�Essay of CHEM1351

â� Essay of CHEM1351 - chemical reaction. Third,...

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There are five parts to explain about a history of the Periodic Table.  First   of   all,   in   1803,   John   Dalton   proposed   a   model   to   explain   the  accumulating experimental data. The important points of Dalton’s atomic theory are  four. One is all matter is composed of extremely small particles called atoms. Second is  all atoms of a given element are alike, but atoms of one element differ from the atoms  of any other element. Third is compounds are formed when atoms of different elements  combine   in   fixed   proportions.   The   last   one   is   a   chemical   reaction   involves   a  rearrangement   of   atoms.   No   atoms   are   created,   destroyed,   or   broken   apart   in   a 
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Unformatted text preview: chemical reaction. Third, Berzelius was the first person to prepare an extensive list of atomic weights in 1828 containing 54 elements. Forth, in 1869, Mendeleev, the Russian chemist, invented the periodic table that arranged the elements primarily in order of increasing atomic mass, although in a few cases he put a slightly heavier element before a lighter one in order to place elements with similar chemical properties in the same column. Also, he predicted three unknown elements he called eka-boron, eka-aluminum, and eka-silicon were soon discovered and named scandium, gallium, and germanium. Fifth, Moseley in 1912...
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