Elementymology & Elements Multidict Introduction Periodic Table Elements Languages Indexes Specials Contact Development of the chemical symbols and the Periodic Table Lavoisier - Dalton - Berzelius - Менделеев (Mendeleev) - Moseley by Peter van der Krogt Lavoisier 1789 - 33 elements Antoine Lavoisier (1743-1794) introduced the system of chemical nomenclature. His Traité Élémentaire de Chimie (1789) was the first modern chemical textbook, and presented a unified view of new theories of chemistry. In addition, it contained a list of 33 elements, or substances that could not be broken down further. His list also included light (lumière) and caloric (calorique), which he believed to be material substances. Lavoisier himself grouped them into four categories on the basis of their chemical properties: Simple substances belonging to all the kingdoms of nature, which may be considered as the elements of bodies (gases), Oxydable and Acidifiable simple Substances not Metallic (nonmetals), Oxydable and Acidifiable simple Metallic Bodies (metals), Salifiable simple Earthy Substances (earths). In the first category he listed substances that we now know as oxides but which at the time had defeated all attempts at separation. Lavoisiers table of simple substances Gases New names (French) Old names (English translation) Lumière Light Calorique Heat Principle of heat Igneous fluid Fire Matter of fire and of heat Oxygène Dephlogisticated air Empyreal air Vital air Base of vital air Azote Phlogisticated gas Mephitis Base of mephitis Hydrogène Inflammable air or gas Base of inflammable air Metals New names (French) Old names (English translation) Antimoine Antimony Argent Silver Arsenic Arsenic Bismuth Bismuth Cobolt Cobalt Cuivre Copper Étain Tin Fer Iron Manganèse Manganese Mercure Mercury Molybdène Molybdena Nickel Nickel Or Gold Platine Platina Plomb Lead Tungstène Tungsten Zinc Zinc Nonmetals New names (French) Old names (English translation) Soufre Sulphur Phosphore Phosphorus Carbone Pure charcoal Radical muriatique Unknown Radical fluorique Unknown Radical boracique Unknown Earths New names (French) Old names (English translation) Chaux Chalk, calcareous earth Magnésie Magnesia, base of Epsom salt Baryte Barote, or heavy earth Alumine Clay, earth of alum, base of alum Silice Siliceous earth, vitrifiable earth Further reading: Antoine Lavoisier (1743-1794) from Elements of Chemistry (on-line). From Alchemy to Chemistry: Five Hundred Years of Rare and Interesting Books (on-line). Dalton 1808 - 36 elements John Dalton (1766-1844) was an English meteorologist who switched to chemistry when he saw the applications for chemistry of his ideas about the atmosphere. He proposed the Atomic Theory in 1803 which stated that all matter was composed of small indivisible particles termed atoms, atoms of a given element possess unique characteristics and weight, and three types of atoms exist: simple (elements), compound (simple molecules), and complex (complex molecules). Daltons theory was presented in New System of Chemical Philosophy (1808-1827). Since the old achemical symbols were not fit to use in his theory, he proposed a new set of standard symbols for the chemical elements in the first volume of his New System. A few of his symbols are here above, to the right the page from the New System, also the background image of this website is an illustrations of Daltons symbols. Daltons symbols were not much better than previous examples, as there was nothing about them which made it easy to memorise them. However, Daltons symbols did have some benefits: each symbol represented one atom and the formula of a compound was made up of the symbols of its elements, it showed how many of these atoms were present in the molecule. O Oxygen H Hydrogen N Nitrogen C Carbon S Sulphur P Phosphorus Au Gold Pt Platinum Ag Silver Hg Mercury Cu Copper Fe Iron Ni Nickel Sn Tin Pb Lead Zn Zinc Bi Bismuth Sb Antimony As Arsenic Co Cobalt Mn Manganese U Uranium W Tungsten Ti Titanium Ce Cerium K Potassium Na Sodium Ca Calcium Mg Magnesium Ba Barium Sr Strontium Al Aluminium Si Silicon Y Yttrium Be Beryllium Zr Zirconium A few years later Daltons system was superseded with the chemical symbols and formulae by Jöns Berzelius, which are still used today. Further reading: John Dalton (1766-1844): The Father of the Chemical Atomic Theory (on-line). Berzelius 1813-14 - 47 elements As we see in the complete list of Daltin symbols, the symbol for newly discovered elements was a letter or two letters in a circle. It is therefor quite logical that a few years later, in Sweden, Berzelius suggested just using letters, argumenting those are easier to write and print. The chemical signs ought to be letters, for the greater facility of writing, and not to disfigure a printed book. Though this last circumstance may not appear of any great importance, it ought to be avoided whenever it can be done. I shall take, therefore, for the chemical sign, the initial letter of the Latin name of each elementary substance: but as several have the same initial letter, I shall distinguish them in the following manner:-- In the class which I call metalloids, I shall employ the initial letter only, even when this letter is common to the metalloid and some metal. In the class of metals, I shall distinguish those that have the same initials with another metal, or a metalloid, by writing the first two letters of the word. If the first two letters be common to two metals, I shall, in that case, add to the initial letter the first consonant which they have not in common: for example, S = sulphur, Si = silicium, St = stibium (antimony), Sn = stannum (tin), C = carbonicum, Co = cobaltum (cobalt), Cu = cuprum (copper), O = oxygen, Os = osmium, &c. What he does not write here, is that the basis for his symbols is the Latin name of the element. With some modifications, Berzeliuss symbols are the ones that we use today. In the table below the names (in alphabetical order of their Latin name) and symbols are reproduced from Berzeliuss article, with modifications indicated. Element Berz. present Aluminium Al Argentum (Silver) Ag Arsenic As Aurum (Gold) Au Barium Ba Bismuth Bi Boron B Calcium Ca Carbon C Cerium Ce Chromium Ch Cr Cobalt Co Columbium Cl (Cb) Nb Cuprum (Copper) Cu Ferrum (Iron) Fe Fluoric Radicle F Element Berz. present Glucinum Gl Be Hydrargyrum (Mercury) Hg (Hy) Hg Hydrogenium H Iridium I Ir Magnesium Ms Mg Manganese Ma (Mn) Mn Molybdenum Mo Muriatic Radicle (Chlorine) M Cl Nickel Ni Nitric Radicle N Osmium Os Oxygenium O Palladium Pa Pd Phosphorus P Platinum Pt Plumbum (Lead) Pb (P) Pb Element Berz. present Potassium Po K Rhodium Rh (R) Rh Silicium Si Sodium So Na Stibium (Antimony)* Sb (St) Sb Strontium Sr Sulphur S Tellurium Te Tin Sn (St) Sn Titanium Ti Tungsten Tn (W) W Uranium U Yttrium Y Zinc Zn Zirconium Zr The symbols used in his lengthy paper are not entirely consistent throughout. Between brackets are the symbols used in the text. Further reading: Jöns Jacob Berzelius, Essay on the Cause of Chemical Proportions, and on Some Circumstances Relating to Them: Together with a Short and Easy Method of Expressing Them; chapter III. On the Chemical Signs, and the Method of Employing them to Express Chemical Proportions. (on-line). Periodical system In the first decade of the nineteenth century, no less than fourteen new elements were added to the list. Davy alone had isolated no fewer than six by means of electrolysis. The haul in succeeding decades was not quite as rich, but the number of elements continued to mount. Berzelius discovered four more elements: Selenium, Silicon, Zirconium, and Thorium. By 1830, fifty-five different elements were recognized. The number became too great for the comfort of chemists. The elements varied widely in properties and there seemed little order about them. Why were there so many? And how many more yet remained to be found? It was tempting to search for order in the list of elements already known. Perhaps in this manner some reason for the number of elements might be found and some way of accounting for the variation of properties that existed. Several proposals were made to arrange the elements in a table: 1829, Johann Wolfgang Döbereiner (1780-1849), Model of Triads. In 1829, he noted that the newly discovered element Bromine seemed just halfway in its properties between Chlorine and Iodine. He found two other groups of three elements with the same characteristics (Ca, Sr, and Ba; and S, Se, and Te). He called these groups triads and searched unsuccessfully for others. (note). 1859, Jean-Baptiste Dumas (1800-1884) extended Döbereiners triads into families of elements in fours (F, Cl, Br, and I; Mg, Ca, Sr, and Ba). 1863, Alexandre-Émile Béguyer de Chancourtois (1820-1886), Vis Tellurique (Telluric Screw). He created a list of the elements, arranged by increasing atomic weight. The list was wrapped around a cylinder so that several sets of similar elements lined up, creating the first geometric representation of the periodic law. 1864, William Odling (1829-1921) was intrigued by atomic weights and the periodic occurrence of chemical properties. He proposed repeating units of 7. The table of elements he drew up bears a striking resemblance to Mendeleev’s first table. 1864, John Alexander Reina Newlands (1837-1898), Law of Octaves. Extending the work of Döbereiner and Dumas, he arranged the known elements by increasing atomic mass along horizontal rows seven elements long. He stated that the eighth element would have similar properties to the first from the series. His work failed after Ca in predicting a consistent trend. 1H 7Li 9Be 11B 12C 14N 16O 19F 23Na 24Mg 27Al 28Si 31P 32S 35Cl 39K 40Ca 52Cr 48Ti 55Mn 56Fe 1869-71, Дмитрий Иванович Менделеев (see below). 1870, Lothar Meyer (1830-1895). He independently developed a periodic table based on atomic masses. He found that if the atomic volumes of the elements were plotted against their atomic weight, a series of peaks were produced. The peaks were formed by the alkali metals Sodium, Potassium, Rubidium, and Cesium. Each fall and rise to a peak, corresponded to a period like the waves. In each period a number of physical properties other than atomic volume also fell and rose, such as valence and melting point. Meyer was the first scientist to introduce the concept of valence as a periodic property (note). 1913, Moseley (see below). Менделеев (Mendeleev) 1869 - 63 elements Дмитрий Иванович Менделеев (Dmitrij Ivanovič Mendeleev) (1834-1907) (how to spell his name? click here) had in 1869 assembled detailed descriptions of more than 60 elements and, on 6 March 1869 a formal presentation was made to the Russian Chemical Society entitled The Dependence Between the Properties of the Atomic Weights of the Elements. Unfortunately, Mendeleev was ill and the presentation was given by his colleague Professor Menshutken. The same year, a summary of this paper was published in German in the Zeitschrift für Chemie (note). There were eight points to his presentation: The elements, if arranged according to their atomic weights, exhibit an apparent periodicity of properties. Elements which are similar as regards their chemical properties have atomic weights which are either of nearly the same value (Pt, Ir, Os) or which increase regularly (K, Rb, Cs). The arrangement in the order of their atomic weights corresponds to the valencies of the elements and, to some extent, to their distinctive chemical properties, e.g. Li, Be, Ba, C, N, O, F. The elements which are the most widely diffused in nature have small atomic weights. The magnitude of the atomic weight determines the character of the element, just as the magnitude of the molecule determines the character of a compound body. The discovery of many as yet unknown elements is expected, for example, elements analogous to Si and Al, whose atomic weight would be between 65 and 75. Some atomic weights are expected to be corrected, for example, Te can not have the atomic weight 128, but it must lie between 123 and 126. From this table new analogies between elements can be foretold. So seems Bo (?) (in the table the symbol is Ur) analogous to B and Al, which, as is known, by experiments is proven. He published his periodic table in The Principles of Chemistry (St. Petersburg, 1868-70). Ti = 50 Zr = 90 ? = 180 V = 51 Nb = 94 Ta = 182 Cr = 52 Mo = 96 W = 186 Mn = 55 Rh = 104,4 Pt = 197,4 Fe = 56 Ru = 104,4 Ir = 198 Ni= Co = 59 Pl = 106,6 Os = 199 H = 1 Cu = 63,4 Ag = 108 Hg = 200 Be = 9,4 Mg = 24 Zn = 65,2 Cd = 112 B = 11 Al = 27,4 ? = 68 Ur = 116 Au = 197? C = 12 Si = 28 ? = 70 Sn = 118 N = 14 P = 31 As = 75 Sb = 122 Bi = 210? O = 16 S = 32 Se = 79,4 Te = 128? F = 19 Cl = 35,5 Br = 80 I = 127 Li = 7 Na = 23 K = 39 Rb = 85,4 Cs = 133 Tl = 204 Ca = 40 Sr = 87,6 Ba = 137 Pb = 207 ? = 45 Ce = 92 ?Er = 56 La = 94 ?Yt = 60 Di = 95 ?In = 75,6 Th = 118? (Mendeleev uses Pl for Pd; Ur for Uranium) In 1871 Mendeleev published an updated version of his periodical table. He turned it 90 degrees: I. — R2O II. — RO III. — R2O3 IV. RH4 RO2 V. RH3 R2O5 VI. RH2 RO3 VII. RH R2O7 VIII. — RO4 1 H = 1 2 Li = 7 Be = 9,4 B = 11 C = 12 N = 14 O = 16 F = 19 3 Na = 23 Mg = 24 Al = 27,3 Si = 28 P = 31 S = 32 Cl = 35,5 4 K = 39 Ca = 40 – = 44 Ti = 48 V = 51 Cr = 52 Mn = 55 Fe = 56, Co = 59, Ni = 59, Cu = 63 5 (Cu = 63) Zn = 65 – = 68 – = 72 As = 75 Se = 78 Br = 80 6 Rb = 85 Sr = 87 ?Yt = 88 Zr = 90 Nb = 94 Mo = 96 – = 100 Ru = 104, Rh = 104, Pd = 106, Ag = 108 7 (Ag = 108) Cd = 112 In = 113 Sn = 118 Sb = 122 Te = 125 I= 127 8 Cs = 133 Ba = 137 ?Di = 138 ?Ce = 140 – – – - - - - 9 (–) – – – – – – 10 – – ?Er = 178 ??La = 180 Ta = 182 W = 184 – Os = 195, Ir = 197, Pt = 198, Au = 199 11 (Au = 199) Hg = 200 Tl = 204 Pb = 207 Bi = 208 – – 12 – – – Th = 231 – U = 240 – This table is from Mengyelejev periódusos rendszere (note). On 29 November 1870, Mendeleev took his concept even further by stating that it was possible to predict the properties of undiscovered elements. He then proceeded to make predictions for three new elements (eka-aluminum, eka-boron and eka-silicon, red in the above table, eka = one (Sanskrite)) and suggested several properties of each, including density, radii, and combining ratios with oxygen, among others. The science world was perplexed, and many scoffed at Mendeleevs predictions. It was not until November, 1875, when the Frenchman Lecoq de Boisbaudran discovered one of the predicted elements (eka-aluminum) which he named Gallium, that Mendeleevs ideas were taken seriously. The other two elements were discovered later and their properties were found to be remarkably similar to those predicted by Mendeleev. These discoveries, verifying his predictions and substantiating his law, took him to the top of the science world. He was 35 years old when the initial paper was presented There was a problem with Mendeleevs table. If the elements were arranged according to increasing atomic masses, Tellurium and Iodine seemed to be in the wrong columns. Their properties were different from those of other elements in the same column. However, they were next to each other. Switching their positions put them in the columns where they belonged according to their properties. If the switch were made, Mendeleevs basic assumption that the properties of the elements were a periodic function of their atomic masses would be wrong. Mendeleev assumed that the atomic masses of these two elements had been poorly measured. He thought that new mass measurements would prove his hypothesis to be correct. However, new measurements simply confirmed the original masses. Soon, new elements were discovered, and two other pairs showed the same kind of reversal. Cobalt and Nickel were known by Mendeleev, but their atomic masses had not been accurately measured. When such a determination was made, it was found that their positions in the table were also reversed. Henry Moseley 1913 When Argon was discovered, the masses of Argon and Potassium were reversed. Henry Moseley found the reason for these apparent exceptions to the rule. As a result of Moseleys work, the periodic law was revised. He stated that physical and chemical properties are a periodic function of their atomic number, rather than mass. This better explained the gaps in the table. The atomic number of an element indicates the number of protons in the nucleus of each atom of the element. The atomic number also indicates the number of electrons surrounding the nucleus. Herewith he created the modern periodic table in which each succeeding element has one more proton and electron than the former element. Further reading (random selection): J.W. van Spronsen, The Periodic System of Chemical Elements. Elsevier, 1969. The Mendeleev Puzzle (note). The Periodic Table (note). Classification of elements (note). Classification of the Elements (note). Mark R. Leach, The Chemogenesis Webbook, A Selection of Periodic Tables © Peter van der Krogt
Posted on: Sat, 26 Jul 2014 05:16:14 +0000
Trending Topics
Recently Viewed Topics
© 2015