Question

give reason Mendeleev's's contribution to the periodic table laid the foundation of the modern periodic table

Answer 1

He arranged elements according to the atomic mass. He gave periodic law. He arranged elements into periods and groups. He left space for those elements which were not discovered at that timelike eka- aluminum etc

Answer 2

Mendeleev contribution to the periodic table let the foundation of the modern periodic table in the following ways:

- By arranging the elements and by showing the periodicity of the properties of the element medley blood the foundation for Modern Periodic Table .

- There are 63 elements that are known into 8 groups by leaving gaps for undiscovered elements and predicting their properties.

- In the modern periodic table he made separate Groups for metals and non - metals ,

- Periodic law was made by him in which he separate elements on the basis of their atomic mass.

- He also separated elements into different groups and periods.