Question

what are the disadvantage of periodic table

Answer 1

hydrogen resemble both alkali metals and halogens but it has been placed with alkalis.the lanthanides and acitinides have not been placed in the main body of the table.place of element is no sure in the modern periodic table.some similar elements are separated,while some dissimilar elements have been placed in th group.presence of some anomalous pairs of elements.the isotopes of an element have no place in the periodic table.

Answer 2

Drawbacks of modern periodic table-
1.hydrogen resembles both the alkali metals and halogens.but it has been placed with the alkalis.
2.the lanthanides and actinides have not been placed in the main body of the table.