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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?
Solution
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.
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