Question

Which of the following sets of atomic masses do not correspond to Dobernier traid?

• A. $7,23,39$
• B. $20,38,56$
• C. $47,91,178$
• D. $54,95,183$

Answer 1

Answer: (C), (D)

The correct options are
C $54,95,183$
D $47,91,178$

The following sets of atomic masses do not correspond to Dobernier traid.
(C) $47,91,178$
(D) $54,95,183$
In these sets, the atomic mass of middle element is not equal to the mean of atomic masses of first and last element.
$91\ne \frac{47+178}{2}$
$95\ne \frac{54+183}{2}$