Question

Write dobereiner traids
characteristics and limitations

Answer 1

Limitations of Dobereiner's classification: Dobereiner could find only three triads; .i.e total of 9 elements only. However the total number of elements were more than that of those encompassed in Dobereiner's Triad. Thus, Dobereiner's could not be classify most of the elements known at that time.

Answer 2

Characteristics of Dobereiner’s triads :

See the attached image (Created by me)

(a) Properties of elements in each triad were similar.

(b) Dobereiner showed that when three elements in a triad were written in the order of their increasing  atomic masses,

The atomic mass of the middle element was roughly the average of the atomic masses  of the other two elements

Limitation of Dobereiner’s triads :

Dobereiner could identify only three triads. He was not able to  prepare triads of all the known elements