Question

solve the answer of chemistry

Answer 1

doberener's traid means average of first and third element is equal to the atomic mass of third element
that is A+B/2
=7+39/2
=46/2
=23

Answer 2

If atomic mass of A is 7
& B is 39
according to dobereiner triad
B=A+C/2
7+39/2
46/2
= 23



so answer is option A)23






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