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The Periodic System 周期系统

The Periodic Table Pub Date : 2019-12-12 DOI: 10.1093/oso/9780190914363.003.0006

Eric R. Scerri

{"title":"The Periodic System","authors":"Eric R. Scerri","doi":"10.1093/oso/9780190914363.003.0006","DOIUrl":"https://doi.org/10.1093/oso/9780190914363.003.0006","url":null,"abstract":"In ancient Greek times, philosophers recognized just four elements—earth, water, air, and fire—all of which survive in the astrological classification of the 12 signs of the zodiac. At least some of these philosophers believed that these different elements consisted of microscopic components with differing shapes and that this explained the various properties of the elements. These shapes or structures were believed to be in the form of Platonic solids (figure 1.1) made up entirely of the same two-dimensional shape. The Greeks believed that earth consisted of microscopic cubic particles, which explained why it was difficult to move earth. Meanwhile, the liquidity of water was explained by an appeal to the smoother shape possessed by the icosahedron, while fire was said to be painful to the touch because it consisted of the sharp particles in the form of tetrahedra. Air was thought to consist of octahedra since that was the only remaining Platonic solid. A little later, a fifth Platonic solid, the dodecahedron, was discovered, and this led to the proposal that there might be a fifth element or “quintessence,” which also became known as ether. Although the notion that elements are made up of Platonic solids is regarded as incorrect from a modern point of view, it is the origin of the very fruitful notion that macroscopic properties of substances are governed by the structures of the microscopic components of which they are comprised. These “elements” survived well into the Middle Ages and beyond, augmented with a few others discovered by the alchemists, the precursors of modern-day chemists. One of the many goals of the alchemists seems to have been the transmutation of elements. Not surprisingly, perhaps, the particular transmutation that most enticed them was the attempt to change the base metal lead into the noble metal gold, whose unusual color, rarity, and chemical inertness have made it one of the most treasured substances since the dawn of civilization.","PeriodicalId":440562,"journal":{"name":"The Periodic Table","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129802360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Forms of the Periodic Table 元素周期表的形式

The Periodic Table Pub Date : 2019-12-12 DOI: 10.1093/oso/9780190914363.003.0018

Eric R. Scerri

{"title":"Forms of the Periodic Table","authors":"Eric R. Scerri","doi":"10.1093/oso/9780190914363.003.0018","DOIUrl":"https://doi.org/10.1093/oso/9780190914363.003.0018","url":null,"abstract":"A good deal has been said about the periodic table in previous chapters, but one important aspect has not yet been addressed. This is the question of why so many different periodic tables have been published in textbooks, articles, and on the Internet. One may also wonder whether there exists an “optimal periodic table” and whether such a question even makes sense. Assuming it is a legitimate question, one would like to know what progress has been made toward identifying such an optimal table. Before plunging into this further aspect of chemical periodicity, at least two kinds of differences among periodic tables should be distinguished. First, there is the question of whether the table is presented as having 8, 18, 32, or even higher numbers of columns. Second, there is the question of variations among tables concerning the placement of specific elements such as hydrogen, helium, lanthanum, actinium, lutetium, and lawrencium. In a classic, though flawed, book on the history of the periodic table, Edward Mazurs included illustrations as well as references to about 700 periodic tables that have been published since the periodic table was first assembled in the 1860s. In the 45 or so years that have elapsed since the publication of Mazurs’s book, at least another 300 tables have appeared, not to mention the numerous new periodic systems posted on the Internet. The fact that so many periodic tables exist is something that requires an explanation. Of course, many of these tables may not have anything new to offer, and some are even inconsistent from a scientific point of view. But even if we were to eliminate these misleading proposals, a very large number of tables still remain. In chapter 1, we saw that there are three basic forms of the periodic table: the short form, the medium-long form, and the long form. All three convey very much the same information, although the grouping of elements with the same valence is treated differently in each of these formats.","PeriodicalId":440562,"journal":{"name":"The Periodic Table","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126034098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

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