Question:
The three elements A, B and C with similar properties have atomic masses X, Y and Z respectively. The mass of Y is approximately equal to the
average mass of X and Z. What is such an arrangement of elements called as ? Give one example of such a set of elements.
Solution:
The arrangement is known as Dobereiner’s triad. For example, Calcium (Ca), Strontium (Sr) and Barium (Ba).