Question

What is the main difference between Mendeleev's and
modern periodic law? How does this difference be found
helpful for improving the drawbacks of Mendeleev's periodic
table?​

Answer 1

Explanation:

Medeleev designed his periodic table with the help of atomic weight whereas the modern periodic table is drawn on the basis of atomic number.

The difference is helpful as all different elements have different atomic number whereas if we follow atomic mass we may have certain elements that have very similar atomic mass and even within the same elements the mass of isotopes vary.

Answer 2

Answer:

• Mendeleev's periodic table

1. elements are arranged in increasing order of their atomic masses.
2. It is not divided into any blocks.
3. There are 8 groups.
4. Isotopes could not be placed properly.

• Modern periodic table

1. Elements are arranged in increasing order of their atomic numbers.
2. It is divided into four blocks, namely s-block,p-block,d-block and f-block.
3. There are 18 groups.
4. Isotopes occupy the same position as the element.

Hope you understood mate!!!