Question

Give three points of difference between mendeleev's table and modern Periodic table.

Answer 1

What is the difference between Mendeleev and Modern Periodic Table?

• Modern periodic table contains about 103 elements, in Mendeleev periodic table there were only about 66 elements.

• The basis of the modern periodic table is mainly the electronic configuration of the elements, we called it atomic number, whereas in Mendeleev’s time he considered the atomic mass of the elements.

• In Mendeleev periodic table, there were gaps for un-discovered elements, but modern periodic table has a uniformity.

• Both of these classifications consider the periodic relationship in properties of the elements.

• Both, Mendeleev and Modern, periodic tables are used to predict chemical and physical properties of unknown elements.

• In classification, both had arranged elements in groups or families.

Mendeleev vs Modern Periodic Table Summary

Mendeleev periodic table was based on the increasing atomic masses and the modern periodic table is based on the increasing atomic numbers. The elements with similar chemical and physical properties recur at definite intervals in the modern periodic table. In modern periodic table, there are about 103 elements. When Mendeleev classified them, there were only 66 elements in the periodic table. However, Mendeleev left places empty in his periodic table for the un-discovered elements. He also assumed the periodic variation of properties in elements.

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!!!