Question

What is the basis of the Doberenier's triad explain?

Answer 1

Explanation of Dobereiner’s triads

• According to J.W. Doberiner, the chemically similar elements were arranged in the increasing order of their atomic weights in the group of three to make a triad. It was noted that the atomic weight of the middle element present in the triad is the mean of the other two elements.

Element	Atomic mass	Average
Lithium Sodium Potassium	7 23 39	$\frac{7+39}{2}=\frac{46}{2}=23$
Calcium Strontium Barium	40 88 137	$\frac{40+137}{2}=\frac{177}{2}=88.5$
Chlorine Bromine Iodine	35.5 80 127	$\frac{35.5+127}{2}=\frac{162.5}{2}=81.25$