Question

On what basis were the elements arranged in Dobereiner's trialds.
triads? ( )
a. atomic number
b.atomic mass
c. Number of protons.
d. number of elections
PLZ SAY ONLY CORRECT OPTION PLZ SAY FAST URGENT ​

Answer 1

and is. a

I hope it will be right

Answer 2

b. Atomic mass is the correct answer.

For a group to be Dobereiner's triad, the atomic mass of middle element must be average of atomic masses of the first and the third elements.