Question

Three elements of Dobereiner’s triad are X, Y & Z. If the atomic mass of X is 7 and Z is 39, Calculate the atomic mass of Y.

Answer 1

Explanation:

answer is 23. which is the atomic mass of y

Answer 2

Atomic mass of Y = 23

Explanation:

According to the Dobereiner's triad, when elements are arranged in the order of increasing atomic masses, groups of three elements having similar chemical properties are obtained. The atomic mass of the middle element of the triad will be equal to the arithmetic mean of the atomic masses of the other two elements in the triad.

X, Y, Z are a Dobereiner's triad. So atomic mass of Y will be the arithmetic mean of atomic masses of X and Z.

Atomic mass of Y = (Atomic mass of X + atomic mass of Z) / 2

= (7 + 39) / 2

= 46 / 2

= 23