The earliest artificial radioactive substance was formed by firing alpha-particles at aluminium, $^{27}_{13}\text{Al}$. In doing so, an unstable isotope of phosphorus, $^{30}_{15}\text{P}$, was generated. What was the other product of this reaction?
- Aan $\alpha$-particle
- Ba $\beta$-particle
- Ca $\gamma$-ray
- Da neutron