Question

what are drawbacks of Mendleevs periodic table

Answer 1

this is the answer....

Answer 2

Heya !!

Limitations of Mendeleev's periodic table are as follows:

Although this table was greatly helpful for the study of elements but a few anomalies could not be explained on the basis of this table. These anomalies are :


1. POSITION OF HYDROGEN

The electronic configuration of hydrogen resembles with alkali metals. Moreover, it combines with halogen, oxygen and sulphur to give similar type of compounds as given by alkali metals, e.g. ( HCL, NaCl ) , ( H2O, Na2O ) etc. But just like halogen it exists in diatomic form and combines with metals and nonmetals to form covalent compounds. Thus , its position was not fixed in the Mendeleev's periodic table
but it was kept with alkali metals.



2. POSITION OF ISOTOPES

Isotopes of the elements, have similar chemical properties but different atomic masses. In Mendeleev's periodic table, no place was given to these elements.



3.UNCERTAINTY IN ATOMIC MASSES

Another problem was that the atomic masses do not increase in a regular manner in going from one element to the next.
So, it was not possible to predict how many elements could be discovered between two elements especially when we consider the heavier elements.



4. PLACING OF HEAVIER ELEMENT BEFORE THE LIGHTER ONE

Few elements, those possess higher atomic mass where placed before elements having a lower atomic mass.