Question

1. Why classification on the basis of law of traids was rejected?
2. Mention two problems which are unresolved in original Mendeleev's periodic classification.​

Answer 1

Answer:

The law of triads was rejected because Doberiener failed to arrange all the known elements in form of triads. ... Note_The atomic mass of the middle element of a triad was approximately equal to arithmetic mean (average)of the atomic masses of the other two elements of that triad. But,taking halogens,viz.