Question

Write down five major differences between mendeleev's periodic table and modern periodic table.

Answer 1

mendaleevs periodic table consists of 9 verticle columns is called group
they are numbered from one to eight and zero each groups.
one to seven is sub divided into sub groups.
and seven horizontal Raw's called period.

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!!!