Can the following groups of elements be classified as Dobereiner's triad ?
(a) Na, Si, Cl
(b) Be, Mg, Ca
Atomic mass of Be 9 , Na 23 , Mg 24 , Si 28 , Cl 35 , Ca 40
Explain by giving reason.

Answer

(a) No. This is because the elements `Na, Si` and `Cl` do not have similar properties even though the atomic mass of middle elements `Si` is almost equal to the average atomic mass of first element `Na` and third element `Cl` (b) Yes This is because is the elements `Be, Mg` and `Ca` have similar properties and the atomic mass of middle element `Mg` is almost equal to the average atomic mass of first element `Be` and third element `Ca`

Explanation

NA