Question

Which of the following elements is isodiapher of ${}_{92}^{235}\text{U}$?

• A. ${}_{83}^{209}\text{Bi}$
• B. ${}_{82}^{212}\text{Pb}$
• C. ${}_{90}^{231}\text{Th}$
• D. ${}_{91}^{231}\text{Pa}$

Answer 1

Answer: (C)

${}_{90}^{231}\text{Th}$

Isodiaphers : They are the atoms of different element which have the same difference of the number of neutrons & protons.
Here, for both ${}_{92}^{235}\text{U}$ and ${}_{90}^{231}\text{Th}$ $n-p=51$.