元素周期律的发现者门捷列夫 - 毕业生生列表（Mendeleev, Graduate discoverer of the periodic law of the elements -- list of graduates）.doc

元素周期律的发现者门捷列夫 - 毕业生生列表（Mendeleev, Graduate discoverer of the periodic law of the elements -- list of graduates） Mendeleev, discoverer of the periodic law of elements One of the greatest chemists of the nineteenth Century. His book principles of Chemistry (1868-1871), a Book of various editions, has a great influence on inorganic chemists. When Mendeleev in 1869 in the preparation of the chemical principle this textbook, he must be based on a system of elements of the language, in order to arrange the content not to causal factors but with certain scientific principle as a guiding principle. This principle does not depend on accidental, non essential features, but on matters closely related to the nature of matter itself. By the year 1869, 63 elements had been recognized. In the extensive study of matter and elements, the accumulation of information about the properties of various elements is becoming richer and richer, but these data are complicated and difficult to obtain a clear understanding of. Sorting out these materials, summarizing these perceptual knowledge, trying to sum up the rules, is a problem that should be solved urgently before chemists at that time. It is also the inevitable requirement of the development of science and production. Discovery of periodic law of chemical elements After Dalton put forward the theory of atomic science, many chemists took the determination of the atomic weight of various elements as an important work, so that the relationship between the atomic weight and the nature of the elements gradually revealed. In 1829, the German chemist Debay Rainer put forward the three elements point of view, the 15 elements were known in 44, divided into 5 groups, each group pointed out that the three properties of the elements are similar, and the atomic weight of the middle element is equal to two atomic weight lighter and heavier and half. For example, calcium, strontium and barium are similar in nature, and the atomic weight of strontium