astronomical objects. Thirty-two of these have names tied to the places on the Earth and the other nine have names connected to bodies in the Solar System: helium for the Sun; tellurium for the Earth; selenium for the Moon; mercury (indirectly), uranium, neptunium and plutonium for the major planets (note: Pluto was still considered a planet at the time of plutonium's naming); cerium for the dwarf planet Ceres (also considered a planet at the time of naming) and palladium for the asteroid Pallas. Named after people Nineteen elements are connected with the names of twenty people (as curium honours both Marie and Pierre Curie). Fifteen elements were named after scientists; four other have indirect connection to the names of non-scientists. Only gadolinium and samarium occur in nature; the rest are synthetic. Glenn T. Seaborg and Yuri Oganessian were the only two who were alive at the time of being honored with having elements named after them, and Oganessian is the only one still living. Elements named after four non-scientists in this table were actually named for a place or thing which in turn had been named for these people: Samarium was named for the mineral samarskite from which it was isolated. Berkelium and livermorium are named after cities of Berkeley, California and Livermore, California are the locations of the University of California Radiation Laboratory and Lawrence Livermore National Laboratory, respectively. Americium is indirectly connected to Amerigo Vespucci via America. Named after mythological entities Also, mythological entities have had a significant impact on the naming of elements, directly or indirectly. Cerium, europium, helium, iridium, mercury, neptunium, niobium, palladium, plutonium, promethium, selenium, titanium, thorium, uranium and vanadium and all connected to mythological deities. Named after minerals Elements may also have been named after minerals (in which they were discovered). For example, beryllium is named after beryl. Controversies and failed proposals Other element names given after people have been proposed but failed to gain official international recognition. These include columbium (Cb), hahnium (Ha), joliotium (Jl), and kurchatovium (Ku), names connected to Christopher Columbus, Otto Hahn, Irène Joliot-Curie, and Igor Kurchatov; and also cassiopeium (Cp), a name coming from the constellation Cassiopeia and is hence indirectly connected to the mythological Cassiopeia. Current naming practices and procedures For the last two decades, IUPAC has been the governing body for naming elements. IUPAC has also provided a temporary name and symbol for unknown or recently synthesized elements. List See also List of chemical elements naming controversies Naming of elements
List of chemical element name etymologies
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Max Joseph Pettenkofer, ennobled in 1883 as Max Joseph von Pettenkofer (3 December 1818 – 10 February 1901) was a Bavarian chemist and hygienist. He is known for his work in practical hygiene, as an apostle of good water, fresh air and proper sewage disposal. He was further known as an anti-contagionist, a school of thought, named later on, that did not believe in the then novel concept that bacteria were the main cause of disease. In particular he argued in favor of a variety of conditions collectively contributing to the incidence of disease including: personal state of health, the fermentation of environmental ground water, and also the germ in question. He was most well known for his establishment of hygiene as an experimental science and also was a strong proponent for the founding of hygiene institutes in Germany. His work served as an example which other institutes around the world emulated. Early life and education Pettenkofer was born in Lichtenheim, near Neuburg an der Donau, now part of Weichering. He was a nephew of Franz Xaver (1783–1850), who from 1823 was a surgeon and apothecary to the Bavarian court and was the author of some chemical investigations on the vegetable alkaloids. After a falling out with a relative he was staying with he briefly entered the theater. He returned to his family to marry Helene Pettenkofer. A stipulation of his marriage was that he pursue another career and was advised to pursue medicine. He attended the Wilhelmsgymnasium, in Munich, then studied pharmacy and medicine at the Ludwig Maximilian University, where he graduated M.D. in 1845. Career as chemist After working under Liebig at Gießen, Pettenkofer was appointed chemist to the Munich mint in 1845. Two years later he was chosen as an extraordinary professor of chemistry at the medical faculty. In 1853 he was made a full professor and in 1865 he also became a professor of hygiene. In his earlier years he devoted himself to chemistry, both theoretical and applied, publishing papers on a wide range of topics. One of his first projects and subsequent publications was in the separation of gold, silver, and platinum. This work derived from his position at the Munich mint and was centered around minimizing the costs of currency conversion by separating the precious metals from one another. The purer elements could then be utilized in other applications. Later in his career he continued published and spoke about the numerical relations between the atomic masses of analogous elements. His theories were early in the development of the Periodic Table. He rejected the current theory of triads and expanded the connections between the elements to larger groupings. He argued that the weights of different elements in a group were separated by multiples of a certain number that varied based upon the group. His work in this area was later cited by Dmitri Mendeleev in his construction of the Periodic Table of Elements. He continued his publications in a wide variety of other fields as
Max Joseph von Pettenkofer
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A synthetic element is one of 24 known chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called "synthetic", "artificial", or "man-made". The synthetic elements are those with atomic numbers 95–118, as shown in purple on the accompanying periodic table: these 24 elements were first created between 1944 and 2010. The mechanism for the creation of a synthetic element is to force additional protons into the nucleus of an element with an atomic number lower than 95. All known (see: Island of stability) synthetic elements are unstable, but they decay at widely varying rates: the half-lives of their longest-lived isotopes range from microseconds to millions of years. Five more elements that were first created artificially are strictly speaking not synthetic because they were later found in nature in trace quantities: 43Tc, 61Pm, 85At, 93Np, and 94Pu, though are sometimes classified as synthetic alongside exclusively artificial elements. The first, technetium, was created in 1937. Plutonium (Pu, atomic number 94), first synthesized in 1940, is another such element. It is the element with the largest number of protons (atomic number) to occur in nature, but it does so in such tiny quantities that it is far more practical to synthesize it. Plutonium is known mainly for its use in atomic bombs and nuclear reactors. No elements with atomic numbers greater than 99 have any uses outside of scientific research, since they have extremely short half-lives, and thus have never been produced in large quantities. Properties All elements with atomic number greater than 94 decay quickly enough into lighter elements such that any atoms of these that may have existed when the Earth formed (about 4.6 billion years ago) have long since decayed. Synthetic elements now present on Earth are the product of atomic bombs or experiments that involve nuclear reactors or particle accelerators, via nuclear fusion or neutron absorption. Atomic mass for natural elements is based on weighted average abundance of natural isotopes in Earth's crust and atmosphere. For synthetic elements, there is no "natural isotope abundance". Therefore, for synthetic elements the total nucleon count (protons plus neutrons) of the most stable isotope, i.e., the isotope with the longest half-life—is listed in brackets as the atomic mass. History Technetium The first element to be synthesized, rather than discovered in nature, was technetium in 1937. This discovery filled a gap in the periodic table, and the fact that technetium has no stable isotopes explains its natural absence on Earth (and the gap). With the longest-lived isotope of technetium, 97Tc, having a 4.21-million-year half-life, no technetium remains from the formation of the Earth. Only minute traces of technetium occur naturally in Earth's crust—as a product of spontaneous fission of 238U, or from neutron capture in molybdenum—but technetium is present naturally in red giant stars. Curium The first entirely synthetic element to be made was curium, synthesized in
Synthetic element
199077
A period 2 element is one of the chemical elements in the second row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number increases; a new row is started when chemical behavior begins to repeat, creating columns of elements with similar properties. The second period contains the elements lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, and neon. In a quantum mechanical description of atomic structure, this period corresponds to the filling of the second () shell, more specifically its 2s and 2p subshells. Period 2 elements (carbon, nitrogen, oxygen, fluorine and neon) obey the octet rule in that they need eight electrons to complete their valence shell (lithium and beryllium obey duet rule, boron is electron deficient.), where at most eight electrons can be accommodated: two in the 2s orbital and six in the 2p subshell. Periodic trends Period 2 is the first period in the periodic table from which periodic trends can be drawn. Period 1, which only contains two elements (hydrogen and helium), is too small to draw any conclusive trends from it, especially because the two elements behave nothing like other s-block elements. Period 2 has much more conclusive trends. For all elements in period 2, as the atomic number increases, the atomic radius of the elements decreases, the electronegativity increases, and the ionization energy increases. Period 2 only has two metals (lithium and beryllium) of eight elements, less than for any subsequent period both by number and by proportion. It also has the most number of nonmetals, namely five, among all periods. The elements in period 2 often have the most extreme properties in their respective groups; for example, fluorine is the most reactive halogen, neon is the most inert noble gas, and lithium is the least reactive alkali metal. All period 2 elements completely obey the Madelung rule; in period 2, lithium and beryllium fill the 2s subshell, and boron, carbon, nitrogen, oxygen, fluorine, and neon fill the 2p subshell. The period shares this trait with periods 1 and 3, none of which contain transition elements or inner transition elements, which often vary from the rule. {| | colspan="3" | Chemical element || Block || Electron configuration |-bgcolor="" || 3 || Li || Lithium || s-block || [He] 2s1 |-bgcolor="" || 4 || Be || Beryllium || s-block || [He] 2s2 |-bgcolor="" || 5 || B || Boron || p-block || [He] 2s2 2p1 |-bgcolor="" || 6 || C || Carbon || p-block || [He] 2s2 2p2 |-bgcolor="" || 7 || N || Nitrogen || p-block || [He] 2s2 2p3 |-bgcolor="" || 8 || O || Oxygen || p-block || [He] 2s2 2p4 |-bgcolor="" || 9 || F || Fluorine || p-block || [He] 2s2 2p5 |-bgcolor="" || 10 || Ne || Neon || p-block || [He] 2s2 2p6 |} Lithium Lithium (Li) is an alkali metal with atomic number
Period 2 element
46736756
The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements, is a 2010 book by science reporter Sam Kean. The book was first published in hardback on July 12, 2010 through Little, Brown and Company and was released in paperback on June 6, 2011 through Little, Brown and Company's imprint Back Bay Books. The book focuses on the history of the periodic table by way of short stories showing how a number of chemical elements affected their discoverers, for either good or bad. People discussed in the book include the physicist and chemist Marie Curie, whose discovery of radium almost ruined her career; the writer Mark Twain, whose short story "Sold to Satan" featured a devil who was made of radium and wore a suit made of polonium; and the theoretical physicist Maria Goeppert-Mayer, who earned a Nobel Prize in Physics for her groundbreaking work, yet continually faced opposition owing to her sex. Contents Chapter 1. Geography of elements Sam Kean begins this book by explaining the basics of the periodic table and how it works. He explains the set-up of the table and why it is organized the way it is. He emphasizes the importance of its organization and justifies why it must be this way. He discusses how the periodic table would not function if it were not for the layout. He states that an element's position describes its function and strength. He describes the table of elements as a castle and the elements as bricks to build this castle. He then discusses how the periodic table contains, and is organized into, metals, gases, noble gases, halogens, etc. Kean also discusses how ions work overall. He describes how ions are made when atoms connect with electrons by either giving electrons or taking electrons to another molecule to obtain a net electrical charge. He states the importance the net electrical charge has on the elements and the periodic table placement. He covers the electron shells and how certain elements hide electrons and do not share and, while others do share. Kean describes electron behavior as being the guiding point to what forms the period table. Toward the end of this chapter, he speaks of Maria Goeppert-Mayer and her contributions to science. Chapter 2. The fathers of the periodic table The author focuses on the relationships between carbon, silicon, and germanium. He explains how carbon is the backbone of amino acids and the building blocks to everything. He discusses that because of carbon, amino acids all stick together. Then, he describes the carbon element and how it wants to fill its outer energy level with eight electrons so it attaches to four atoms since carbon already has four electrons. Next, Kean describes silicon. In general, he states that they are cousins because silicon mimics carbon in the sense that it also seeks to attach to four more atoms to fill its energy levels. The big issue that
The Disappearing Spoon
181556
A period 6 element is one of the chemical elements in the sixth row (or period) of the periodic table of the chemical elements, including the lanthanides. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The sixth period contains 32 elements, tied for the most with period 7, beginning with caesium and ending with radon. Lead is currently the last stable element; all subsequent elements are radioactive. For bismuth, however, its only primordial isotope, 209Bi, has a half-life of more than 1019 years, over a billion times longer than the current age of the universe. As a rule, period 6 elements fill their 6s shells first, then their 4f, 5d, and 6p shells, in that order; however, there are exceptions, such as gold. Properties This period contains the lanthanides, also known as the rare earths. Many lanthanides are known for their magnetic properties, such as neodymium. Many period 6 transition metals are very valuable, such as gold, however many period 6 other metals are incredibly toxic, such as thallium. Period 6 contains the last stable element, lead. All subsequent elements in the periodic table are radioactive. After bismuth, which has a half-life or more than 1019 years, polonium, astatine, and radon are some of the shortest-lived and rarest elements known; less than a gram of astatine is estimated to exist on earth at any given time. Atomic characteristics {| class="wikitable sortable" ! colspan="3" | Chemical element ! Block ! Electron configuration |- bgcolor="" || 55 || Cs || Caesium || s-block || [Xe] 6s1 |- bgcolor="" || 56 || Ba || Barium || s-block || [Xe] 6s2 |- bgcolor="" || 57 || La || Lanthanum || f-block || [Xe] 5d1 6s2 |- bgcolor="" || 58 || Ce || Cerium || f-block || [Xe] 4f1 5d1 6s2 |- bgcolor="" || 59 || Pr || Praseodymium || f-block || [Xe] 4f3 6s2 |- bgcolor="" || 60 || Nd || Neodymium || f-block || [Xe] 4f4 6s2 |- bgcolor="" || 61 || Pm || Promethium || f-block || [Xe] 4f5 6s2 |- bgcolor="" || 62 || Sm || Samarium || f-block || [Xe] 4f6 6s2 |- bgcolor="" || 63 || Eu || Europium || f-block || [Xe] 4f7 6s2 |- bgcolor="" || 64 || Gd || Gadolinium || f-block || [Xe] 4f7 5d1 6s2 |- bgcolor="" || 65 || Tb || Terbium || f-block || [Xe] 4f9 6s2 |- bgcolor="" || 66 || Dy || Dysprosium || f-block || [Xe] 4f10 6s2 |- bgcolor="" || 67 || Ho || Holmium || f-block || [Xe] 4f11 6s2 |- bgcolor="" || 68 || Er || Erbium || f-block || [Xe] 4f12 6s2 |- bgcolor="" || 69 || Tm || Thulium || f-block || [Xe] 4f13 6s2 |- bgcolor="" || 70 || Yb || Ytterbium ||
Period 6 element
195729
A period 3 element is one of the chemical elements in the third row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number increases: a new row is begun when chemical behavior begins to repeat, meaning that elements with similar behavior fall into the same vertical columns. The third period contains eight elements: sodium, magnesium, aluminium, silicon, phosphorus, sulfur, chlorine and argon. The first two, sodium and magnesium, are members of the s-block of the periodic table, while the others are members of the p-block. All of the period 3 elements occur in nature and have at least one stable isotope. Atomic structure In a quantum mechanical description of atomic structure, this period corresponds to the buildup of electrons in the third () shell, more specifically filling its 3s and 3p subshells. There is a 3d subshell, but—in compliance with the Aufbau principle—it is not filled until period 4. This makes all eight elements analogs of the period 2 elements in the same exact sequence. The octet rule generally applies to period 3 in the same way as to period 2 elements, because the 3d subshell is normally non-acting. Elements Sodium Sodium (symbol Na) is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals such as feldspars, sodalite and rock salt. Many salts of sodium are highly soluble in water and are thus present in significant quantities in the Earth's bodies of water, most abundantly in the oceans as sodium chloride. Many sodium compounds are useful, such as sodium hydroxide (lye) for soapmaking, and sodium chloride for use as a deicing agent and a nutrient. The same ion is also a component of many minerals, such as sodium nitrate. The free metal, elemental sodium, does not occur in nature but must be prepared from sodium compounds. Elemental sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Magnesium Magnesium (symbol Mg) is an alkaline earth metal and has common oxidation number +2. It is the eighth most abundant element in the Earth's crust and the ninth in the known universe as a whole. Magnesium is the fourth most common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet's mass and a large fraction of the planet's mantle. It is relatively abundant because it is easily built up in supernova stars by sequential additions of three helium nuclei to carbon (which in turn is made from three helium nuclei). Due to the magnesium ion's high solubility in water, it is the third most abundant element dissolved in seawater. The free element (metal) is not found naturally on Earth, as it is highly reactive (though once produced, it is coated in a
Period 3 element
76350521
Daniel Allen Cohen is a Los Angeles-based multi-media artist best known for his platform, This is Addictive, which highlights adult cravings and material obsessions using imagery often associated with childhood nostalgia. His series, Periodic Table of Drugs, parodies the format of the scientific periodic table but instead of cataloguing natural elements, Cohen catalogues a variety of narcotics. Cohen has shown his work at art fairs including SCOPE Art Show in Miami and the L.A. Art Show. In 2021, Cohen released his first non-fungible token art on Nifty Gateway's digital marketplace. Work Made from a variety of materials, including: wood, acrylic paint, metal, graphic design and digital alterations, Cohen's work satirizes consumer habits associated with youth culture in Western society. Incorporating substances, such as drugs, chocolate and diamonds, that are associated with decadence and often abused, Cohen is able to address the glamorization of addiction. Score (2015) In this series, Cohen comments on the increase of drug use, and ease of its availability, in the United States. Using the format of a nutrition label that lists ingredients in packaged food, he lists the effects of recreational drugs. In addition to creating these labels for actual drugs, Cohen invents drugs, like "Insta-Fame" pills and "Poor & Suffering Relief" pills. Precious Bars (2016) In 2016, Cohen released his Precious Bars series where he fabricated stacks of money and gold bars wrapped in the packaging of branded chocolate bars that were altered slightly. The iconic Mr. Goodbar, in Cohen's version, was changed to "Mr. Goldbar." Periodic Table of Drugs (2017) In this ongoing series, Cohen parodies the Periodic Table of Elements which outlines life-sustaining elements like Hydrogen, Carbon, Nitrogen and Oxygen. By featuring recreational drugs instead of chemical elements, Cohen illustrates the irony surrounding which substances are valued in contemporary society. References Living people Multimedia artists American artists Contemporary art
Daniel Allen Cohen
30364
In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. The lanthanide and actinide elements (the f-block) are called inner transition metals and are sometimes considered to be transition metals as well. Since they are metals, they are lustrous and have good electrical and thermal conductivity. Most (with the exception of group 11 and group 12) are hard and strong, and have high melting and boiling temperatures. They form compounds in any of two or more different oxidation states and bind to a variety of ligands to form coordination complexes that are often coloured. They form many useful alloys and are often employed as catalysts in elemental form or in compounds such as coordination complexes and oxides. Most are strongly paramagnetic because of their unpaired d electrons, as are many of their compounds. All of the elements that are ferromagnetic near room temperature are transition metals (iron, cobalt and nickel) or inner transition metals (gadolinium). English chemist Charles Rugeley Bury (1890–1968) first used the word transition in this context in 1921, when he referred to a transition series of elements during the change of an inner layer of electrons (for example n = 3 in the 4th row of the periodic table) from a stable group of 8 to one of 18, or from 18 to 32. These elements are now known as the d-block. Definition and classification The 2011 IUPAC Principles of Chemical Nomenclature describe a "transition metal" as any element in groups 3 to 12 on the periodic table. This corresponds exactly to the d-block elements, and many scientists use this definition. In actual practice, the f-block lanthanide and actinide series are called "inner transition metals". The 2005 Red Book allows for the group 12 elements to be excluded, but not the 2011 Principles. The IUPAC Gold Book defines a transition metal as "an element whose atom has a partially filled d sub-shell, or which can give rise to cations with an incomplete d sub-shell", but this definition is taken from an old edition of the Red Book and is no longer present in the current edition. In the d-block, the atoms of the elements have between zero and ten d electrons. Published texts and periodic tables show variation regarding the heavier members of group 3. The common placement of lanthanum and actinium in these positions is not supported by physical, chemical, and electronic evidence, which overwhelmingly favour putting lutetium and lawrencium in those places. Some authors prefer to leave the spaces below yttrium blank as a third option, but there is confusion on whether this format implies that group 3 contains only scandium and yttrium, or if it also contains all the lanthanides and actinides; additionally, it creates a 15-element-wide f-block, when quantum mechanics dictates that the f-block should only be 14 elements wide. The form with lutetium and lawrencium
Transition metal
48423956
Henry D. Hubbard (1870-1943) was a member of the U.S. Bureau of Standards in the 1920s. He modernized Mendeleev's periodic table and in 1924 he produced a version of the Periodic Table of Elements (called the Periodic Chart of the Atoms) which was distributed to schools and universities. His version of the periodic table placed the main groups in columns with some later groups taking up two rows per period and the Group VIIIB transition metals displayed out to the right of the noble gases. The noble gases themselves were shown first in Column 1 (Valence 0) and repeated in Column 9 (Group VIII). The table is also notable for including the solo Neutron as an entry on its own, "above" Hydrogen, and given the symbol lower-case 'n'. Gallery References External links Video about a 1930s Hubbard Periodic table found in the University of Rio de Janeiro, Brazil showing discredited elements 87Virginium, 61Illinium, 85Alabamine and 43Masurium. Year of birth missing Year of death missing People involved with the periodic table United States Department of Commerce officials
Henry D. Hubbard
199079
A period 1 element is one of the chemical elements in the first row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate periodic (recurring) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that analog elements fall into the same vertical columns. The first period contains fewer elements than any other row in the table, with only two: hydrogen and helium. This situation can be explained by modern theories of atomic structure. In a quantum mechanical description of atomic structure, this period corresponds to the filling of the 1s orbital. Period 1 elements obey the duet rule in that they need two electrons to complete their valence shell. Hydrogen and helium are the oldest and the most abundant elements in the universe. Periodic trends All other periods in the periodic table contain at least eight elements, and it is often helpful to consider periodic trends across the period. However, period 1 contains only two elements, so this concept does not apply here. In terms of vertical trends down groups, helium can be seen as a typical noble gas at the head of the IUPAC group 18, but as discussed below, hydrogen's chemistry is unique and it is not easily assigned to any group. Position of period 1 elements in the periodic table The first electron shell, , consists of only one orbital, and the maximum number of valence electrons that a period 1 element can accommodate is two, both in the 1s orbital. The valence shell lacks "p" or any other kind of orbitals due to the general constraint on the quantum numbers. Therefore, period 1 has exactly two elements. Although both hydrogen and helium are in the s-block, neither of them behaves similarly to other s-block elements. Their behaviour is so different from the other s-block elements that there is considerable disagreement over where these two elements should be placed in the periodic table. Simply following electron configurations, hydrogen (electronic configuration 1s1) and helium (1s2) should be placed in groups 1 and 2, above lithium (1s22s1) and beryllium (1s22s2). While such a placement is common for hydrogen, it is rarely used for helium outside of the context of illustrating the electron configurations. Usually, hydrogen is placed in group 1, and helium in group 18: this is the placement found on the IUPAC periodic table. Some variation can be found on both these matters. Like the group 1 metals, hydrogen has one electron in its outermost shell and typically loses its only electron in chemical reactions. It has some metal-like chemical properties, being able to displace some metals from their salts. But hydrogen forms a diatomic nonmetallic gas at standard conditions, unlike the alkali metals which are reactive solid metals. This and hydrogen's formation of hydrides, in which it gains an electron, brings it close to the properties of the halogens which
Period 1 element
26344581
In chemistry and physics, the iron group refers to elements that are in some way related to iron; mostly in period (row) 4 of the periodic table. The term has different meanings in different contexts. In chemistry, the term is largely obsolete, but it often means iron, cobalt, and nickel, also called the iron triad; or, sometimes, other elements that resemble iron in some chemical aspects. In astrophysics and nuclear physics, the term is still quite common, and it typically means those three plus chromium and manganese—five elements that are exceptionally abundant, both on Earth and elsewhere in the universe, compared to their neighbors in the periodic table. Titanium and vanadium are also produced in Type Ia supernovae. General chemistry In chemistry, "iron group" used to refer to iron and the next two elements in the periodic table, namely cobalt and nickel. These three comprised the "iron triad". They are the top elements of groups 8, 9, and 10 of the periodic table; or the top row of "group VIII" in the old (pre-1990) IUPAC system, or of "group VIIIB" in the CAS system. These three metals (and the three of the platinum group, immediately below them) were set aside from the other elements because they have obvious similarities in their chemistry, but are not obviously related to any of the other groups. The iron group and its alloys exhibit ferromagnetism. The similarities in chemistry were noted as one of Döbereiner's triads and by Adolph Strecker in 1859. Indeed, Newlands' "octaves" (1865) were harshly criticized for separating iron from cobalt and nickel. Mendeleev stressed that groups of "chemically analogous elements" could have similar atomic weights as well as atomic weights which increase by equal increments, both in his original 1869 paper and his 1889 Faraday Lecture. Analytical chemistry In the traditional methods of qualitative inorganic analysis, the iron group consists of those cations which have soluble chlorides; and are not precipitated as sulfides by hydrogen sulfide in acidic conditions; are precipitated as hydroxides at around pH 10 (or less) in the presence of ammonia. The main cations in the iron group are iron itself (Fe2+ and Fe3+), aluminium (Al3+) and chromium (Cr3+). If manganese is present in the sample, a small amount of hydrated manganese dioxide is often precipitated with the iron group hydroxides. Less common cations which are precipitated with the iron group include beryllium, titanium, zirconium, vanadium, uranium, thorium and cerium. Astrophysics The iron group in astrophysics is the group of elements from chromium to nickel, which are substantially more abundant in the universe than those that come after them – or immediately before them – in order of atomic number. The study of the abundances of iron group elements relative to other elements in stars and supernovae allows the refinement of models of stellar evolution. The explanation for this relative abundance can be found in the process of nucleosynthesis in certain stars, specifically those of about 8–11 Solar masses. At the end of their lives, once other
Iron group
8200
The discoveries of the 118 chemical elements known to exist as of 2024 are presented here in chronological order. The elements are listed generally in the order in which each was first defined as the pure element, as the exact date of discovery of most elements cannot be accurately determined. There are plans to synthesize more elements, and it is not known how many elements are possible. Each element's name, atomic number, year of first report, name of the discoverer, and notes related to the discovery are listed. Periodic table of elements Graphical timeline Cumulative diagram Pre-modern and early modern discoveries Modern discoveries For 18th-century discoveries, around the time that Antoine Lavoisier first questioned the phlogiston theory, the recognition of a new "earth" has been regarded as being equivalent to the discovery of a new element (as was the general practice then). For some elements (e.g. Be, B, Na, Mg, Al, Si, K, Ca, Mn, Co, Ni, Zr, Mo), this presents further difficulties as their compounds were widely known since medieval or even ancient times, even though the elements themselves were not. Since the true nature of those compounds was sometimes only gradually discovered, it is sometimes very difficult to name one specific discoverer. In such cases the first publication on their chemistry is noted, and a longer explanation given in the notes. See also History of the periodic table Periodic table Extended periodic table The Mystery of Matter: Search for the Elements (2014/2015 PBS film) Transfermium Wars References External links History of the Origin of the Chemical Elements and Their Discoverers Last updated by Boris Pritychenko on March 30, 2004 History of Elements of the Periodic Table Timeline of Element Discoveries The Historyscoper Discovery of the Elements – The Movie – YouTube (1:18) The History Of Metals Timeline . A timeline showing the discovery of metals and the development of metallurgy. —Eric Scerri, 2007, The periodic table: Its story and its significance, Oxford University Press, New York, Elements, discoveries Timeline History of chemistry History of physics Discovery
Discovery of chemical elements
9118221
Theodore W. "Theo" Gray is a co-founder of Wolfram Research, science author, and co-founder of app developer Touch Press. Education Theodore Gray was educated at the University of Illinois Laboratory High School. He would later graduate with a B.S. in chemistry from University of Illinois at Urbana–Champaign in 1986. Career In 1987, Gray left a PhD program in theoretical chemistry at the University of California at Berkeley to work with Stephen Wolfram. In that same year, he co-founded Wolfram Research. His initial work for the company involved creating the influential notebook user interface for Mathematica. Gray would eventually leave Wolfram Research to become a writer and publisher full-time. After amassing thousands of samples of elements, he assembled them into a four-legged physical table representing the periodic table. The finished table was awarded the 2011 ACS Grady Stack Award for Interpreting Chemistry for the Public, as well as the 2002 Ig Nobel Award for Chemistry. Gray's love of the periodic table would lead him to team up with photographer Nick Mann in creating The Elements: A Visual Exploration of Every Known Atom in the Universe and Elements Vault. For many years, Gray wrote a regular column for Popular Science entitled "Gray Matter". The column was a finalist for a National Magazine Award for Best Column in 2010. In 2009, a collection of articles by Gray was published under the title Mad Science: Experiments You Can Do at Home—But Probably Shouldn't. A sequel to the book, Mad Science 2: Experiments You Can Do At Home, But STILL Probably Shouldn't was published in 2013. In 2010, Gray founded Touch Press together with Max Whitby, John Cromie and Stephen Wolfram shortly after the announcement of the launch of the iPad. The company was created to develop innovative educational apps using the technology of the iPad to its full potential. The first published app was "The Elements," and in 2014 Gray released "Molecules", which allows users to touch and discover the basic building blocks of the world. Of Touch Press's "Disney Animated," which was named the best iPad app of 2013 worldwide by Apple, iTunes's App Editor noted, "We’re absolutely spellbound". The app won a BAFTA award in 2014. Gray also co-founded Pale Gray Labs with Nina Paley. Gray has developed a range of acrylic model kits, which he named "Mechanical GIFs" (as a nod to animated drawings on the internet), to show "how common and uncommon machines, mechanisms, gadgets, and devices work". In July 2018, Gray was invited to Beijing on behalf of The Newton Project by its founder, Jizhe Xu, to serve as a consulting advisor. Throughout his career, Gray has been an advocate for a broader engagement between the scientific community and the public at large. Works How Things Work: The Inner Life of Everyday Machines, Black Dog & Leventhal Publishers, 2019, 256pp. Reactions: An Illustrated Exploration of Elements, Molecules, and Change in the Universe, Black Dog & Leventhal, 2017, 240pp. Molecules: The Elements and the Architecture of Everything, Black Dog &
Theodore Gray
8936720
A table or chart of nuclides is a two-dimensional graph of isotopes of the elements, in which one axis represents the number of neutrons (symbol N) and the other represents the number of protons (atomic number, symbol Z) in the atomic nucleus. Each point plotted on the graph thus represents a nuclide of a known or hypothetical chemical element. This system of ordering nuclides can offer a greater insight into the characteristics of isotopes than the better-known periodic table, which shows only elements and not their isotopes. The chart of the nuclides is also known as the Segrè chart, after the Italian physicist Emilio Segrè. Description and utility A chart or table of nuclides maps the nuclear, or radioactive, behavior of nuclides, as it distinguishes the isotopes of an element. It contrasts with a periodic table, which only maps their chemical behavior, since isotopes (nuclides which are variants of the same element) do not differ chemically to any significant degree, with the exception of hydrogen. Nuclide charts organize nuclides along the X axis by their numbers of neutrons and along the Y axis by their numbers of protons, out to the limits of the neutron and proton drip lines. This representation was first published by Kurt Guggenheimer in 1934 and expanded by Giorgio Fea in 1935, Emilio Segrè in 1945 or Glenn Seaborg. In 1958, Walter Seelmann-Eggebert and Gerda Pfennig published the first edition of the Karlsruhe Nuclide Chart. Its 7th edition was made available in 2006. Today, there are several nuclide charts, four of which have a wide distribution: the Karlsruhe Nuclide Chart, the Strasbourg Universal Nuclide Chart, the Chart of the Nuclides from the Japan Atomic Energy Agency (JAEA), and the Nuclide Chart from Knolls Atomic Power Laboratory in the United States. It has become a basic tool of the nuclear community. Trends in the chart of nuclides The trends in this section refer to the following chart, which shows Z increasing to the right and N increasing downward, a 90° clockwise rotation of the above landscape-orientation charts. Isotopes are nuclides with the same number of protons but differing numbers of neutrons; that is, they have the same atomic number and are therefore the same chemical element. Isotopes neighbor each other vertically. Examples include carbon-12, carbon-13, and carbon-14 in the table above. Isotones are nuclides with the same number of neutrons but differing numbers of protons. Isotones neighbor each other horizontally. Examples include carbon-14, nitrogen-15, and oxygen-16 in the table above. Isobars are nuclides with the same number of nucleons (i.e. mass number) but different numbers of protons and neutrons. Isobars neighbor each other diagonally from lower-left to upper-right. Examples include carbon-14, nitrogen-14, and oxygen-14 in the table above. Isodiaphers are nuclides with the same difference between their numbers of neutrons and protons (N − Z). Like isobars, they follow diagonal lines, but at right angles to the isobar lines (from upper-left to lower-right). Examples include boron-10, carbon-12, and nitrogen-14 (as N − Z = 0 for each
Table of nuclides
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Just how far back in history organized contests were held remains a matter of debate, but it is reasonably certain that they occurred in Greece almost 3,000 years ago. However ancient in origin, by the end of the 6th century BC at least four Greek sporting festivals, sometimes called "classical games," had achieved major importance: the Olympic Games, held at Olympia; the Pythian Games at Delphi; the Nemean Games at Nemea; and the Isthmian Games, held near Corinth. The Olympic Games were perhaps the greatest of these sporting events, and all Olympian victors were highly appreciated among the Greeks. History The sophist Hippias of Elis was the first who drew up the list of Olympians in his work Olympians inscription, based perhaps on the records of Olympia, and the oral tradition memories of the older Olympiads were still live in Olympia. Conventional beginning was considered the Olympiad of 776 BC, when Coroebus of Elis win the foot race named stadion. The work of Hippias revised and continued in the 4th century BC by Aristotle, later by Eratosthenes, then by Phlegon of Tralles (Seleucia of Caria) and many others. Thus formed a kind of Olympians' chronicle, which was already in 3rd century BC the base of the ancient dating system. Than younger tables survives complete the list of stadion winners by Sextus Julius Africanus (for the first 249 Olympiads), which included in a book by Eusebius of Caesarea. List of Olympic winners in the Archaic period The table below is an attempt to give a list (as complete as possible) of Olympic winners in the Archaic period (776 BC to 480 BC) combining all surviving sources. The work is based on records in the surviving historical and literary sources, race inscriptions, the texts of the Oxyrhynchus Papyri, the testimony of Pausanias and the list of Sextus Julius Africanus. The first column shows the serial number of any Olympiad, the second column the same date, the third column contains the game and the fourth column lists the name and origin of the winner, or marked with [...] if the element is not readable on the papyrus and giving whenever possible a version of what could contain when an investigation exists over this element. Supplementary list The supplementary list contains Olympic winners of this period known from literary and epigraphic records, but who have been dated only approximately and cannot be included in specific Olympiads. Notes References Sources See also List of ancient olympic victors Ancient Olympics in various places Olive wreath Olympic judges Lists of Olympic medalists Ancient Olympic Games . Lists of ancient Greek people
Olympic winners of the Archaic period
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Since Dimitri Mendeleev formulated the periodic law in 1871, and published an associated periodic table of chemical elements, authors have experimented with varying types of periodic tables including for teaching, aesthetic or philosophical purposes. Earlier, in 1869, Mendeleev had mentioned different layouts including short, medium, and even cubic forms. It appeared to him that the latter (three-dimensional) form would be the most natural approach but that "attempts at such a construction have not led to any real results". On spiral periodic tables, "Mendeleev...steadfastly refused to depict the system as [such]...His objection was that he could not express this function mathematically." Typology In 1934, George Quam, a chemistry professor at Long Island University, New York, and Mary Quam, a librarian at the New York Public Library compiled and published a bibliography of 133 periodic tables using a five-fold typology: I. short; II. long (including triangular); III. spiral; IV. helical, and V. miscellaneous. In 1952, Moeller expressed disdain as to the many types of periodic table: In 1954, Tomkeieff referred to the three principle types of periodic table as helical, rectilinear, and spiral. He added that, "unfortunately there also a number of freaks". In 1974 Edward Mazurs, a professor of chemistry, published a survey and analysis of about seven hundred periodic tables that had been published in the preceding one hundred years; he recognized short, medium, long, helical, spiral, series tables, and tables not classified. In 1999 Mark Leach, a chemist, inaugurated the INTERNET database of Periodic Tables. It has over 1200 entries as of May 2023. While the database is a chronological compilation, specific types of periodic tables that can be searched for are spiral and helical; 3-dimensional; and miscellaneous. For convenience, periodic tables may be typified as either: 1. short; 2. triangular; 3. medium; 4. long; 5. continuous (circular, spiral, lemniscate, or helical); 6. folding; or 7. spatial. Tables that defy easy classification are counted as type 8. unclassified. Short Short tables have around eight columns. This form became popular following the publication of Mendeleev's eight-column periodic table in 1871. Also shown in this section is a modernized version of the same table. Mendeleev and others who discovered chemical periodicity in the 1860s had noticed that when the elements were arranged in order of their atomic weights there was as an approximate repetition of physiochemical properties after every eight elements. Consequently, Mendeleev organized the elements known at that time into a table with eight columns. He used the table to predict the properties of then unknown elements. While his hit rate was less than 50% it was his successes that propelled the widespread acceptance of the idea of a periodic table of the chemical elements. The eight-column style remains popular to this day, most notably in Russia, Mendeleev's country of birth. An earlier attempt by Newlands, an English chemist, to present the nub of the same idea to the London Chemical Society, in 1866, was unsuccessful; members were less than receptive to theoretical ideas, as was the British tendency at
Types of periodic tables
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Periodic Videos (also known as The Periodic Table of Videos) is a video project and YouTube channel on chemistry. It consists of a series of videos about chemical elements and the periodic table, with additional videos on other topics in chemistry and related fields. They are published on YouTube and produced by Brady Haran, a former BBC video journalist, mainly featuring Sir Martyn Poliakoff, Peter Licence, Stephen Liddle, Debbie Kays, Neil Barnes, Sam Tang, and other scientists at the University of Nottingham. Development The project began recording on 9 June 2008 and the initial videos were completed on 17 July 2008. The collection includes videos, each just a few minutes long, for all 118 known elements with a video for each element, as well as many additional supplemental chemistry videos. The 118 element videos and introduction videos were all shot unscripted in June and July 2008. Since the initial videos were completed in 2008 the team has been refining and uploading revised versions of the videos with new video and in higher resolutions. A key example of this revising is with the xenon video that was redone in honour of professor Neil Bartlett who died on 5 August 2008; Bartlett prepared one of the first xenon compounds, xenon hexafluoroplatinate. Content Poliakoff is the most visible presenter on the videos; his hair, reminiscent of Albert Einstein or a mad scientist, is frequently commented upon. The combination of the professor's hair and amusing experiments has made these videos quite popular. Although uncertain what to think about the attention given to his hair, Professor Poliakoff is excited with the success of the videos, stating "With a few hours of work, I have lectured to more students than I have reached in my entire career." The YouTube channel as of December 2021, has over 1.5 million subscribers and the videos have surpassed 260 million views. The YouTube channel is now one of the most popular chemistry related channels on all of YouTube. The producers of the videos have received praise from Nobel Laureates, chemistry professors, and the general public, says Professor Poliakoff. Chemistry Nobel Laureate Roald Hoffmann has even offered his praise of the videos, stating they "are like the best reality show I've ever seen – the universe revealing itself, element by element." In 2019, Poliakoff was awarded the Royal Society of London Michael Faraday Prize for science communication for his work on the videos. The videos feature various experiments and demonstrations of the elements, some too dangerous to be performed in a classroom. Though the presenters take appropriate precautions when doing such experiments and provide adequate warnings, some scientists have criticized the dangerous experiments fearing people might try them at home and get hurt. The intent of the videos is to bring chemistry to a new generation of students and to get them enthused about science and understand how chemists think and what chemists are trying to do. Many school teachers now incorporate these videos into their classes, and the professor has
Periodic Videos
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Yuri Tsolakovich Oganessian ( ; , born 14 April 1933) is a Soviet, Armenian and Russian nuclear physicist who is best known as a researcher of superheavy chemical elements. He participated with the discovery of multiple elements of the periodic table. He succeeded Georgy Flyorov as director of the Flyorov Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research in 1989 and is now its scientific director. The heaviest element known of the periodic table, oganesson, is named after him, only the second time that an element was named after a living person (the other being seaborgium). Personal life Yuri Tsolakovich Oganessian was born in Rostov-on-Don, Russian SFSR, USSR on 14 April 1933 to Armenian parents. His father was from Iğdır (now in Turkey), while his mother was from Armavir in what is now Russia's Krasnodar Krai. Oganessian spent his childhood in Yerevan, the capital of Soviet Armenia, where his family relocated in 1939. His father, Tsolak, a thermal engineer, was invited to work on the synthetic rubber plant in Yerevan. After the Eastern Front of World War II commenced, his family decided to not return to Rostov since it was occupied by Germans. Yuri attended and finished school in Yerevan. He initially wanted to become a painter. Oganessian was married to Irina Levonovna (1932–2010), a violinist and a music teacher in Dubna, with whom he had two daughters. As of 2017, his daughters resided in the U.S. Oganessian speaks Russian, Armenian, and English. Career Oganessian relocated to Russia, where he graduated from the Moscow Engineering Physics Institute (MEPhI) in 1956. He thereafter sought to join the Kurchatov Institute of Atomic Energy in Moscow, but as there were no vacancies left in Gersh Budker's team, he was instead recruited by Georgy Flyorov and began working at the Joint Institute for Nuclear Research (JINR) in Dubna, near Moscow. He became director of the Flyorov Laboratory of Nuclear Reactions at JINR in 1989, after Flyorov retired, and had the job until 1996, when he was named the scientific director of the Flyorov laboratory. Discovery of superheavy chemical elements During the 1970s, Oganessian invented the "cold fusion" method (unrelated to the unproven energy-producing process cold fusion), a technique to produce transactinide elements (superheavy elements). It was crucial for the discoveries of elements from 106 to 113. From the mid-1970s to the mid-1990s, the partnership of JINR, directed by Oganessian, and the GSI Helmholtz Centre for Heavy Ion Research in Germany, resulted in the discovery of six chemical elements (107 to 112): bohrium, meitnerium, hassium, darmstadtium, roentgenium, and copernicium. His newer technique, termed "hot fusion" (also unrelated to nuclear fusion as an energy process), helped to discover elements 113 to 118, completing the seventh row of the periodic table. The technique involved bombarding calcium into targets containing heavier radioactive elements that are rich in neutrons at a cyclotron. The elements discovered using this method are nihonium (2003; also discovered by Riken in Japan using cold fusion), flerovium (1999), moscovium (2003), livermorium (2000),
Yuri Oganessian
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In chemistry, a Zintl phase is a product of a reaction between a group 1 (alkali metal) or group 2 (alkaline earth metal) and main group metal or metalloid (from groups 13, 14, 15, or 16). It is characterized by intermediate metallic/ionic bonding. Zintl phases are a subgroup of brittle, high-melting intermetallic compounds that are diamagnetic or exhibit temperature-independent paramagnetism and are poor conductors or semiconductors. This type of solid is named after German chemist Eduard Zintl who investigated them in the 1930s. The term "Zintl Phases" was first used by Laves in 1941. In his early studies, Zintl noted that there was an atomic volume contraction upon the formation of these products and realized that this could indicate cation formation. He suggested that the structures of these phases were ionic, with complete electron transfer from the more electropositive metal to the more electronegative main group element. The structure of the anion within the phase is then considered on the basis of the resulting electronic state. These ideas are further developed in the Zintl-Klemm-Busmann concept, where the polyanion structure should be similar to that of the isovalent element. Further, the anionic sublattice can be isolated as polyanions (Zintl ions) in solution and are the basis of a rich subfield of main group inorganic chemistry. History A "Zintl Phase" was first observed in 1891 by M. Joannis, who noted an unexpected green colored solution after dissolving lead and sodium in liquid ammonia, indicating the formation of a new product. It was not until many years later, in 1930, that the stoichiometry of the new product was identified as Na4Pb94− by titrations performed by Zintl et al.; and it was not until 1970 that the structure was confirmed by crystallization with ethylenediamine (en) by Kummer. In the intervening years and in the years since, many other reaction mixtures of metals were explored to provide a great number of examples of this type of system. There are hundreds of both compounds composed of group 14 elements and group 15 elements, plus dozens of others beyond those groups, all spanning a variety of different geometries. Corbett has contributed improvements to the crystallization of Zintl ions by demonstrating the use of chelating ligands, such as cryptands, as cation sequestering agents. More recently, Zintl phase and ion reactivity in more complex systems, with organic ligands or transition metals, have been investigated, as well as their use in practical applications, such as for catalytic purposes or in materials science. Zintl phases Zintl phases are intermetallic compounds that have a pronounced ionic bonding character. They are made up of a polyanionic substructure and group 1 or 2 counter ions, and their structure can be understood by a formal electron transfer from the electropositive element to the more electronegative element in their composition. Thus, the valence electron concentration (VEC) of the anionic element is increased, and it formally moves to the right in its row of the periodic table. Generally the anion does not reach an octet, so to
Zintl phase
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The periodic table of mathematical shapes is popular name given to a project to classify Fano varieties. The project was thought up by Professor Alessio Corti, from the Department of Mathematics at Imperial College London. It aims to categorise all three-, four- and five-dimensional shapes into a single table, analogous to the periodic table of chemical elements. It is meant to hold the equations that describe each shape and, through this, mathematicians and other scientists expect to develop a better understanding of the shapes’ geometric properties and relations. The project has already won the Philip Leverhulme Prize—worth £70,000—from the Leverhulme Trust, and in 2019 a European Research Council grant. While it is estimated that 500 million shapes can be defined algebraically in four dimensions, they may be decomposable (in the sense of the minimal model program) into as few as a few thousand "building blocks". See also List of complex and algebraic surfaces List of surfaces Lists of shapes List of mathematical shapes List of two-dimensional geometric shapes References External links Fano Varieties and Extremal Laurent Polynomials A collaborative research blog for the project. 'Periodic Table of Shapes' to Give a New Dimension to Math Atoms ripple in the periodic table of shapes Nature's building blocks brought to life Databases of quantum periods for Fano manifolds by Tom Coates and Alexander M. Kasprzyk Geometric shapes
Periodic table of shapes
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These isotope tables show all of the known isotopes of the chemical elements, arranged with increasing atomic number from left to right and increasing neutron number from top to bottom. Half lives are indicated by the color of each isotope's cell (see color chart in each section). Colored borders indicate half lives of the most stable nuclear isomer states. The data for these tables came from Brookhaven National Laboratory which has an interactive Table of Nuclides with data on ~3000 nuclides. Recent discoveries are sourced from M. Thoennessen's "Discovery of Nuclides Project" website . Isotopes for elements 0-29 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 30-59 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 60-89 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 90-118 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table External links Interactive Chart of Nuclides (Brookhaven National Laboratory) The Lund/LBNL Nuclear Data Search An isotope table with clickable information on every isotope and its decay routes is available at chemlab.pc.maricopa.edu An example of free Universal Nuclide Chart with decay information for over 3000 nuclides is available at Nucleonica.net. app for mobiles: Android or Apple - for PC use The Live Chart of Nuclides - IAEA Links to other charts of nuclides, including printed posters and journal articles, is available at nds.iaea.org. Tables of nuclides
Table of nuclides (segmented, wide)
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Memoware is a term originally coined in 1996 for data formatted for the Memopad application that was shipped with the original U.S. Robotics Pilot (now Palm) Personal Digital Assistant. The MemoWare website was started shortly afterward by Craig Froehle as a central repository for memoware, and now hosts thousands of documents (in various formats) for Palm OS devices and other handhelds. History The idea and the name came out of discussions on a Pilot-related email list (managed by Tracy R. Reed) in August and September 1996. The term was probably coined by Bill Raynor in an email of 30 Aug 1996, wherein he said: "I've made up a number of tables of statistical distributions ... for my own use. Is this a category that the list would like to see circulated? (call it memoware?)". He emailed this list on 7 September in an email with the subject line: Pilot: Memoware - statistical tables". On 12 September Jeffrey Macko wrote, on the subject of maintaining grocery lists on the Pilot: "I'm half tempted to start a pilot site for small useful databases." and Craig Froehle replied "I think that if everybody mailed you their lists of useful stuff, and you put them on a web page for us to copy-n-paste into the Pilot desktop PIM, that'd be real handy." The following day, a list-member called QuZaX reported that he was working on early content, including weights and measures, the Periodic table, and other elements. On 14 September QuZax reminded the list that the data tables would not be a program. "They will just be in memoformat. I just used tabs to make them easy to read and so they would line up nicely." On the following Tuesday (17 September), Froehle announced that he had posted some memos on his website on a server at the University of Cincinnati. He wrote: "Due to overwhelming demand (approx. 15 requests an hour all yesterday and today, so far), I've put up these memos on my website. If you've no access to the WWW or for some other reason, just can't figure out how to get this text onto your PC, email me direct and I'll mail them to you. If you want me to, I can put up your useful Memowarez(tm) if you email them to me. Maybe this can start to be a big repository of pre-formatted Pilot data..." Many list-members created Memoware over the next days and months, notably Mark Carden (periodic table of elements, international data), Jon Flemming (US Presidents), John Komdat (US States), Bill Raynor (statistical tables, Quake video game cheats), Bradley Batt (sports results), and others. Craig's "memoware" database grew rapidly, as he predicted, moving to the domain www.memoware.com in July 1997 and reaching 300 documents a few months later. He then continued adding documents and e-books, mostly donated by users, in various new mobile formats developed for Palm OS and other handhelds, including Doc and TomeRaider. By late 2001, MemoWare was serving over half a million individual users
Memoware
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The isotope tables given below show all of the known isotopes of the chemical elements, arranged with increasing atomic number from left to right and increasing neutron number from top to bottom. Half lives are indicated by the color of each isotope's cell (see color chart in each section). Colored borders indicate half lives of the most stable nuclear isomer states. The data for these tables came from Brookhaven National Laboratory which has an interactive Table of Nuclides with data on ~3000 nuclides. Isotopes for elements 0-14 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 15-29 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 30-44 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 45-59 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 60-74 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 75-89 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 90-104 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table Isotopes for elements 105-118 ← Previous | Next →Go to Unitized table (all elements)Go to Periodic table External links Interactive Chart of Nuclides (Brookhaven National Laboratory) The Lund/LBNL Nuclear Data Search An isotope table with clickable information on every isotope and its decay routes is available at chemlab.pc.maricopa.edu An example of free Universal Nuclide Chart with decay information for over 3000 nuclides is available at Nucleonica.net. The LIVEChart of Nuclides - IAEA Links to other charts of nuclides, including printed posters and journal articles, is available at nds.iaea.org. Tables of nuclides
Table of nuclides (segmented, narrow)
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The atomic radius of a chemical element is the distance from the center of the nucleus to the outermost shell of an electron. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Depending on the definition, the term may apply only to isolated atoms, or also to atoms in condensed matter, covalently bound in molecules, or in ionized and excited states; and its value may be obtained through experimental measurements, or computed from theoretical models. Under some definitions, the value of the radius may depend on the atom's state and context. Atomic radii vary in a predictable and explicable manner across the periodic table. For instance, the radii generally decrease rightward along each period (row) of the table, from the alkali metals to the noble gases; and increase down each group (column). The radius increases sharply between the noble gas at the end of each period and the alkali metal at the beginning of the next period. These trends of the atomic radii (and of various other chemical and physical properties of the elements) can be explained by the electron shell theory of the atom; they provided important evidence for the development and confirmation of quantum theory. Atomic radius Note: All measurements given are in picometers (pm). For more recent data on covalent radii see Covalent radius. Just as atomic units are given in terms of the atomic mass unit (approximately the proton mass), the physically appropriate unit of length here is the Bohr radius, which is the radius of a hydrogen atom. The Bohr radius is consequently known as the "atomic unit of length". It is often denoted by a0 and is approximately 53 pm. Hence, the values of atomic radii given here in picometers can be converted to atomic units by dividing by 53, to the level of accuracy of the data given in this table. See also Atomic radius Covalent radius (Single-, double- and triple-bond radii, up to the superheavy elements.) Ionic radius Notes Difference between empirical and experimental data: Empirical data basically means, "originating in or based on observation or experience" or "relying on experience or observation alone often without due regard for system and theory data". It basically means that you measured it through physical observation, and a lot of experiments generating the same results. Although, note that the values are not calculated by a formula. However, often the empirical results then become an equation of estimation. Experimental data on the other hand are only based on theories. Such theoretical predictions are useful when there are no ways of measuring radii experimentally, if you want to predict the radius of an element that hasn't been discovered yet, or it has too short of a half-life. The radius of an atom is not a uniquely defined property and depends on the definition. Data derived from other sources with different assumptions cannot be compared. † to an accuracy of about 5 pm (b) 12 coordinate (c) gallium has an
Atomic radii of the elements (data page)
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The periodic table is a tabular arrangement of the chemical elements. Periodic table may also refer to: The Periodic Table (short story collection), by Primo Levi, 1975 The Periodic Table (Basher book), a 2007 children's science book Periodic table (crystal structure), a variant of the periodic table of chemical elements Periodic table (electron configurations), a variant of the periodic table of chemical elements See also Alternative periodic tables Extended periodic table Periodic table of topological invariants
Periodic table (disambiguation)
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Antonius Johannes van den Broek (4 May 1870, Zoetermeer – 25 October 1926, Bilthoven) was a Dutch amateur physicist notable for being the first who realized that the number of an element in the periodic table (now called atomic number) corresponds to the charge of its atomic nucleus. This hypothesis was published in 1911 and inspired the experimental work of Henry Moseley, who found good experimental evidence for it by 1913. Life Van den Broek was the son of a civil law notary and trained to be a lawyer himself. He studied at Leiden University and at the Sorbonne in Paris, obtaining a degree in 1895 in Leiden. From 1895 to 1900 he held a lawyers office in The Hague until 1900, after which he studied mathematical economy in Vienna and Berlin. However, from 1903 on, his main interest was physics. Much of the time between 1903 and 1911 he lived in France and Germany. Most of his papers he wrote between 1913 and 1916 while living in Gorssel. He married Elisabeth Margaretha Mauve in 1906, with whom he had five children. Major contribution to science The idea of the direct correlation of the charge of the atom nucleus and the periodic table was contained in his paper published in Nature on 20 July 1911, just one month after Rutherford published the results of his experiments that showed the existence of a small charged nucleus in an atom (see Rutherford model). However, Rutherford's original paper noted only that the charge on the nucleus was large, on the order of about half of the atomic weight of the atom, in whole number units of hydrogen mass. Rutherford on this basis made the tentative suggestion that atomic nuclei are composed of numbers of helium nuclei, each with a charge corresponding to half of its atomic weight. This would make the nuclear charge nearly equal to atomic number in smaller atoms, with some deviation from this rule for the largest atoms, such as gold. For example, Rutherford found the charge on gold to be about 100 units and thought perhaps that it might be exactly 98 (which would be close to half its atomic weight). But gold's place in the periodic table (and thus its atomic number) was known to be 79. Thus Rutherford did not make the proposal that the number of charges in the nucleus of an atom might be exactly equal to its place on the periodic table (atomic number). This is the idea put forward by Van den Broek. The number of the place of an element in the periodic table (or atomic number) at that time was not thought by most physicists to be a physical property. It was not until the work of Henry Moseley working with the Bohr model of the atom with the explicit idea of testing Van den Broek's theory, that it was realized that atomic number was indeed a purely physical property (the charge of the nucleus) which could be measured, and that
Antonius van den Broek
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The Periodic Table: Elements with Style is a 2007 children's science book created by Simon Basher and written by Adrian Dingle. It is the first book in Basher's science series, which includes Physics: Why Matter Matters!, Biology: Life As We Know It, Astronomy: Out of this World!, Rocks and Minerals: A Gem of a Book, and Planet Earth: What Planet Are You On?, each of which is 128 pages long. The book is arranged in eleven chapters plus an introduction, and includes a poster in the back of the book. Each chapter is on a different group of the periodic table (hydrogen, the alkali metals, the alkaline earth metals, the transition metals, the boron elements, the carbon elements, the nitrogen elements, the oxygen elements, the halogen elements, the noble gases, the lanthanides and actinides, and the transactinides). For every type of then known atom, Basher has created a "manga-esque" cartoon, and for many types of atoms, Dingle, a high-school chemistry teacher who also developed an award-winning chemistry website has written a couple paragraphs of facts to go with the cartoon. Dingle, who says that "[s]cience is a serious business", wanted in writing the book "to get people engaged is to make it accessible while still presenting hard facts and knowledge," while Basher was concerned that the book's design be "sharp and focused" in order to "connect with today's visually advanced young audience." Critical response Publishers Weekly said that the book was a "lively introduction to the chart that has been the bane of many a chemistry student", and in a review in New Scientist, Vivienne Greig called The Periodic Table "an engrossing read and an ideal way to painlessly impart a great deal of science history to seen-it-all-before teenagers." A review on the Royal Society of Chemistry website had some minor reservations about the book, but said it was "endearing" and succeeded in making learning chemistry easier and more fun. The Periodic Table: Elements with Style has also been reviewed in the Bulletin of the Center for Children's Books and the Journal of Chemical Education. References External links Simon Basher's website Adrian Dingle's award-winning chemistry website Kingfisher - publisher's website The Periodic Table - publisher's book page Basher books website Periodic table in popular culture 2007 non-fiction books Chemistry books 2007 children's books Children's books about science Children's non-fiction books
The Periodic Table (Basher book)
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A period on the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor. Arranged this way, elements in the same group (column) have similar chemical and physical properties, reflecting the periodic law. For example, the halogens lie in the second-to-last group (group 17) and share similar properties, such as high reactivity and the tendency to gain one electron to arrive at a noble-gas electronic configuration. , a total of 118 elements have been discovered and confirmed. Modern quantum mechanics explains these periodic trends in properties in terms of electron shells. As atomic number increases, shells fill with electrons in approximately the order shown in the ordering rule diagram. The filling of each shell corresponds to a row in the table. In the s-block and p-block of the periodic table, elements within the same period generally do not exhibit trends and similarities in properties (vertical trends down groups are more significant). However, in the d-block, trends across periods become significant, and in the f-block elements show a high degree of similarity across periods. Periods There are currently seven complete periods in the periodic table, comprising the 118 known elements. Any new elements will be placed into an eighth period; see extended periodic table. The elements are colour-coded below by their block: red for the s-block, yellow for the p-block, blue for the d-block, and green for the f-block. Period 1 The first period contains fewer elements than any other, with only two, hydrogen and helium. They therefore do not follow the octet rule, but rather a duplet rule. Chemically, helium behaves like a noble gas, and thus is taken to be part of the group 18 elements. However, in terms of its nuclear structure it belongs to the s-block, and is therefore sometimes classified as a group 2 element, or simultaneously both 2 and 18. Hydrogen readily loses and gains an electron, and so behaves chemically as both a group 1 and a group 17 element. Hydrogen (H) is the most abundant of the chemical elements, constituting roughly 75% of the universe's elemental mass. Ionized hydrogen is just a proton. Stars in the main sequence are mainly composed of hydrogen in its plasma state. Elemental hydrogen is relatively rare on Earth, and is industrially produced from hydrocarbons such as methane. Hydrogen can form compounds with most elements and is present in water and most organic compounds. Helium (He) exists only as a gas except in extreme conditions. It is the second-lightest element and is the second-most abundant in the universe. Most helium was formed during the Big Bang, but new helium is created through nuclear fusion of hydrogen in stars. On Earth, helium is relatively rare, only occurring as a byproduct of the natural decay of some radioactive elements. Such 'radiogenic' helium is trapped within natural gas in concentrations of up to seven
Period (periodic table)
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Lawrencium is a synthetic chemical element; it has symbol Lr (formerly Lw) and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements. A radioactive metal, lawrencium is the eleventh transuranic element and the last member of the actinide series. Like all elements with atomic number over 100, lawrencium can only be produced in particle accelerators by bombarding lighter elements with charged particles. Fourteen isotopes of lawrencium are currently known; the most stable is 266Lr with half-life 11 hours, but the shorter-lived 260Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale. Chemistry experiments confirm that lawrencium behaves as a heavier homolog to lutetium in the periodic table, and is a trivalent element. It thus could also be classified as the first of the 7th-period transition metals. Its electron configuration is anomalous for its position in the periodic table, having an s2p configuration instead of the s2d configuration of its homolog lutetium. However, this does not appear to affect lawrencium's chemistry. In the 1950s, 1960s, and 1970s, many claims of the synthesis of lawrencium of varying quality were made from laboratories in the Soviet Union and the United States. The priority of the discovery and therefore the name of the element was disputed between Soviet and American scientists. The International Union of Pure and Applied Chemistry (IUPAC) initially established lawrencium as the official name for the element and gave the American team credit for the discovery; this was reevaluated in 1997, giving both teams shared credit for the discovery but not changing the element's name. Introduction History In 1958, scientists at Lawrence Berkeley National Laboratory claimed the discovery of element 102, now called nobelium. At the same time, they also tried to synthesize element 103 by bombarding the same curium target used with nitrogen-14 ions. Eighteen tracks were noted, with decay energy around and half-life around 0.25 s; the Berkeley team noted that while the cause could be the production of an isotope of element 103, other possibilities could not be ruled out. While the data agrees reasonably with that later discovered for 257Lr (alpha decay energy 8.87 MeV, half-life 0.6 s), the evidence obtained in this experiment fell far short of the strength required to conclusively demonstrate synthesis of element 103. A follow-up on this experiment was not done, as the target was destroyed. Later, in 1960, the Lawrence Berkeley Laboratory attempted to synthesize the element by bombarding 252Cf with 10B and 11B. The results of this experiment were not conclusive. The first important work on element 103 was done at Berkeley by the nuclear-physics team of Albert Ghiorso, Torbjørn Sikkeland, Almon Larsh, Robert M. Latimer, and their co-workers on February 14, 1961. The first atoms of lawrencium were reportedly made by bombarding a three-milligram target consisting of three isotopes of californium with boron-10 and boron-11 nuclei from the Heavy Ion Linear Accelerator (HILAC).
Lawrencium
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Five elements may refer to: Philosophy Classical elements Godai (Japanese philosophy) Gogyo, five phase Japanese philosophy Wuxing (Chinese philosophy), ancient Chinese theory involving five 'phases', 'agents', or 'elements' Mahābhūta, the five elements in Indian philosophy Pancha Tattva (Vaishnavism) Science Boron, element 5 in the periodic table Group 5 element, elements in the fifth column of the periodic table Period 5 element, elements in the fifth row of the periodic table Music Five Elements, a band led by jazz musician Steve Coleman See also Element (disambiguation) Fifth Element (disambiguation)
Five elements
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Andreas von Antropoff (; 16 August 1878, Reval, Russian empire — 2 June 1956, Bonn) — Russian (Estonian-born) and German scientist-chemist, professor at the Bonn University and is known to have coined the term "neutronium" and developed a temporarily and widely used alternative periodic table of elements in 1926. Biography His father was Roman von Antropoff, a lawyer and owner of a manor house and his mother was Sophie Emilie von Antropoff. Antropoff had four brothers and one sister: Roman Andreas von Antropoff Elisabeth Molly von Antropoff Sergei von Antropoff Nikolai Alexander von Antropoff Karl Alexander von Antropoff From 1889 to 1892 Andreas von Antropoff attended the Domschule of the St Mary's Cathedral, Tallinn, in 1893 the Lajusschule and later the secondary school in Reval. He studied mechanical engineering at the Polytechnic School in Riga from 1897 to 1899 and chemistry from 1899 to 1904. From 1904 to 1907 he studied chemistry in Heidelberg, where he graduated as a Doctor of Science (Dr. phil. nat.). In 1907 and 1908 he worked as a researcher at the University College London under William Ramsay. From 1908 to 1915 he was assistant and associate professor and from 1911 to 1915 lecturer for inorganic chemistry at the Riga Polytechnic School. In 1911 he made his Magister degree at the Saint Petersburg State University and was department head at the Central Chamber for Measures and Weights in Saint Petersburg. In 1916 he was arrested on allegations of espionage in connection with World War I and imprisoned from July 1916 until March 1917 in Saint Petersburg. From September 1917 until January 1918 he served in the military. In 1918 he was again arrested for political reasons by Bolsheviks of the Petrograd Soviet. In 1918 Antropoff was appointed to the Technical College in Karlsruhe, from where he went to serve in Bonn as a full professor and department head for physical chemistry from 1924. Andreas von Antropoff married Erika Pauline Alice von Antropoff (born Erika Germanniga in Spremberg) on 11 December 1926. Antropoff became dean of the faculty of mathematics and natural sciences in Bonn University and a member of the Senate. An active national socialist, he was the first to hoist the swastika flag at the university in 1933. In 1944 he took over the management of the Agricultural Research Institute in Ebstorf, Uelzen county. As a result of his Nazi past, he was suspended from office in 1945 and retired in 1948. Antropoff's periodic table He first published his periodic table in the article "Eine neue Form des periodischen Systems der Elemente" in the Zeitschrift für angewandte Chemie in 1926. The periodic table is regularly numbered from 1 - Hydrogen to 118 - Oganesson, with "each number representing the number of protons stored within an atom's nucleus in a satisfying balance" compared to most other contemporary tables. In addition he placed the theoretical "Element zero" atop his periodic table and called it Neutronium. His periodic table was in widespread use in German schools until 1945
Andreas von Antropoff
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In chemistry and atomic physics, an electron shell may be thought of as an orbit that electrons follow around an atom's nucleus. The closest shell to the nucleus is called the "1 shell" (also called the "K shell"), followed by the "2 shell" (or "L shell"), then the "3 shell" (or "M shell"), and so on farther and farther from the nucleus. The shells correspond to the principal quantum numbers (n = 1, 2, 3, 4 ...) or are labeled alphabetically with the letters used in X-ray notation (K, L, M, ...). A useful guide when understanding electron shells in atoms is to note that each row on the conventional periodic table of elements represents an electron shell. Each shell can contain only a fixed number of electrons: the first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons. For an explanation of why electrons exist in these shells, see electron configuration. Each shell consists of one or more subshells, and each subshell consists of one or more atomic orbitals. History In 1913, Niels Bohr proposed a model of the atom, giving the arrangement of electrons in their sequential orbits. At that time, Bohr allowed the capacity of the inner orbit of the atom to increase to eight electrons as the atoms got larger, and "in the scheme given below the number of electrons in this [outer] ring is arbitrary put equal to the normal valency of the corresponding element". Using these and other constraints, he proposed configurations that are in accord with those now known only for the first six elements. "From the above we are led to the following possible scheme for the arrangement of the electrons in light atoms:" The shell terminology comes from Arnold Sommerfeld's modification of the 1913 Bohr model. During this period Bohr was working with Walther Kossel, whose papers in 1914 and in 1916 called the orbits "shells". Sommerfeld retained Bohr's planetary model, but added mildly elliptical orbits (characterized by additional quantum numbers and m) to explain the fine spectroscopic structure of some elements. The multiple electrons with the same principal quantum number (n) had close orbits that formed a "shell" of positive thickness instead of the circular orbit of Bohr's model which orbits called "rings" were described by a plane. The existence of electron shells was first observed experimentally in Charles Barkla's and Henry Moseley's X-ray absorption studies. Moseley's work did not directly concern the study of electron shells, because he was trying to prove that the periodic table was not arranged by weight, but by the charge of the protons in the nucleus. However, because the number of electrons in an electrically neutral atom equals the number of protons, this work was extremely important to Niels Bohr who mentioned
Electron shell
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Brady John Haran (born 18 June 1976) is an Australian-British independent filmmaker and video journalist who produces educational videos and documentary films for his YouTube channels, the most notable being Computerphile and Numberphile. Haran is also the co-host of the Hello Internet podcast along with fellow educational YouTuber CGP Grey. On 22 August 2017, Haran launched his second podcast, called The Unmade Podcast, and on 11 November 2018, he launched his third podcast, The Numberphile Podcast, based on his mathematics-centered channel of the same name. Reporter and filmmaker Brady Haran studied journalism for a year before being hired by The Adelaide Advertiser. In 2002, he moved from Australia to Nottingham, United Kingdom. In Nottingham, he worked for the BBC, began to work with film, and reported for East Midlands Today, BBC News Online and BBC radio stations. In 2007, Haran worked as a filmmaker-in-residence for Nottingham Science City, as part of an agreement between the BBC and the University of Nottingham. His "Test Tube" project started with the idea of producing a documentary about scientists and their research, but he decided to upload his raw footage to YouTube; from that point "Periodic Videos" and "Sixty Symbols" were developed. Haran then left the BBC to work full-time making YouTube videos. YouTube channels Following Test Tube, Haran decided to create new YouTube channels. In his first five years as an independent filmmaker he made over 1500 videos and in 2012, he was the producer, editor, and interviewer behind 12 YouTube channels. Haran frequently collaborates with well-known academics and professionals. Haran's videos are often in the format of a casual interview in which Haran and an expert discuss subjects relevant to their work. The Periodic Table of Videos Started in June 2008, Periodic Videos is a series of videos about chemical elements and the periodic table. Working with Professor Martyn Poliakoff, Haran's videos explaining chemistry and science for non-technical persons have received positive recognition. Together, they have made over 500 short videos that cover the elements and other chemistry-related topics. Their YouTube channel has had more than 159 million views. Also, Haran and Poliakoff authored an article in the Nature Chemistry journal and an essay on Science journal discussing the impact of The Periodic Table of Videos. Martyn Poliakoff received the Royal Society of Chemistry Nyholm Prize for Education in 2011 for work taking chemistry education to a wider audience; this included his work with Haran on The Periodic Table of Videos. Sixty Symbols Sixty Symbols is Haran's YouTube channel for physics and astronomy. The first video was released in April 2009, with the original run of videos focusing on commonly used physics notations. Since then, videos on topics such as the greenhouse effect, the age of the universe, and several on black holes have been released. Numberphile Started in October 2011, Numberphile features videos that explore educational topics from a variety of fields of mathematics. It is currently Haran's most subscribed channel. In the early days of the channel, each video focused
Brady Haran
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In chemistry, a diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods (first 20 elements) of the periodic table. These pairs (lithium (Li) and magnesium (Mg), beryllium (Be) and aluminium (Al), boron (B) and silicon (Si), etc.) exhibit similar properties; for example, boron and silicon are both semiconductors, forming halides that are hydrolysed in water and have acidic oxides. The organization of elements on the periodic table into horizontal rows and vertical columns makes certain relationships more apparent (periodic law). Moving rightward and descending the periodic table have opposite effects on atomic radii of isolated atoms. Moving rightward across the period decreases the atomic radii of atoms, while moving down the group will increase the atomic radii. Similarly, on moving rightward a period, the elements become progressively more covalent, less basic and more electronegative, whereas on moving down a group the elements become more ionic, more basic and less electronegative. Thus, on both descending a period and crossing a group by one element, the changes "cancel" each other out, and elements with similar properties which have similar chemistry are often found – the atomic radius, electronegativity, properties of compounds (and so forth) of the diagonal members are similar. It is found that the chemistry of a period 2 element often has similarities to the chemistry of the period 3 element one column to the right of it in the periodic table. Thus, the chemistry of Li has similarities to that of Mg, the chemistry of Be has similarities to that of Al, and the chemistry of B has similarities to that of Si. These are called diagonal relationships. (They are not as noticeable after B and Si.) The reasons for the existence of diagonal relationships are not fully understood, but charge density is a factor. For example, Li+ is a small cation with a +1 charge and Mg2+ is somewhat larger with a +2 charge, so the ionic potential of each of the two ions is roughly the same. It was revealed by an examination that the charge density of lithium is much closer to that of magnesium than to those of the other alkali metals. Using the Li–Mg pair (under room temperature and pressure): When combined with oxygen under standard conditions, Li and Mg form only normal oxides whereas Na forms peroxide and metals below Na, in addition, form superoxides. Li is the only group 1 element which forms a stable nitride, Li3N. Mg, as well as other group 2 elements, also form nitrides. Lithium carbonate, phosphate and fluoride are sparingly soluble in water. The corresponding group 2 salts are insoluble. (Think lattice and solvation energies). Both Li and Mg form covalent organometallic compounds. LiMe and MgMe2 (cf. Grignard reagents) are both valuable synthetic reagents. The other group 1 and group 2 analogues are ionic and extremely reactive (and hence difficult to manipulate). Chlorides of both Li and Mg are deliquescent (absorb moisture from surroundings) and soluble in alcohol
Diagonal relationship
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A period 4 element is one of the chemical elements in the fourth row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The fourth period contains 18 elements beginning with potassium and ending with krypton – one element for each of the eighteen groups. It sees the first appearance of d-block (which includes transition metals) in the table. Properties All 4th-period elements are stable, and many are extremely common in the Earth's crust and/or core; it is the last period with no unstable elements. Many transition metals in the period are very strong, and therefore common in industry, especially iron. Some are toxic, with all known vanadium compounds toxic, arsenic one of the most well-known poisons, and bromine a toxic liquid. Conversely, many elements are essential to human survival, such as calcium, the main component in bones. Atomic structure Progressing towards increase of atomic number, the Aufbau principle causes elements of the period to put electrons onto 4s, 3d, and 4p subshells, in that order. However, there are exceptions, such as chromium. The first twelve elements—K, Ca, and transition metals—have from 1 to 12 valence electrons respectively, which are placed on 4s and 3d. Twelve electrons over the electron configuration of argon reach the configuration of zinc, namely 3d10 4s2. After this element, the filled 3d subshell effectively withdraws from chemistry and the subsequent trend looks much like trends in the periods 2 and 3. The p-block elements of period 4 have their valence shell composed of 4s and 4p subshells of the fourth () shell and obey the octet rule. For quantum chemistry namely this period sees transition from the simplified electron shell paradigm to research of many differently-shaped subshells. The relative disposition of their energy levels is governed by the interplay of various physical effects. The period's s-block metals put their differentiating electrons onto 4s despite having vacancies among nominally lower states – a phenomenon unseen in lighter elements. Contrariwise, the six elements from gallium to krypton are the heaviest where all electron shells below the valence shell are filled completely. This is no longer possible in further periods due to the existence of f-subshells starting from . List of elements {| class="wikitable sortable" ! colspan="3" | Chemical element ! Block ! Electron configuration |- ! ! ! ! ! |- bgcolor="" || 19 || K || Potassium || s-block || [Ar] 4s1 |- bgcolor="" || 20 || Ca || Calcium || s-block || [Ar] 4s2 |- bgcolor="" || 21 || Sc || Scandium || d-block || [Ar] 3d1 4s2 |- bgcolor="" || 22 || Ti || Titanium || d-block || [Ar] 3d2 4s2 |- bgcolor="" || 23 || V || Vanadium || d-block || [Ar] 3d3 4s2
Period 4 element
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Element collecting is the hobby of collecting the chemical elements. Many element collectors simply enjoy finding peculiar uses of chemical elements. Others enjoy studying the properties of the elements, possibly engaging in amateur chemistry, and some simply collect elements for no practical reason. Some element collectors invest in elements, while some amateur chemists have amassed a large collection of elements—Oliver Sacks, for example. In recent years, the hobby has gained popularity with media attention brought by element collectors like Theodore Gray. Sagar Jamane describes element collecting as “more a discipline than a hobby.” “It’s a reminder of the enormous effort of all the beautiful minds behind the periodic table and element discovery,” he says, adding that it’s thrilling to see the elements that make up the universe at such close quarters. Acquiring elements Some collectors attempt to collect very high purity samples of each element. Others prefer to find the element in everyday use. Some are averse to collecting the element as a compound or alloy, while others find this acceptable. Collectors may isolate elements in their own homes. Hydrogen, for example, can be easily isolated via the electrolysis of water. In addition to the element samples, some element collectors also collect items connected with the element, such as manufactured goods containing the element, rocks and minerals with the element as a constituent or compounds of the element. Some manufacturers also sell coins made from pure elements, and density cubes made from the pure element can also be sourced on auction sites such as eBay. Some commercial retailers now cater to the element collecting community, even selling large quantities in sets, since purchasing elements from large chemical companies is frequently prohibited or uneconomical for individuals. There are a number of specialist element providers which retail to the public over the web, sell individual element samples in addition to full and partial element sets. Many also sell elements through auction sites, such as eBay. Established specialist providers include Nova Elements, RGB Elements, Smart Elements, SMT Metalle Wimmer, PEGUYS, Metallium, Collect the Periodic Table, Luciteria, and Onyxmet. Practical issues Collecting macroscopic samples of all the elements is problematic: some elements, such as mercury, beryllium, thallium, plutonium, and arsenic are toxic and so are difficult to find or their sale is restricted. Others are rare in commerce, and thus hard to buy or expensive: scandium, lutetium, and thulium. Some, such as caesium, white phosphorus, and fluorine, are too reactive and have restrictions on their shipping; others, such as gallium, react corrosively and very fast with aluminium, so cannot be shipped by air. Some, such as phosphorus and iodine, are controlled due to use in clandestine chemistry. Others, like radon and astatine, are radioactive and have half-lives too short for practical collection in addition to their radioactive hazards. Usually only the stable elements from hydrogen to bismuth (except the radioactive technetium and promethium) are collected, with the exceptions of the extremely long-lived thorium and uranium. It is possible to source other radioactive elements, such
Element collecting
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A lyre arm is an element of design in furniture, architecture and the decorative arts, wherein a shape is employed to emulate the geometry of a lyre; the original design of this element is from the Classical Greek period, simply reflecting the stylistic design of the musical instrument. One of the earliest uses extant of the lyre design in the Christian era is a 6th-century AD gravestone with lyre design in double volute form. In a furniture context, the design is often associated with a scrolling effect of the arms of a chair or sofa. The lyre arm design arises in many periods of furniture, including Neoclassical schools and in particular the American Federal Period and the Victorian era. Well known designers who employed this stylistic element include the noted New York City furniture designer Duncan Phyfe. The term lyre chair is a closely associated design element also originating in motif from the Greek Classical period and appearing often in chair backs starting circa 1700 AD. In the lyre chair, the splat features a pair of single lyre scrolls with bilateral symmetry. This particular splat chair back was a favourite motif employed by the well known English furniture designer Thomas Sheraton. Sometimes a chair of this design is called a lyre back chair. In musical apparatus Not surprisingly the lyre motif has been used through history as an element of music stand and other musical appurtenance design. Perhaps most commonly the lyre design has been used for centuries as the backing of sheet music stands. As an example of the lyre design in other musical furniture, one highly ornate piano described in the 1902 catalog of the collection of the New York Metropolitan Museum of Art was depicted as: "having in the centre a lyre supporting the pedals". Other use of the lyre design Beyond the use of the lyre design in chairs, this motif is common in other decorative applications for furniture and other contents' accessories. In prehistoric Celtic design, the lyre is present in a number of works including a well preserved scabbard found in Antrim, Northern Ireland and now preserved in the Ulster Museum; this artifact has a bilaterally symmetric double lyre design. For example, in the Empire Period the lyre was commonly applied to mirrors, especially in the American Federal Period. In London in the late 18th century, Thomas Sheraton illustrated the lyre design for use in table supports. Another example of lyre supports in a table design is illustrated in History Of Furniture: Ancient to 19th Century, showing a small ebony table. Lockwood also documents that Sheraton enjoyed using a painted form of the lyre on furniture elements as decoration. Lockwood further illustrates a lyre supported games table from circa 1820 believed to have been produced by Duncan Phyfe. In fiction Numerous references exist to the lyre arm or lyre chair in fictional literature, the lyre design being associated with historical splendour and opulent living circumstances. In the noted artist Honoré Daumier's work Emportez donc
Lyre arm
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Unbiunium, also known as eka-actinium or element 121, is a hypothetical chemical element; it has symbol Ubu and atomic number 121. Unbiunium and Ubu are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be the first of the superactinides, and the third element in the eighth period. It has attracted attention because of some predictions that it may be in the island of stability. It is also likely to be the first of a new g-block of elements. Unbiunium has not yet been synthesized. It is expected to be one of the last few reachable elements with current technology; the limit could be anywhere between element 120 and 124. It will also likely be far more difficult to synthesize than the elements known so far up to 118, and still more difficult than elements 119 and 120. The teams at RIKEN in Japan and at the JINR in Dubna, Russia have indicated plans to attempt the synthesis of element 121 in the future after they attempt elements 119 and 120. The position of unbiunium in the periodic table suggests that it would have similar properties to lanthanum and actinium; however, relativistic effects may cause some of its properties to differ from those expected from a straight application of periodic trends. For example, unbiunium is expected to have a s2p valence electron configuration, instead of the s2d of lanthanum and actinium or the s2g expected from the Madelung rule, but this is not predicted to affect its chemistry much. It would on the other hand significantly lower its first ionization energy beyond what would be expected from periodic trends. Introduction History Fusion reactions producing superheavy elements can be divided into "hot" and "cold" fusion, depending on the excitation energy of the compound nucleus produced. In hot fusion reactions, very light, high-energy projectiles are accelerated toward very heavy targets (actinides), giving rise to compound nuclei at high excitation energies (~40–50 MeV) that may fission or evaporate several (3 to 5) neutrons. In cold fusion reactions (which use heavier projectiles, typically from the fourth period, and lighter targets, usually lead and bismuth), the fused nuclei produced have a relatively low excitation energy (~10–20 MeV), which decreases the probability that these products will undergo fission reactions. As the fused nuclei cool to the ground state, they require emission of only one or two neutrons. However, hot fusion reactions tend to produce more neutron-rich products because the actinides have the highest neutron-to-proton ratios of any element that can presently be made in macroscopic quantities; it is currently the only method to produce the superheavy elements from flerovium (element 114) onward. Attempts to synthesize elements 119 and 120 push the limits of current technology, due to the decreasing cross sections of the production reactions and their probably short half-lives, expected to be on the order of microseconds. Heavier elements,
Unbiunium
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The Commission on Isotopic Abundances and Atomic Weights (CIAAW) is an international scientific committee of the International Union of Pure and Applied Chemistry (IUPAC) under its Division of Inorganic Chemistry. Since 1899, it is entrusted with periodic critical evaluation of atomic weights of chemical elements and other cognate data, such as the isotopic composition of elements. The biennial CIAAW Standard Atomic Weights are accepted as the authoritative source in science and appear worldwide on the periodic table wall charts. The use of CIAAW Standard Atomic Weights is also required legally, for example, in calculation of calorific value of natural gas (ISO 6976:1995), or in gravimetric preparation of primary reference standards in gas analysis (ISO 6142:2006). In addition, until 2019 the definition of kelvin, the SI unit for thermodynamic temperature, made direct reference to the isotopic composition of oxygen and hydrogen as recommended by CIAAW. The latest CIAAW report was published in May 2022. Establishment Although the atomic weight had taken on the concept of a constant of nature like the speed of light, the lack of agreement on accepted values created difficulties in trade. Quantities measured by chemical analysis were not being translated into weights in the same way by all parties and standardization became an urgent matter. With so many different values being reported, the American Chemical Society (ACS), in 1892, appointed a permanent committee to report on a standard table of atomic weights for acceptance by the Society. Clarke, who was then the chief chemist for the U.S. Geological Survey, was appointed a committee of one to provide the report. He presented the first report at the 1893 annual meeting and published it in January 1894. In 1897, the German Society of Chemistry, following a proposal by Hermann Emil Fischer, appointed a three-person working committee to report on atomic weights. The committee consisted of Chairman Prof. Hans H. Landolt (Berlin University), Prof. Wilhelm Ostwald (University of Leipzig), and Prof. Karl Seubert (University of Hanover). This committee published its first report in 1898, in which the committee suggested the desirability of an international committee on atomic weights. On 30 March 1899 Landolt, Ostwald and Seubert issued an invitation to other national scientific organizations to appoint delegates to the International Committee on Atomic Weights. Fifty-eight members were appointed to the Great International Committee on Atomic Weights, including Frank W. Clarke. The large committee conducted its business by correspondence to Landolt which created difficulties and delays associated with correspondence among fifty-eight members. As a result, on 15 December 1899, the German committee asked the International members to select a small committee of three to four members. In 1902, Prof. Frank W. Clarke (USA), Prof. Karl Seubert (Germany), and Prof. Thomas Edward Thorpe (UK) were elected, and the International Committee on Atomic Weights published its inaugural report in 1903 under the chairmanship of Prof. Clarke. Function Since 1899, the Commission periodically and critically evaluates the published scientific literature and produces the Table of Standard Atomic Weights. In recent times, the Table of
Commission on Isotopic Abundances and Atomic Weights