Question

Compare the arrangement of elements in Mendeleev's periodic table and the modern periodic table.

Answer 1

Mendeleev:

1. Arranged in increasing atomic mass

2. 7 groups and 6 periods

3. No fixed position for Hydrogen

4. No separation between metals and non metals

5. No possible accompaniment for isotopes

Modern:
1. Increasing atomic number

2. 18 groups, 7 periods

3. Hydrogen placed above alkaline metals

4. Clear distinction between metals and non metals

5. Isotopes can be accompanied

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!!!