Question

Write two main draw back of mandeleav,s periodic table

Answer 1

#no proper place for hydrogen

#no places for isotopes of elements

#the arrangement of elements weren't properly arranged in increasing p

order

Answer 2

Two main drawbacks were:

1) Mendeleev took the atomic masses of the elements as the basis of his arrangement and so arranged the elements in the order of increasing atomic masses but there were some pairs known as anomalies which defied the basis of his arrangement such as Nickel and Cobalt.

2)The isomers of elements i.e. atoms of the same element having different atomic masses had no separate column in the Mendeleev table.

3)The position of Hydrogen was not fixed.