He grouped the elements with similar properties into clusters of three called triads
the distinct feature of triad was the atomic mass of middle element
the atomic mass of middle element was approximately the arithmetic mean of other two elements in a triad
dobereiner could only classify 3 triads successfully .
  • Brainly User
He noted a similarity among the physical and chemical properties of several groups of three elements (Triads).
In each case, he noticed that the middle element of each of the Triads had an atomic weight about half way between the atomic weights of the other two. Also the properties of the middle element were in between those of the other two members. Since Dobereiner’s relationship,referred to as the Law of Triads, seemed to work only for a few elements, so it was dismissed.