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Mendelleves advantage and drawback |
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Answer» ..☆☆ MENDELEEV'S PERIODIC LAW ☆☆¤¤ By Evonvich Mendeleev in 1872. According to his law, " The physical and chemical properties of ELEMENTS are periodic functions of their atomic masses".¤¤ He gave 9 veritcal columns CALLED groups.¤¤ He gave 7 horizontal columns called periods.☆☆ ADVANTAGES OF MENDELEEV'S PERIODIC LAW ☆☆¤¤ He gave simplified and systematic way for study of elements.¤¤ He left space for the elements which were not discovered at that time and gave NIGHT prediction. ¤¤ He gave CORRECTION in atomic weights of some elements. E.g. Be was 13.5 and was corrected to "9".☆☆ DRAWBACKS OF MENDELEEV'S PERIODIC LAW ¤¤ He could not identify position of hydrogen exactly. ¤¤ The arrangement according to atomic weight was not correct.¤¤ No space for Isotopes.¤¤ Lanthanoids and Actinoids were not given proper position.¤¤ Dissimilar elements grouped together. E.g. Li, Na, K with Cu, Ag and AU. |
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