Question

Which of the following nuclides belong to actinium $\left(U^{235}\right)$ series ?

• A. $P{b}^{207}$
• B. $P{o}^{215}$
• C. $P{o}^{213}$
• D. ${}_1{H}^3$

Answer 1

Answer: (A), (B)

The correct options are
A $P{b}^{207}$
B $P{o}^{215}$

$P{b}^{207}$ and $P{o}^{215}$ belong to actinium $\left(U^{235}\right)$ series.

Actinium series is 4n+3 series. Here remainder is three when the mass number is divided by four.

This series involves emission of 7 alpha and 4 beta particles.