Question

The nucleus $^{115}_{48}Cd$, after two successive $\beta$-decay will give

• A. $^{115}_{46}Pa$
• B. $^{114}_{49}ln$
• C. $^{113}_{50}Sn$
• D. $^{115}_{50}Sn$

Answer 1

The Correct Option is D

The question involves understanding the process of beta decay and predicting the daughter nucleus after successive decays.

Beta decay is a type of radioactive decay in which a beta particle (electron or positron) is emitted from an atomic nucleus. The beta decay process does not change the mass number, but it increases the atomic number by 1 when an electron is emitted (beta-minus decay), or decreases the atomic number by 1 when a positron is emitted (beta-plus decay).

The original nucleus given is $^{115}_{48}Cd$. During beta-minus decay, a neutron is converted into a proton, and an electron (beta particle) is emitted. Hence, the atomic number increases by 1.

1. First Beta Decay: $^{115}_{48}Cd \rightarrow ^{115}_{49}In$ (Indium is the daughter nucleus).
2. Second Beta Decay: $^{115}_{49}In \rightarrow ^{115}_{50}Sn$ (Tin is the final daughter nucleus).

Following these two beta decay processes, the nucleus transforms into $^{115}_{50}Sn$.

Let's evaluate the options:

• $^{115}_{46}Pa$: Incorrect, as both atomic number and mass number are wrong.
• $^{114}_{49}ln$: Incorrect, mass number decreases unexpectedly, which is not characteristic of beta decay.
• $^{113}_{50}Sn$: Incorrect, mass number is decreased, which is not possible in beta decay.
• $^{115}_{50}Sn$: Correct, matches the calculated transformation.

Therefore, the correct answer is $^{115}_{50}Sn$.