Question

Atomic wt. of P is 31 and Sb is 120. What will be the atomic wt. of As, as per Dobernier triad rule?

• A. $151$
• B. $75.5$
• C. $89.5$
• D. Unpredictable

Answer 1

The correct option is B $75.5$

Atomic wt. of P is 31 and Sb is 120. The atomic wt. of As, as per Dobernier triad rule will be average of two. It will be $\frac{31+120}{2}=\frac{151}{2}=75.5$