Question

Achievement of Mendeleev periodic table

Answer 1

Mendeleev kept some blank spaces in the periodic table for the elements that were yet to be discovered.

Answer 2

________Answer_______

Mendeleev's Periodic Table :-

=>The physical and chemical properties of elements are periodic function of their atomic mass .

Achievements :-

• In order to adjust elements in his periodic table the sequence was inverted in which elements with slightly greater atomic mass were placed before the element with Lower atomic mass.

• for example:- Cobalt (Co) with atomic mass 58.93 and Nickel (Ni) with 58.71

• He left some gaps from the Undiscovered periodic table . He predicted the existence of some element that had not been discovered.

• He named them by prefixing Sanskrit numeral Eka(one) to the name of preceding element in the same group.

• for example:- Scandium,Gallium, Germanium discovered later has properties to Eka- Boron( Scandium) , Eka - aluminium (Gallium) , Eka -silicon (Germanium)

• Noble gases which were discovered later could be placed in new group without disturbing the existing order.

__________Thank you ☺