what is the need to classify elements on the basis of modern and mendeleevs periodic table?

Dear Student , 

Please find below the solution to the asked query:

There are 118 elements known today out of which some elements are man made.It is a very difficult task to study the properties of such a large number of elements and their compounds individually. So, if the elements with similar properties are grouped together or classified it would rationalize the known chemical facts and it would be easy to  predict new ones.
 

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Akanksha