Atomic mass of Cl =35.5 u and that of I =127 u. According to Dobereiner's triad rule, atomic mass of Br will be u.

Question

Atomic mass of Cl =35.5 u and that of I =127 u. According to Dobereiner's triad rule, atomic mass of Br will be u. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

According to Dobereiner, the middle element has an atomic mass almost the average of the other two elements. Hence, (35.5+127/2)=81.25 u

Q. Atomic mass of $Cl = 35.5 u$ and that of $I = 127 u$ . According to Dobereiner's triad rule, atomic mass of $B r$ will be____ $u$ .