achievement of mendeleev periodic table
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Answer:
In 1869, Mendeleev made remarkable contribution to the classification of elements. He gave a law known as periodic law. The law states that the physical and chemical properties of elements are periodic function of their atomic weights .
On the basis of this periodic law, he arranged all the known elements in the form of table known as periodic table. It was observed that, elements with similar properties recur at regular intervals or periodically. In the Mendeleev's periodic table, horizontal rows are called periods and vertical columns are called groups. The Mendeleev's classification gave him so much confidence that he boldly left certain spaces or gaps for undiscovered elements.
Achievements of the Mendeleev's periodic tables are as under:-
1) Systematic study of elements:-
As the elements having same properties are grouped together so it becomes very useful to remember the properties of large number of elements in a systematic way.
2) Prediction of new elements:-
Mendeleev predicted the properties of those missing elements from the known properties of the other elements in the same group. On the basis of this, he named Gallium as Eka-Aluminum, Germanium as Eka-Silicon and Scandium as Eka-Boron.
3) Correction of atomic mass:-
Atomic mass of beryllium was corrected from 13.5 to 9. Atomic mass of indium, gold and platinum were also corrected.
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