Question

what were the 2 major shortcomings of mendeleev's periodic table ?how have these been removed in the modern periodic table ?

Answer 1

psition of hydrogen was not cleared and two elements are arranged in one column

Answer 2

● Drawbacks in Mendeleev's periodic table -
- Position of Hydrogen is not explained.
- Metals & non-metals mixed up.
- Isotopes of same element placed at different positions.
- No place for inert gases.

● Improvements in modern periodic table -
- Hydrogen placed above alkali metals.
- Metals & non-metals are separated.
- Isotopes of same element placed at same position.
- Inert gases are placed in separate group. i.e. gr.18.

Hope this helps you.