Question

If an aluminum nucleus emit $\gamma$-rays .What is the resulting nucleus?

Answer 1

In the emission of gamma($\gamma$) rays, the mass number, and the atomic number of radioactive nucleus remain the same. Because gamma particles are massless as well as neutral particles.

So aluminum emits gamma $\left(\gamma \right)$ particles the mass number of aluminum remains the same and also atomic number does not change.

$$\begin{gathered} {}_{13}A{l}^{27}\to {}_{13}A{l}^{27}+\gamma \\ parentsdaughtergamma \\ nucleousnucleousparticles \end{gathered}$$

Hence, the resulting nucleus remains the same composition as the parent nucleus.