Question

List any two distinguishing features between Mendeleev's Periodic
Table and the Modern Periodic Table.
With the help of an example, explain Dobereiner's Triads.
State Modern Periodic Law.​

Answer 1

Answer:

As per Mendeleev's Periodic Law, the

physical and chemical properties of the elements are a periodic function of their atomic weight.

Modern Periodic Law the physical and chemical properties of the elements are a periodic function of their atomic number.

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!!!