Question

What were the early attempt to classify the elements

Answer 1

A German chemist and professor, Dobereiner's attempt at classification of elements are generally considered the first recorded attempt. He identified elements with similar properties and grouped them into groups of three, hence the name “triads”.

Answer 2

First person was Dobineer traids
He arranged the elements in such a way that
the average of first and third element gave the
mass of second element