Question

Wht were the limitations of Mendeleev's Periodic Table?*​

Answer 1

Answer:

The Limitations of Mendeleév's Periodic Table are:

1) In Mendeleév's Periodic Table, there is no fixed position for Hydrogen

Exaplanation - It's electroninc configution resembles that of alkali metals and like alkali metals, it reacts with oxygen, sulphur and halogens to form compounds. Also, like halogens, it exists as a diatomic molecule (H2) and reacts with metals and non metals to form covalent bonds.

2) The isotropes of elements were discovered much later. This posed a challenge to Mendeleév's Periodic Table.

3) It was difficult for Mendeleév to predict how many elemnts would be discovered later. So the atomic number of the elements in Mendeleév's table didn't increase in a regular manner.

Answer 2

Limitations of the Mendeleev periodic table are listed below.




Elements with large differences in properties were included in the same group. for example, hard metals like copper and silver were included along with soft metals like sodium and potassium.



No proper position could be given to the element hydrogen. In the periodic table, the location of hydrogen is uncertain. It was put with alkali metals within 1A class, but certain hydrogen properties are close to those of halogens. So, it can also be put for halogens in the band.


The increasing order of atomic mass was not strictly followed throughout. For example in cobalt and nickel & Tellurium and Indium.


As isotopes are atoms of the same element having different atomic masses, they should have been given different positions while arranging them in the order of atomic mass. But this was not done.