Nucleus: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Nucleus. Understanding the underlying formula is key to arriving at the correct answer below:

In $\beta$-decay, the atomic number $Z$ increases by 1 while the mass number $A$ remains constant. Two successive $\beta$-decays will increase $Z$ by 2. New $Z = 48 + 2 = 50$, and $A = 115$. The element with $Z=50$ is Tin (Sn), so the nucleus is $^{115}_{50}Sn$.