Question

Why was the system of classification of elements into triads not found suitable?

Answer 1

The system of classification of elements into triads was not found suitable because it failed to arrange all the then-known elements in the form of triads of elements having similar chemical properties. Only three triads from the elements known at that time could be identified.

(i) Only a few similar elements could be grouped into triads and quite a large number of elements were left out.

(ii) It was also not possible to group quite dissimilar elements into triads.