Question

Define the Dobereiner's law of triads.write the reason for its failure.

Answer 1

One of the Early attempts of Classification of elements was done by Dobereiner.

He found Triads which are groups of three elements with similar properties. He observed that when the three elements are arranged in Increasing order of their Atomic mass, the mass of the middle element was the average of the mass of other two elements of the same triad.

The reason of its failure was that he could find only three such triads.

Hence the classification was not useful.