Question

For the radioactive nuclei that undergo either $\alpha$ or $\beta$ decay, which one of the following cannot occur?

• A. Isobar of original nucl us is produced
• B. Isotope of the original nucleus is produced
• C. Nuclei with higher atomic number than that of the original nucleus is produced
• D. Nuclei with lower atomic number than that of the original nucleus is produced

Answer 1

Answer: (B)

Isotope of the original nucleus is produced

In beta decay, the mass number of the original nucleus is unchanged, and hence the new nucleus is an isobar of the original one.

In a ${\beta }^{-}$ decay, the number of protons in the nucleus decreases, and that in ${\beta }^{+}$ and $\alpha$ decay increases. Hence it cannot form an isotope.
Hence correct answer is option B.