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Important contribution of Mendeleev's periodic table. |
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Answer» SOLUTION :Mendeleev.s PERIODIC table was one of the greatest achievements in the development of chemistry. Some of the important contributions of his periodic table are: (A) Systematic study of the elements : The Mandeleev.s periodic table simplified the study of chemistry of elements. KNOWING the properties of one element in a group the properties of other element in the group can be easily guessed. Thus, if became very useful in studying and remembering, the properties at a large number of elements. (B) Correction of Atomic mass : The mandeleev.s periodic table helped in correcting the atomic massed of some elements BASED on their positions in the table. For example, atomic mass of beryllium was corrected from 13.5 to 9. Similarly, with the help of this table atomic masses of indium, gold, platinum etc. were corrected. (C) Prediction of new elements : At the time of Mendeleev, only 56 elements were known. While arranging these element, he left some gaps. These gaps represented the undiscovered elements. Mendeleev predicted the properties of these undiscovered elements on the BASIS of their positions. For example he predicted the properties of these undiscovered later. The observed properties of these elements were found to be similar to those predicted by Mendeleev.  (D) Empty space for undiscovered elements or empty space for EKa Aluminum and Eka silicon. His Primary aim of a arranging the elements of similar properties in the same group. He proposed that some of the elements were still undiscovered therefore left several gaps in the table. (For Gallium & Silicon) Example-1 : Galium was not discovered when Mendeleeve published periodic table so he placed empty space and named Eka Aluminium. Example-2 : Germanium was not discovered when Mendeleev published periodic table so he placed empty space under the silicon and named Eka Silicon. Where later Germanium is found. Mendeleev.s Predictions for the Elements Eka-aluminium (Gallium) and Eka-sillicon (Germanium)  (E) Medelee.s periodic table published in 1905 is shown at back page in figure . 
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