Question

The group of element formed in the final stage of radioactive change, $\begin{array}{cc}{}_{90}T{h}^{231}& \stackrel{-\beta }{\to }{}_{91}{X}^{231}\end{array}$ will be :

• A. Group 3
• B. Group 2
• C. Group 5
• D. Group 4

Answer 1

Answer: (A)

Group 3

The element with atomic number 91 is Protactinium.

So, X is Protactinium which lies in the group - 3 and 7th period.