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. He added that, "unfortunately there also a number of freaks". ![]() In 1954, Tomkeieff referred to the three principle types of periodic table as helical, rectilinear, and spiral. To a lesser extent, the more involved two-dimensional arrangements do little toward solving the difficulty, and essentially the only suggestions as to modifications which are truly constructive are those centering in reflection of electronic configurations.Ĭertainly the most useful of these modifications, and at the same time one of the earliest to be proposed, is the so-called long or. Thus the many three-dimensional models, embracing globes, helices, cones, prisms, castles, etc., are interesting but lacking in utility. Geometry does not permit of an arrangement which is sufficiently ideal to serve all the required purposes equally well. Unfortunately, the majority of the tabulations proposed are either unwieldy or utterly worthless, and only a few valuable suggestions have been made. In fact so many modifications have appeared that one is tempted to conclude that practically every author has his own concept of what a workable arrangement must be. The literature is replete with suggested (and discarded) modifications of the M periodic table. In 1952, Moeller expressed disdain as to the many types of periodic table: 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. His objection was that he could not express this function mathematically." Typology On spiral periodic tables, "Mendeleev.steadfastly refused to depict the system as. 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". This would mean that indium’s atomic mass was actually 113, placing the element between two other metals, cadmium, and tin.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.Įarlier, in 1869, Mendeleev had mentioned different layouts including short, medium, and even cubic forms. Because elemental indium is a silvery-white metal, however, Mendeleev postulated that the stoichiometry of its oxide was really In 2O 3 rather than InO. If this atomic mass were correct, then indium would have to be placed in the middle of the nonmetals, between arsenic (atomic mass 75) and selenium (atomic mass 78). The atomic mass of indium had originally been reported as 75.6, based on an assumed stoichiometry of InO for its oxide. He discovered, for example, that the atomic masses previously reported for beryllium, indium, and uranium were incorrect. ![]() When the chemical properties of an element suggested that it might have been assigned the wrong place in earlier tables, Mendeleev carefully reexamined its atomic mass. The observed properties of gallium and germanium matched those of eka-aluminum and eka-silicon so well that once they were discovered, Mendeleev’s periodic table rapidly gained acceptance. Two of the blanks Mendeleev had left in his original table were below aluminum and silicon, awaiting the discovery of two as-yet-unknown elements, eka-aluminum and eka-silicon (from the Sanskrit eka, meaning “one,” as in “one beyond aluminum”).
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