From the following set of the elements and their atomic masses obtain Dobereiner’s triad: Element - Atomic mass

Question

From the following set of the elements and their atomic masses obtain Dobereiner’s triad:

Element	Br	K	I	Cl
Atomic mass	35.5	79.9	126.9	35.5

Answer 1

Among the given four elements, the three elements in the increasing order of atomic masses and having similar properties are

Element	Br	K	I
Atomic mass	35.5	79.9	126.9

Hence, the above three elements represent Dobereiner’s triad.