Question

A, B and C are the elements of a Dobereiner's triad. If the atomic mass of A is 7 and that of C is 39, what should be the atomic mass of B?

Answer 1

At. wt. of A = 7, At. wt. of C = 39

At wt. of B = `("At.wt. of A + At. wt. of C")/2 = (7 + 39)/2 = 23`

At. wt. of B = 23

i.e Average of weights of A and C.